SERVER-50442 Remove ensureIndex shell function This commit also replaces all the usages of ensureIndex() with createIndex() in JS tests and JS shell

author: Rishab Joshi <rishab.joshi@mongodb.com> 2020-11-10 13:42:25 +0000
committer: Evergreen Agent <no-reply@evergreen.mongodb.com> 2020-11-12 10:38:50 +0000
commit: e69c967ff8b53634770438dfe9a5c7d13548351b (patch)
tree: cf8f6b10b2374f388d51213d172f28b4fd3d05e8 /jstests/core
parent: 916c466afac10d34e61b6ca42a12e35d7c4828f1 (diff)
download: mongo-e69c967ff8b53634770438dfe9a5c7d13548351b.tar.gz
388 files changed, 910 insertions, 910 deletions
diff --git a/jstests/core/all.js b/jstests/core/all.js
index 9d142e6e6c4..a718e2615e8 100644
--- a/jstests/core/all.js
+++ b/jstests/core/all.js
@@ -39,5 +39,5 @@ doTest = function() {
 
 doTest();
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 doTest();
diff --git a/jstests/core/all2.js b/jstests/core/all2.js
index c6b4170a7ff..44462787d20 100644
--- a/jstests/core/all2.js
+++ b/jstests/core/all2.js
@@ -29,7 +29,7 @@ check(1, {"a.x": {$all: [1, 2]}}, "F");
 check(1, {"a.x": {$all: [2, 3]}}, "G");
 check(0, {"a.x": {$all: [1, 3]}}, "H");
 
-t.ensureIndex({"a.x": 1});
+t.createIndex({"a.x": 1});
 state = "index";
 
 check(1, {"a.x": {$in: [1]}}, "A");
@@ -64,7 +64,7 @@ check(1, {"a": {$all: [1, 2]}}, "F");
 check(1, {"a": {$all: [2, 3]}}, "G");
 check(0, {"a": {$all: [1, 3]}}, "H");
 
-t.ensureIndex({"a": 1});
+t.createIndex({"a": 1});
 state = "more index";
 
 check(1, {"a": {$in: [1]}}, "A");
@@ -85,5 +85,5 @@ state = "more 2";
 t.drop();
 t.save({name: ["harry", "jack", "tom"]});
 check(0, {name: {$all: ["harry", "john"]}}, "A");
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 check(0, {name: {$all: ["harry", "john"]}}, "B");
diff --git a/jstests/core/and.js b/jstests/core/and.js
index 389aaa8d1d1..20fd583c31f 100644
--- a/jstests/core/and.js
+++ b/jstests/core/and.js
@@ -77,7 +77,7 @@ function check() {
 }
 
 check();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 check();
 
 assert.eq(1, t.find({a: 1, $and: [{a: 2}]}).itcount());
diff --git a/jstests/core/and3.js b/jstests/core/and3.js
index 6fd8e63d910..1e74db57594 100644
--- a/jstests/core/and3.js
+++ b/jstests/core/and3.js
@@ -12,7 +12,7 @@ t.drop();
 t.save({a: 1});
 t.save({a: 'foo'});
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 function checkScanMatch(query, docsExamined, n) {
     var e = t.find(query).hint({a: 1}).explain("executionStats");
diff --git a/jstests/core/andor.js b/jstests/core/andor.js
index e5e665ec398..5bac12d83ca 100644
--- a/jstests/core/andor.js
+++ b/jstests/core/andor.js
@@ -47,7 +47,7 @@ test = function() {
 };
 
 test();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test();
 
 // Test an inequality base match.
@@ -91,5 +91,5 @@ test = function() {
 t.drop();
 t.save({a: 1});
 test();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test();
diff --git a/jstests/core/apitest_dbcollection.js b/jstests/core/apitest_dbcollection.js
index 9bdbb8d0f91..00f9b6b4c4c 100644
--- a/jstests/core/apitest_dbcollection.js
+++ b/jstests/core/apitest_dbcollection.js
@@ -99,7 +99,7 @@ assert.eq(0, db.getCollection("test_db").getIndexes().length, "13");
 db.getCollection("test_db").save({a: 10});
 assert.eq(1, db.getCollection("test_db").getIndexes().length, "14");
 
-db.getCollection("test_db").ensureIndex({a: 1});
+db.getCollection("test_db").createIndex({a: 1});
 db.getCollection("test_db").save({a: 10});
 
 print(tojson(db.getCollection("test_db").getIndexes()));
@@ -109,7 +109,7 @@ db.getCollection("test_db").dropIndex({a: 1});
 assert.eq(1, db.getCollection("test_db").getIndexes().length, "16");
 
 db.getCollection("test_db").save({a: 10});
-db.getCollection("test_db").ensureIndex({a: 1});
+db.getCollection("test_db").createIndex({a: 1});
 db.getCollection("test_db").save({a: 10});
 
 assert.eq(2, db.getCollection("test_db").getIndexes().length, "17");
@@ -118,8 +118,8 @@ db.getCollection("test_db").dropIndex("a_1");
 assert.eq(1, db.getCollection("test_db").getIndexes().length, "18");
 
 db.getCollection("test_db").save({a: 10, b: 11});
-db.getCollection("test_db").ensureIndex({a: 1});
-db.getCollection("test_db").ensureIndex({b: 1});
+db.getCollection("test_db").createIndex({a: 1});
+db.getCollection("test_db").createIndex({b: 1});
 db.getCollection("test_db").save({a: 10, b: 12});
 
 assert.eq(3, db.getCollection("test_db").getIndexes().length, "19");
@@ -130,8 +130,8 @@ db.getCollection("test_db").dropIndex({a: 1});
 assert.eq(1, db.getCollection("test_db").getIndexes().length, "21");
 
 db.getCollection("test_db").save({a: 10, b: 11});
-db.getCollection("test_db").ensureIndex({a: 1});
-db.getCollection("test_db").ensureIndex({b: 1});
+db.getCollection("test_db").createIndex({a: 1});
+db.getCollection("test_db").createIndex({b: 1});
 db.getCollection("test_db").save({a: 10, b: 12});
 
 assert.eq(3, db.getCollection("test_db").getIndexes().length, "22");
@@ -179,7 +179,7 @@ assert.eq(10,
 // indexDetails - If true, includes 'indexDetails' field in results. Default: false.
 t.drop();
 t.save({a: 1});
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 collectionStats = assert.commandWorked(t.stats());
 assert(!collectionStats.hasOwnProperty('indexDetails'),
        'unexpected indexDetails found in db.collection.stats() result: ' + tojson(collectionStats));
diff --git a/jstests/core/array1.js b/jstests/core/array1.js
index 27addaed616..d25b609f3d3 100644
--- a/jstests/core/array1.js
+++ b/jstests/core/array1.js
@@ -14,6 +14,6 @@ assert.eq(1, coll.find(x).count());
 assert.commandWorked(coll.insert(x));
 assert.eq(2, coll.find(x).count());
 
-assert.commandWorked(coll.ensureIndex({a: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
 assert.eq(2, coll.find(x).count());
 }());
diff --git a/jstests/core/array_match1.js b/jstests/core/array_match1.js
index b6a0930968e..0c56e8d4c34 100644
--- a/jstests/core/array_match1.js
+++ b/jstests/core/array_match1.js
@@ -16,7 +16,7 @@ function test(f, m) {
 }
 
 test("a", "A");
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test("a", "B");
 
 t.drop();
@@ -26,5 +26,5 @@ t.insert({_id: 2, a: {b: [6, 6]}});
 t.insert({_id: 3, a: {b: [5, 5]}});
 
 test("a.b", "C");
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test("a.b", "D");
diff --git a/jstests/core/array_match3.js b/jstests/core/array_match3.js
index 837341afc8a..4990bdd90fd 100644
--- a/jstests/core/array_match3.js
+++ b/jstests/core/array_match3.js
@@ -9,5 +9,5 @@ t.save({a: [5]});
 assert.eq(2, t.count({'a.0': 5}));
 
 // Test with index.
-t.ensureIndex({'a.0': 1});
+t.createIndex({'a.0': 1});
 assert.eq(2, t.count({'a.0': 5}));
diff --git a/jstests/core/array_match4.js b/jstests/core/array_match4.js
index 821e9a4f4eb..54581a14b97 100644
--- a/jstests/core/array_match4.js
+++ b/jstests/core/array_match4.js
@@ -16,7 +16,7 @@ assert.eq(1, t.find(query_gte).itcount(), '$gte (without index)');
 // with index
 //
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 assert.eq(1, t.find({a: [1, 2]}).count(), '$eq (with index)');
 
 // display explain output (for index bounds)
diff --git a/jstests/core/arrayfind1.js b/jstests/core/arrayfind1.js
index c9d75c17f65..4e9330549ae 100644
--- a/jstests/core/arrayfind1.js
+++ b/jstests/core/arrayfind1.js
@@ -26,7 +26,7 @@ t.save({a: [{x: 4}]});
 assert.eq(1, t.find({a: {$elemMatch: {x: 2}}}).count(), "B1");
 assert.eq(2, t.find({a: {$elemMatch: {x: {$gt: 2}}}}).count(), "B2");
 
-t.ensureIndex({"a.x": 1});
+t.createIndex({"a.x": 1});
 assert.eq(1, t.find({a: {$elemMatch: {x: 2}}}).count(), "D1");
 assert.eq(3, t.find({"a.x": 1}).count(), "D2.1");
 assert.eq(3, t.find({"a.x": {$gt: 1}}).count(), "D2.2");
diff --git a/jstests/core/arrayfind2.js b/jstests/core/arrayfind2.js
index bbceffaa126..38de844f6f4 100644
--- a/jstests/core/arrayfind2.js
+++ b/jstests/core/arrayfind2.js
@@ -25,5 +25,5 @@ t.save({a: [{x: 3}, {x: 5}]});
 t.save({a: [{x: 3}, {x: 6}]});
 
 go("no index");
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 go("index(a)");
diff --git a/jstests/core/arrayfind3.js b/jstests/core/arrayfind3.js
index 312ae4c0349..6dba0bf625f 100644
--- a/jstests/core/arrayfind3.js
+++ b/jstests/core/arrayfind3.js
@@ -8,7 +8,7 @@ t.save({a: [1, 4, 6]});
 assert.eq(2, t.find({a: {$gte: 3, $lte: 5}}).itcount(), "A1");
 assert.eq(1, t.find({a: {$elemMatch: {$gte: 3, $lte: 5}}}).itcount(), "A2");
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(2, t.find({a: {$gte: 3, $lte: 5}}).itcount(), "B1");
 assert.eq(1, t.find({a: {$elemMatch: {$gte: 3, $lte: 5}}}).itcount(), "B2");
diff --git a/jstests/core/arrayfind4.js b/jstests/core/arrayfind4.js
index 4fac0b63755..2d7c0e03668 100644
--- a/jstests/core/arrayfind4.js
+++ b/jstests/core/arrayfind4.js
@@ -8,7 +8,7 @@ t = db.jstests_arrayfind4;
 t.drop();
 
 t.save({a: []});
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(1, t.find({a: []}).hint({$natural: 1}).itcount());
 assert.eq(1, t.find({a: []}).hint({a: 1}).itcount());
diff --git a/jstests/core/arrayfind5.js b/jstests/core/arrayfind5.js
index 9f8800a0c69..171fe49e1f8 100644
--- a/jstests/core/arrayfind5.js
+++ b/jstests/core/arrayfind5.js
@@ -16,12 +16,12 @@ function check(nullElemMatch) {
 
 t.save({a: [{}, {b: 1}]});
 check(true);
-t.ensureIndex({'a.b': 1});
+t.createIndex({'a.b': 1});
 check(true);
 
 t.drop();
 
 t.save({a: [5, {b: 1}]});
 check(false);
-t.ensureIndex({'a.b': 1});
+t.createIndex({'a.b': 1});
 check(false);
diff --git a/jstests/core/arrayfind6.js b/jstests/core/arrayfind6.js
index f01271b6673..bd91859c9dc 100644
--- a/jstests/core/arrayfind6.js
+++ b/jstests/core/arrayfind6.js
@@ -17,5 +17,5 @@ function checkElemMatchMatches() {
 }
 
 checkElemMatchMatches();
-t.ensureIndex({'a.b': 1});
+t.createIndex({'a.b': 1});
 checkElemMatchMatches();
diff --git a/jstests/core/arrayfind7.js b/jstests/core/arrayfind7.js
index 699f8c9586d..be2061c5c0d 100644
--- a/jstests/core/arrayfind7.js
+++ b/jstests/core/arrayfind7.js
@@ -11,7 +11,7 @@ function checkElemMatchMatches() {
 
 // The document is matched using nested $elemMatch expressions, with and without an index.
 checkElemMatchMatches();
-t.ensureIndex({'a.b.c': 1});
+t.createIndex({'a.b.c': 1});
 checkElemMatchMatches();
 
 function checkElemMatch(index, document, query) {
@@ -19,7 +19,7 @@ function checkElemMatch(index, document, query) {
     t.drop();
     t.save(document);
     assert.eq(1, t.count(query));
-    t.ensureIndex(index);
+    t.createIndex(index);
     assert.eq(1, t.count(query));
     t.save({a: {b: {c: [10, 11]}}});  // Make the index multikey.
     assert.eq(1, t.count(query));
diff --git a/jstests/core/arrayfind9.js b/jstests/core/arrayfind9.js
index 98396701dce..5406ae8c1d1 100644
--- a/jstests/core/arrayfind9.js
+++ b/jstests/core/arrayfind9.js
@@ -25,8 +25,8 @@ assert.eq(1, t.count({a: {$elemMatch: {'0': 'x'}}}));
 // Matching multiple values of a nested array.
 t.drop();
 t.save({a: [{b: [0, 2]}]});
-t.ensureIndex({a: 1});
-t.ensureIndex({'a.b': 1});
+t.createIndex({a: 1});
+t.createIndex({'a.b': 1});
 plans = [{$natural: 1}, {a: 1}, {'a.b': 1}];
 for (i in plans) {
     p = plans[i];
diff --git a/jstests/core/arrayfinda.js b/jstests/core/arrayfinda.js
index f2939d0c1ba..163af3d8d29 100644
--- a/jstests/core/arrayfinda.js
+++ b/jstests/core/arrayfinda.js
@@ -16,6 +16,6 @@ assertExpectedMatch(t.find({a: {$elemMatch: {b: {$gte: 1}}}}));
 assertExpectedMatch(t.find({a: {$elemMatch: {b: 1}}}));
 
 // $elemMatch is not used to perform key matching.  SERVER-6001
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 assertExpectedMatch(t.find({a: {$elemMatch: {b: {$gte: 1}}}}).hint({a: 1}));
 assertExpectedMatch(t.find({a: {$elemMatch: {b: 1}}}).hint({a: 1}));
diff --git a/jstests/core/arrayfindb.js b/jstests/core/arrayfindb.js
index c9456509487..7277f51c4f4 100644
--- a/jstests/core/arrayfindb.js
+++ b/jstests/core/arrayfindb.js
@@ -12,7 +12,7 @@ assert.eq(0,
           t.find({a: {$elemMatch: {b: {$gte: 2, $lt: 4}, c: 25}}}).itcount(),
           "Case #1: wrong number of results returned -- unindexed");
 
-t.ensureIndex({"a.b": 1, "a.c": 1});
+t.createIndex({"a.b": 1, "a.c": 1});
 assert.eq(0,
           t.find({a: {$elemMatch: {b: {$gte: 2, $lt: 4}, c: 25}}}).itcount(),
           "Case #1: wrong number of results returned -- indexed");
@@ -26,8 +26,8 @@ assert.eq(2,
           t.find({a: {$elemMatch: {$or: [{b: 2}, {c: 2}]}}}).itcount(),
           "Case #2: wrong number of results returned -- unindexed");
 
-t.ensureIndex({"a.b": 1});
-t.ensureIndex({"a.c": 1});
+t.createIndex({"a.b": 1});
+t.createIndex({"a.c": 1});
 assert.eq(2,
           t.find({a: {$elemMatch: {$or: [{b: 2}, {c: 2}]}}}).itcount(),
           "Case #2: wrong number of results returned -- indexed");
diff --git a/jstests/core/bad_index_plugin.js b/jstests/core/bad_index_plugin.js
index 7ecfe76c198..c9cd549cc03 100644
--- a/jstests/core/bad_index_plugin.js
+++ b/jstests/core/bad_index_plugin.js
@@ -1,10 +1,10 @@
 // SERVER-5826 ensure you can't build an index with a non-existent plugin
 t = db.bad_index_plugin;
 
-assert.commandWorked(t.ensureIndex({good: 1}));
+assert.commandWorked(t.createIndex({good: 1}));
 assert.eq(t.getIndexes().length, 2);  // good + _id
 
-var err = t.ensureIndex({bad: 'bad'});
+var err = t.createIndex({bad: 'bad'});
 assert.commandFailed(err);
 assert(err.code >= 0);
 
diff --git a/jstests/core/basic7.js b/jstests/core/basic7.js
index bfe82ccda17..dc6f18cc95b 100644
--- a/jstests/core/basic7.js
+++ b/jstests/core/basic7.js
@@ -3,7 +3,7 @@ t = db.basic7;
 t.drop();
 
 t.save({a: 1});
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(t.find().toArray()[0].a, 1);
 assert.eq(t.find().arrayAccess(0).a, 1);
diff --git a/jstests/core/batch_size.js b/jstests/core/batch_size.js
index 11ea9cd2380..c0afc382975 100644
--- a/jstests/core/batch_size.js
+++ b/jstests/core/batch_size.js
@@ -46,7 +46,7 @@ assert.eq(1, t.find().batchSize(-1).itcount());
 assert.eq(2, t.find().batchSize(-2).itcount());
 
 // Run the tests with the index twice in order to double check plan caching.
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 for (var i = 0; i < 2; i++) {
     runIndexedTests();
 }
@@ -54,8 +54,8 @@ for (var i = 0; i < 2; i++) {
 // The next tests make sure that we obey limit and batchSize properly when the sort could be
 // either indexed or unindexed.
 t.drop();
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 for (var i = 0; i < 100; i++) {
     t.save({_id: i, a: i, b: 1});
@@ -118,8 +118,8 @@ for (var i = 0; i < nDocs; i++) {
 }
 
 // Two indices needed in order to trigger plan ranking. Neither index provides the sort order.
-t.ensureIndex({x: 1});
-t.ensureIndex({y: 1});
+t.createIndex({x: 1});
+t.createIndex({y: 1});
 
 // We should only buffer 3 docs in memory.
 var cursor = t.find({x: 1, y: 1}).sort({z: -1}).limit(3);
diff --git a/jstests/core/batch_write_command_insert.js b/jstests/core/batch_write_command_insert.js
index cf1b0013ef7..664ff73958a 100644
--- a/jstests/core/batch_write_command_insert.js
+++ b/jstests/core/batch_write_command_insert.js
@@ -179,7 +179,7 @@ assert(resultNOK(result), tojson(result));
 //
 // Should fail single insert due to duplicate key
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 coll.insert({a: 1});
 request = {
     insert: coll.getName(),
@@ -194,7 +194,7 @@ assert.eq(coll.count(), 1);
 //
 // Fail with duplicate key error on multiple document inserts, ordered false
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 request = {
     insert: coll.getName(),
     documents: [{a: 1}, {a: 1}, {a: 1}],
@@ -220,7 +220,7 @@ assert.eq(coll.count(), 1);
 //
 // Fail with duplicate key error on multiple document inserts, ordered true
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 request = {
     insert: coll.getName(),
     documents: [{a: 1}, {a: 1}, {a: 1}],
@@ -241,7 +241,7 @@ assert.eq(coll.count(), 1);
 //
 // Ensure _id is the first field in all documents
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 request = {
     insert: coll.getName(),
     documents: [{a: 1}, {a: 2, _id: 2}]
diff --git a/jstests/core/batch_write_command_update.js b/jstests/core/batch_write_command_update.js
index edb90be8523..f6372a651af 100644
--- a/jstests/core/batch_write_command_update.js
+++ b/jstests/core/batch_write_command_update.js
@@ -235,7 +235,7 @@ assert.eq(1, coll.count());
 //
 // Upsert fail due to duplicate key index, w:1, ordered:true
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 request = {
     update: coll.getName(),
     updates: [
@@ -266,7 +266,7 @@ assert.eq(1, coll.count({_id: result.upserted[1]._id}));
 //
 // Upsert fail due to duplicate key index, w:1, ordered:false
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 request = {
     update: coll.getName(),
     updates: [
diff --git a/jstests/core/batch_write_command_w0.js b/jstests/core/batch_write_command_w0.js
index 01b9cb5f165..ca2522bbe01 100644
--- a/jstests/core/batch_write_command_w0.js
+++ b/jstests/core/batch_write_command_w0.js
@@ -76,7 +76,7 @@ countEventually(coll, 2);
 //
 // Upsert fail due to duplicate key index, w:0, ordered:true
 coll.drop();
-coll.ensureIndex({a: 1}, {unique: true});
+coll.createIndex({a: 1}, {unique: true});
 request = {
     update: coll.getName(),
     updates: [
diff --git a/jstests/core/bulk_api_ordered.js b/jstests/core/bulk_api_ordered.js
index 2957195065d..d3a484c2b12 100644
--- a/jstests/core/bulk_api_ordered.js
+++ b/jstests/core/bulk_api_ordered.js
@@ -80,7 +80,7 @@ var executeTests = function() {
 
     // Create unique index
     coll.remove({});
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 
     /**
      * Single error ordered bulk operation
@@ -118,7 +118,7 @@ var executeTests = function() {
     // Create unique index
     coll.dropIndexes();
     coll.remove({});
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 
     /**
      * Multiple error ordered bulk operation
@@ -152,7 +152,7 @@ var executeTests = function() {
     // Create unique index
     coll.dropIndexes();
     coll.remove({});
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 };
 
 var buildVersion = parseInt(db.runCommand({buildInfo: 1}).versionArray.slice(0, 3).join(""), 10);
diff --git a/jstests/core/bulk_api_unordered.js b/jstests/core/bulk_api_unordered.js
index 6db2a607a25..04e002306e5 100644
--- a/jstests/core/bulk_api_unordered.js
+++ b/jstests/core/bulk_api_unordered.js
@@ -85,7 +85,7 @@ var executeTests = function() {
 
     // Create unique index
     coll.remove({});
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 
     /**
      * Single error unordered bulk operation
@@ -118,7 +118,7 @@ var executeTests = function() {
     // Create unique index
     coll.dropIndexes();
     coll.remove({});
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 
     /**
      * Multiple error unordered bulk operation
@@ -168,7 +168,7 @@ var executeTests = function() {
     // Create unique index
     coll.dropIndexes();
     coll.remove({});
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 };
 
 var buildVersion = parseInt(db.runCommand({buildInfo: 1}).versionArray.slice(0, 3).join(""), 10);
diff --git a/jstests/core/capped5.js b/jstests/core/capped5.js
index 0efb957ae6c..163aa684fbe 100644
--- a/jstests/core/capped5.js
+++ b/jstests/core/capped5.js
@@ -9,8 +9,8 @@ t.insert({_id: 5, x: 11, z: 52});
 assert.eq(1, t.getIndexKeys().length, "A0");  // now we assume _id index even on capped coll
 assert.eq(52, t.findOne({x: 11}).z, "A1");
 
-t.ensureIndex({_id: 1});
-t.ensureIndex({x: 1});
+t.createIndex({_id: 1});
+t.createIndex({x: 1});
 
 assert.eq(52, t.findOne({x: 11}).z, "B1");
 assert.eq(52, t.findOne({_id: 5}).z, "B2");
@@ -26,14 +26,14 @@ t.drop();
 db.createCollection(tn, {capped: true, size: 1024 * 1024 * 1});
 t.insert({_id: 5, x: 11});
 t.insert({_id: 6, x: 12});
-t.ensureIndex({x: 1}, {unique: true});
+t.createIndex({x: 1}, {unique: true});
 assert.eq(2, t.getIndexes().length);  // now we assume _id index
 assert.eq(2, t.find().hint({x: 1}).toArray().length);
 
 // SERVER-525 (closed) unique indexes in capped collection
 t.drop();
 db.createCollection(tn, {capped: true, size: 1024 * 1024 * 1});
-t.ensureIndex({_id: 1});  // note we assume will be automatically unique because it is _id
+t.createIndex({_id: 1});  // note we assume will be automatically unique because it is _id
 t.insert({_id: 5, x: 11});
 t.insert({_id: 5, x: 12});
 assert.eq(1, t.find().toArray().length);
diff --git a/jstests/core/capped_empty.js b/jstests/core/capped_empty.js
index 99e08f217ed..93657b4a67f 100644
--- a/jstests/core/capped_empty.js
+++ b/jstests/core/capped_empty.js
@@ -14,7 +14,7 @@ db.createCollection(t.getName(), {capped: true, size: 100});
 t.insert({x: 1});
 t.insert({x: 2});
 t.insert({x: 3});
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 assert.eq(3, t.count());
 
diff --git a/jstests/core/cappeda.js b/jstests/core/cappeda.js
index f506d5416b1..1061ba0a1d6 100644
--- a/jstests/core/cappeda.js
+++ b/jstests/core/cappeda.js
@@ -22,7 +22,7 @@ function u() {
 // assert.throws( q , [] , "A1" );
 // assert.throws( u , [] , "B1" );
 
-t.ensureIndex({_id: 1});
+t.createIndex({_id: 1});
 
 assert.eq(1, q().x);
 q();
diff --git a/jstests/core/check_shard_index.js b/jstests/core/check_shard_index.js
index f187a6210d0..e64beee77f8 100644
--- a/jstests/core/check_shard_index.js
+++ b/jstests/core/check_shard_index.js
@@ -16,7 +16,7 @@ f.drop();
 //
 
 f.drop();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 assert.eq(0, f.count(), "1. initial count should be zero");
 
 res = db.runCommand({checkShardingIndex: "test.jstests_shardingindex", keyPattern: {x: 1, y: 1}});
@@ -32,7 +32,7 @@ assert.eq(true, res.ok, "1b");
 //
 
 f.drop();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 assert.eq(0, f.count(), "2. initial count should be zero");
 
 f.save({x: 1, y: 1});
@@ -56,7 +56,7 @@ assert(res.idskip, "2d " + tojson(res));
 //
 
 f.drop();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 assert.eq(0, f.count(), "3. initial count should be zero");
 
 f.save({x: 1, y: 1});
@@ -68,7 +68,7 @@ assert.eq(false, res.ok, "3a " + tojson(res));
 
 f.remove({y: 2});
 f.dropIndex({x: 1, y: 1});
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 
 assert.eq(1, f.count(), "3. count after removing array value should be 1");
 res = db.runCommand({checkShardingIndex: "test.jstests_shardingindex", keyPattern: {x: 1, y: 1}});
@@ -85,7 +85,7 @@ assert.eq(false, res.ok, "3c " + tojson(res));
 //
 
 f.drop();
-f.ensureIndex({x: 1, y: 1, z: 1});
+f.createIndex({x: 1, y: 1, z: 1});
 assert.eq(0, f.count(), "4. initial count should be zero");
 
 f.save({x: 1, y: 1, z: 1});
@@ -110,7 +110,7 @@ assert.eq(false, res.ok, "4e " + tojson(res));
 
 f.remove({y: 2});
 f.dropIndex({x: 1, y: 1, z: 1});
-f.ensureIndex({x: 1, y: 1, z: 1});
+f.createIndex({x: 1, y: 1, z: 1});
 
 assert.eq(1, f.count(), "4. count after removing array value should be 1");
 res = db.runCommand(
@@ -131,7 +131,7 @@ assert.eq(false, res.ok, "4i " + tojson(res));
 f.remove({x: 3});
 // Necessary so that the index is no longer marked as multikey
 f.dropIndex({x: 1, y: 1, z: 1});
-f.ensureIndex({x: 1, y: 1, z: 1});
+f.createIndex({x: 1, y: 1, z: 1});
 
 assert.eq(1, f.count(), "4. count after removing array value should be 1 again");
 res = db.runCommand(
diff --git a/jstests/core/collation.js b/jstests/core/collation.js
index 5cfedcc8e1f..44e8092f75e 100644
--- a/jstests/core/collation.js
+++ b/jstests/core/collation.js
@@ -99,7 +99,7 @@ assert.eq(collectionInfos[0].options.collation, {
 });
 
 // Ensure that an index with no collation inherits the collection-default collation.
-assert.commandWorked(coll.ensureIndex({a: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
 assertIndexHasCollation({a: 1}, {
     locale: "fr_CA",
     caseLevel: false,
@@ -115,7 +115,7 @@ assertIndexHasCollation({a: 1}, {
 
 // Ensure that an index which specifies an overriding collation does not use the collection
 // default.
-assert.commandWorked(coll.ensureIndex({b: 1}, {collation: {locale: "en_US"}}));
+assert.commandWorked(coll.createIndex({b: 1}, {collation: {locale: "en_US"}}));
 assertIndexHasCollation({b: 1}, {
     locale: "en_US",
     caseLevel: false,
@@ -131,11 +131,11 @@ assertIndexHasCollation({b: 1}, {
 
 // Ensure that an index which specifies the "simple" collation as an overriding collation still
 // does not use the collection default.
-assert.commandWorked(coll.ensureIndex({d: 1}, {collation: {locale: "simple"}}));
+assert.commandWorked(coll.createIndex({d: 1}, {collation: {locale: "simple"}}));
 assertIndexHasCollation({d: 1}, {locale: "simple"});
 
 // Ensure that a v=1 index doesn't inherit the collection-default collation.
-assert.commandWorked(coll.ensureIndex({c: 1}, {v: 1}));
+assert.commandWorked(coll.createIndex({c: 1}, {v: 1}));
 assertIndexHasCollation({c: 1}, {locale: "simple"});
 
 // Test that all indexes retain their current collation when the collection is re-indexed. (Only
@@ -177,20 +177,20 @@ coll.drop();
 //
 
 // Attempting to build an index with an invalid collation should fail.
-assert.commandFailed(coll.ensureIndex({a: 1}, {collation: "not an object"}));
-assert.commandFailed(coll.ensureIndex({a: 1}, {collation: {}}));
-assert.commandFailed(coll.ensureIndex({a: 1}, {collation: {blah: 1}}));
-assert.commandFailed(coll.ensureIndex({a: 1}, {collation: {locale: "en", blah: 1}}));
-assert.commandFailed(coll.ensureIndex({a: 1}, {collation: {locale: "xx"}}));
-assert.commandFailed(coll.ensureIndex({a: 1}, {collation: {locale: "en", strength: 99}}));
+assert.commandFailed(coll.createIndex({a: 1}, {collation: "not an object"}));
+assert.commandFailed(coll.createIndex({a: 1}, {collation: {}}));
+assert.commandFailed(coll.createIndex({a: 1}, {collation: {blah: 1}}));
+assert.commandFailed(coll.createIndex({a: 1}, {collation: {locale: "en", blah: 1}}));
+assert.commandFailed(coll.createIndex({a: 1}, {collation: {locale: "xx"}}));
+assert.commandFailed(coll.createIndex({a: 1}, {collation: {locale: "en", strength: 99}}));
 
 // Attempting to create an index whose collation version does not match the collator version
 // produced by ICU should result in failure with a special error code.
 assert.commandFailedWithCode(
-    coll.ensureIndex({a: 1}, {collation: {locale: "en", version: "unknownVersion"}}),
+    coll.createIndex({a: 1}, {collation: {locale: "en", version: "unknownVersion"}}),
     ErrorCodes.IncompatibleCollationVersion);
 
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "en_US"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "en_US"}}));
 assertIndexHasCollation({a: 1}, {
     locale: "en_US",
     caseLevel: false,
@@ -335,7 +335,7 @@ assert.eq(0, coll.aggregate([{$match: {str: "FOO"}}], {collation: {locale: "simp
 // default collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "en_US"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "en_US"}}));
 var explain = coll.explain("queryPlanner").aggregate([{$match: {a: "foo"}}]);
 assert(isIxscan(db, explain.queryPlanner.winningPlan));
 
@@ -343,7 +343,7 @@ assert(isIxscan(db, explain.queryPlanner.winningPlan));
 // collation is incompatible with index collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "simple"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "simple"}}));
 var explain = coll.explain("queryPlanner").aggregate([{$match: {a: "foo"}}]);
 assert(isCollscan(db, explain.queryPlanner.winningPlan));
 
@@ -505,7 +505,7 @@ assert.eq(1, coll.distinct("_id", {str: "foo"}, {collation: {locale: "simple"}})
 // default collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "en_US"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "en_US"}}));
 var explain = coll.explain("queryPlanner").distinct("a");
 assert(planHasStage(db, explain.queryPlanner.winningPlan, "DISTINCT_SCAN"));
 assert(planHasStage(db, explain.queryPlanner.winningPlan, "FETCH"));
@@ -534,7 +534,7 @@ assert(!planHasStage(db, explain.queryPlanner.winningPlan, "FETCH"));
 // incompatible with index collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "simple"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "simple"}}));
 var explain = coll.explain("queryPlanner").distinct("a");
 assert(isCollscan(db, explain.queryPlanner.winningPlan));
 
@@ -608,7 +608,7 @@ if (db.getMongo().useReadCommands()) {
               coll.find({str: {$ne: "FOO"}}).collation({locale: "en_US", strength: 2}).itcount());
 
     // Find should return correct results when collation specified and compatible index exists.
-    assert.commandWorked(coll.ensureIndex({str: 1}, {collation: {locale: "en_US", strength: 2}}));
+    assert.commandWorked(coll.createIndex({str: 1}, {collation: {locale: "en_US", strength: 2}}));
     assert.eq(0, coll.find({str: "FOO"}).hint({str: 1}).itcount());
     assert.eq(0, coll.find({str: "FOO"}).collation({locale: "en_US"}).hint({str: 1}).itcount());
     assert.eq(
@@ -623,7 +623,7 @@ if (db.getMongo().useReadCommands()) {
 
     // Find should return correct results when collation specified and compatible partial index
     // exists.
-    assert.commandWorked(coll.ensureIndex({str: 1}, {
+    assert.commandWorked(coll.createIndex({str: 1}, {
         partialFilterExpression: {str: {$lte: "FOO"}},
         collation: {locale: "en_US", strength: 2}
     }));
@@ -644,7 +644,7 @@ if (db.getMongo().useReadCommands()) {
 
     // Ensure results from an index that doesn't match the query collation are sorted to match
     // the requested collation.
-    assert.commandWorked(coll.ensureIndex({a: 1}));
+    assert.commandWorked(coll.createIndex({a: 1}));
     var res =
         coll.find({a: {'$exists': true}}, {_id: 0}).collation({locale: "en_US", strength: 3}).sort({
             a: 1
@@ -746,7 +746,7 @@ if (db.getMongo().useReadCommands()) {
 // collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "en_US"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "en_US"}}));
 var explain = coll.find({a: "foo"}).explain("queryPlanner");
 assert(isIxscan(db, explain.queryPlanner.winningPlan));
 
@@ -754,7 +754,7 @@ assert(isIxscan(db, explain.queryPlanner.winningPlan));
 // collation is "simple".
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "simple"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "simple"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "simple"}}));
 var explain = coll.find({a: "foo"}).explain("queryPlanner");
 assert(isIxscan(db, explain.queryPlanner.winningPlan));
 
@@ -762,7 +762,7 @@ assert(isIxscan(db, explain.queryPlanner.winningPlan));
 // collection has a non-"simple" default collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "simple"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "simple"}}));
 var explain = coll.find({a: "foo"}).explain("queryPlanner");
 assert(isCollscan(db, explain.queryPlanner.winningPlan));
 
@@ -770,7 +770,7 @@ assert(isCollscan(db, explain.queryPlanner.winningPlan));
 // non-"simple" default collation.
 coll.drop();
 assert.commandWorked(db.createCollection(coll.getName(), {collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({a: 1}, {collation: {locale: "simple"}}));
+assert.commandWorked(coll.createIndex({a: 1}, {collation: {locale: "simple"}}));
 var explain = coll.find({a: "foo"}).collation({locale: "simple"}).explain("queryPlanner");
 assert(isIxscan(db, explain.queryPlanner.winningPlan));
 
@@ -1314,14 +1314,14 @@ const geoNearStage = {
 
 // $geoNear should return correct results when collation specified and string predicate not
 // indexed.
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 assert.eq(0, coll.aggregate([geoNearStage]).itcount());
 assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", strength: 2}}).itcount());
 
 // $geoNear should return correct results when no collation specified and string predicate
 // indexed.
 assert.commandWorked(coll.dropIndexes());
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere", str: 1}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere", str: 1}));
 assert.eq(0, coll.aggregate([geoNearStage]).itcount());
 assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", strength: 2}}).itcount());
 
@@ -1329,7 +1329,7 @@ assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", streng
 // incompatible with string predicate.
 assert.commandWorked(coll.dropIndexes());
 assert.commandWorked(
-    coll.ensureIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 3}}));
+    coll.createIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 3}}));
 assert.eq(0, coll.aggregate([geoNearStage]).itcount());
 assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", strength: 2}}).itcount());
 
@@ -1337,7 +1337,7 @@ assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", streng
 // compatible with string predicate.
 assert.commandWorked(coll.dropIndexes());
 assert.commandWorked(
-    coll.ensureIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 2}}));
+    coll.createIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 2}}));
 assert.eq(0, coll.aggregate([geoNearStage]).itcount());
 assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", strength: 2}}).itcount());
 
@@ -1346,7 +1346,7 @@ assert.eq(1, coll.aggregate([geoNearStage], {collation: {locale: "en_US", streng
 coll.drop();
 assert.commandWorked(
     db.createCollection(coll.getName(), {collation: {locale: "en_US", strength: 2}}));
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 assert.commandWorked(coll.insert({geo: {type: "Point", coordinates: [0, 0]}, str: "abc"}));
 assert.eq(1, coll.aggregate([geoNearStage]).itcount());
 
@@ -1355,7 +1355,7 @@ assert.eq(1, coll.aggregate([geoNearStage]).itcount());
 coll.drop();
 assert.commandWorked(
     db.createCollection(coll.getName(), {collation: {locale: "en_US", strength: 2}}));
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 assert.commandWorked(coll.insert({geo: {type: "Point", coordinates: [0, 0]}, str: "abc"}));
 assert.eq(0, coll.aggregate([geoNearStage], {collation: {locale: "simple"}}).itcount());
 
@@ -1378,7 +1378,7 @@ if (db.getMongo().useReadCommands()) {
     // predicate not indexed.
     coll.drop();
     assert.commandWorked(coll.insert({geo: {type: "Point", coordinates: [0, 0]}, str: "abc"}));
-    assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+    assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
     assert.eq(
         0,
         coll.find(
@@ -1394,7 +1394,7 @@ if (db.getMongo().useReadCommands()) {
     // Find with $nearSphere should return correct results when no collation specified and
     // string predicate indexed.
     assert.commandWorked(coll.dropIndexes());
-    assert.commandWorked(coll.ensureIndex({geo: "2dsphere", str: 1}));
+    assert.commandWorked(coll.createIndex({geo: "2dsphere", str: 1}));
     assert.eq(
         0,
         coll.find(
@@ -1411,7 +1411,7 @@ if (db.getMongo().useReadCommands()) {
     // collation on index is incompatible with string predicate.
     assert.commandWorked(coll.dropIndexes());
     assert.commandWorked(
-        coll.ensureIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 3}}));
+        coll.createIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 3}}));
     assert.eq(
         0,
         coll.find(
@@ -1428,7 +1428,7 @@ if (db.getMongo().useReadCommands()) {
     // collation on index is compatible with string predicate.
     assert.commandWorked(coll.dropIndexes());
     assert.commandWorked(
-        coll.ensureIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 2}}));
+        coll.createIndex({geo: "2dsphere", str: 1}, {collation: {locale: "en_US", strength: 2}}));
     assert.eq(
         0,
         coll.find(
@@ -1886,7 +1886,7 @@ if (db.getMongo().useReadCommands()) {
 
     // Ensure results from index with min/max query are sorted to match requested collation.
     coll.drop();
-    assert.commandWorked(coll.ensureIndex({a: 1, b: 1}));
+    assert.commandWorked(coll.createIndex({a: 1, b: 1}));
     assert.commandWorked(
         coll.insert([{a: 1, b: 1}, {a: 1, b: 2}, {a: 1, b: "A"}, {a: 1, b: "a"}, {a: 2, b: 2}]));
     var expected = [{a: 1, b: 1}, {a: 1, b: 2}, {a: 1, b: "a"}, {a: 1, b: "A"}, {a: 2, b: 2}];
diff --git a/jstests/core/collmod.js b/jstests/core/collmod.js
index c70a806c2d7..2f71b39c485 100644
--- a/jstests/core/collmod.js
+++ b/jstests/core/collmod.js
@@ -53,7 +53,7 @@ function findCollectionInfo() {
 assert.commandFailed(t.runCommand('collmod', {NotARealOption: 1}));
 
 // add a TTL index
-t.ensureIndex({a: 1}, {"name": "index1", "expireAfterSeconds": 50});
+t.createIndex({a: 1}, {"name": "index1", "expireAfterSeconds": 50});
 assert(findTTL({a: 1}, 50), "TTL index not added");
 
 // try to modify it with a bad key pattern
@@ -98,7 +98,7 @@ assert.commandFailed(db.runCommand({
 
 // try to modify a faulty TTL index with a non-numeric expireAfterSeconds field
 t.dropIndex({a: 1});
-t.ensureIndex({a: 1}, {"expireAfterSeconds": "50"});
+t.createIndex({a: 1}, {"expireAfterSeconds": "50"});
 var res =
     db.runCommand({"collMod": coll, "index": {"keyPattern": {a: 1}, "expireAfterSeconds": 100}});
 debug(res);
@@ -106,7 +106,7 @@ assert.eq(0, res.ok, "shouldn't be able to modify faulty index spec");
 
 // try with new index, this time set expireAfterSeconds
 t.dropIndex({a: 1});
-t.ensureIndex({a: 1}, {"expireAfterSeconds": 50});
+t.createIndex({a: 1}, {"expireAfterSeconds": 50});
 var res =
     db.runCommand({"collMod": coll, "index": {"keyPattern": {a: 1}, "expireAfterSeconds": 100}});
 debug(res);
diff --git a/jstests/core/compact_keeps_indexes.js b/jstests/core/compact_keeps_indexes.js
index 4371513b3d9..f4f59165272 100644
--- a/jstests/core/compact_keeps_indexes.js
+++ b/jstests/core/compact_keeps_indexes.js
@@ -15,7 +15,7 @@ var coll = db.compact_keeps_indexes;
 
 coll.drop();
 coll.insert({_id: 1, x: 1});
-coll.ensureIndex({x: 1});
+coll.createIndex({x: 1});
 
 assert.eq(coll.getIndexes().length, 2);
 
diff --git a/jstests/core/count.js b/jstests/core/count.js
index 523b0743c3f..c34f8721cef 100644
--- a/jstests/core/count.js
+++ b/jstests/core/count.js
@@ -17,13 +17,13 @@ assert.eq(2, coll.count());
 
 coll.drop();
 assert.commandWorked(coll.insert({a: true, b: false}));
-assert.commandWorked(coll.ensureIndex({b: 1, a: 1}));
+assert.commandWorked(coll.createIndex({b: 1, a: 1}));
 assert.eq(1, coll.find({a: true, b: false}).count());
 assert.eq(1, coll.find({b: false, a: true}).count());
 
 coll.drop();
 assert.commandWorked(coll.insert({a: true, b: false}));
-assert.commandWorked(coll.ensureIndex({b: 1, a: 1, c: 1}));
+assert.commandWorked(coll.createIndex({b: 1, a: 1, c: 1}));
 
 assert.eq(1, coll.find({a: true, b: false}).count());
 assert.eq(1, coll.find({b: false, a: true}).count());
diff --git a/jstests/core/count4.js b/jstests/core/count4.js
index ac0b3d3491f..2bb35190bd8 100644
--- a/jstests/core/count4.js
+++ b/jstests/core/count4.js
@@ -13,7 +13,7 @@ q = {
 assert.eq(50, t.find(q).count(), "A");
 assert.eq(50, t.find(q).itcount(), "B");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 assert.eq(50, t.find(q).count(), "C");
 assert.eq(50, t.find(q).itcount(), "D");
diff --git a/jstests/core/count5.js b/jstests/core/count5.js
index b89eb88d494..ceedf62b336 100644
--- a/jstests/core/count5.js
+++ b/jstests/core/count5.js
@@ -14,7 +14,7 @@ q = {
 assert.eq(50, t.find(q).count(), "A");
 assert.eq(50, t.find(q).itcount(), "B");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 assert.eq(50, t.find(q).count(), "C");
 assert.eq(50, t.find(q).itcount(), "D");
diff --git a/jstests/core/count6.js b/jstests/core/count6.js
index 46fb428ef97..78735c89c26 100644
--- a/jstests/core/count6.js
+++ b/jstests/core/count6.js
@@ -6,7 +6,7 @@ t = db.jstests_count6;
 
 function checkCountForObject(obj) {
     t.drop();
-    t.ensureIndex({b: 1, a: 1});
+    t.createIndex({b: 1, a: 1});
 
     function checkCounts(query, expected) {
         assert.eq(expected, t.count(query), "A1");
diff --git a/jstests/core/count7.js b/jstests/core/count7.js
index 95417e241de..443134474a8 100644
--- a/jstests/core/count7.js
+++ b/jstests/core/count7.js
@@ -5,7 +5,7 @@
 t = db.jstests_count7;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: 'algebra'});
 t.save({a: 'apple'});
 t.save({a: 'azores'});
diff --git a/jstests/core/count9.js b/jstests/core/count9.js
index 517322a9310..062f099e513 100644
--- a/jstests/core/count9.js
+++ b/jstests/core/count9.js
@@ -3,7 +3,7 @@
 t = db.jstests_count9;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 t.save({a: ['a', 'b', 'a']});
 assert.eq(1, t.count({a: 'a'}));
@@ -12,7 +12,7 @@ t.save({a: ['a', 'b', 'a']});
 assert.eq(2, t.count({a: 'a'}));
 
 t.drop();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 
 t.save({a: ['a', 'b', 'a'], b: 'r'});
 assert.eq(1, t.count({a: 'a', b: 'r'}));
@@ -23,6 +23,6 @@ assert.eq(2, t.count({a: 'a', b: 'r'}));
 assert.eq(2, t.count({a: 'a'}));
 
 t.drop();
-t.ensureIndex({'a.b': 1, 'a.c': 1});
+t.createIndex({'a.b': 1, 'a.c': 1});
 t.save({a: [{b: 'b', c: 'c'}, {b: 'b', c: 'c'}]});
 assert.eq(1, t.count({'a.b': 'b', 'a.c': 'c'}));
diff --git a/jstests/core/count_hint.js b/jstests/core/count_hint.js
index 21c7a37b87d..5ba9514de87 100644
--- a/jstests/core/count_hint.js
+++ b/jstests/core/count_hint.js
@@ -18,7 +18,7 @@ assert.commandWorked(coll.insert({i: 2}));
 
 assert.eq(2, coll.find().count());
 
-assert.commandWorked(coll.ensureIndex({i: 1}));
+assert.commandWorked(coll.createIndex({i: 1}));
 
 assert.eq(2, coll.find().hint("i_1").count());
 assert.eq(2, coll.find().hint({i: 1}).count());
@@ -30,7 +30,7 @@ assert.eq(2, coll.find().hint("_id_").count());
 assert.eq(2, coll.find().hint({_id: 1}).count());
 
 // Create a sparse index which should have no entries.
-assert.commandWorked(coll.ensureIndex({x: 1}, {sparse: true}));
+assert.commandWorked(coll.createIndex({x: 1}, {sparse: true}));
 
 // A hint should be respected, even if it results in the wrong answer.
 assert.eq(0, coll.find().hint("x_1").count());
diff --git a/jstests/core/countb.js b/jstests/core/countb.js
index bd6f9507fd2..869825b25a1 100644
--- a/jstests/core/countb.js
+++ b/jstests/core/countb.js
@@ -7,7 +7,7 @@
 t = db.jstests_countb;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: ['a', 'b']});
 assert.eq(0, t.find({a: {$in: ['a'], $gt: 'b'}}).count());
 assert.eq(0, t.find({$and: [{a: 'a'}, {a: {$gt: 'b'}}]}).count());
diff --git a/jstests/core/countc.js b/jstests/core/countc.js
index 876129c573f..5f0d31b769c 100644
--- a/jstests/core/countc.js
+++ b/jstests/core/countc.js
@@ -14,7 +14,7 @@ t.drop();
 
 // Match a subset of inserted values within a $in operator.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 // Save 'a' values 0, 0.5, 1.5, 2.5 ... 97.5, 98.5, 99.
 t.save({a: 0});
 t.save({a: 99});
@@ -31,7 +31,7 @@ assert.eq(2, t.count({a: {$in: vals}}));
 
 // Match 'a' values within upper and lower limits.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: [1, 2]});  // Will match because 'a' is in range.
 t.save({a: 9});       // Will not match because 'a' is not in range.
 // Only one document matches.
@@ -39,14 +39,14 @@ assert.eq(1, t.count({a: {$gt: 0, $lt: 5}}));
 
 // Match two nested fields within an array.
 t.drop();
-t.ensureIndex({'a.b': 1, 'a.c': 1});
+t.createIndex({'a.b': 1, 'a.c': 1});
 t.save({a: [{b: 2, c: 3}, {}]});
 // The document does not match because its c value is 3.
 assert.eq(0, t.count({'a.b': 2, 'a.c': 2}));
 
 // $gt:string only matches strings.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: 'a'});  // Will match.
 t.save({a: {}});   // Will not match because {} is not a string.
 // Only one document matches.
@@ -54,7 +54,7 @@ assert.eq(1, t.count({a: {$gte: ''}}));
 
 // $lte:date only matches dates.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: new Date(1)});  // Will match.
 t.save({a: true});         // Will not match because 'true' is not a date.
 // Only one document matches.
@@ -62,14 +62,14 @@ assert.eq(1, t.count({a: {$lte: new Date(1)}}));
 
 // Querying for 'undefined' triggers an error.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 assert.throws(function() {
     t.count({a: undefined});
 });
 
 // Count using a descending order index.
 t.drop();
-t.ensureIndex({a: -1});
+t.createIndex({a: -1});
 t.save({a: 1});
 t.save({a: 2});
 t.save({a: 3});
@@ -80,7 +80,7 @@ assert.eq(2, t.count({a: {$lt: 3}}));
 
 // Count using a compound index.
 t.drop();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 t.save({a: 1, b: 2});
 t.save({a: 2, b: 1});
 t.save({a: 2, b: 3});
@@ -95,7 +95,7 @@ assert.eq(1, t.count({a: 1, b: {$lt: 3}}));
 
 // Count using a compound descending order index.
 t.drop();
-t.ensureIndex({a: 1, b: -1});
+t.createIndex({a: 1, b: -1});
 t.save({a: 1, b: 2});
 t.save({a: 2, b: 1});
 t.save({a: 2, b: 3});
@@ -108,13 +108,13 @@ assert.eq(1, t.count({a: 1, b: {$lt: 3}}));
 
 // Count with a multikey value.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: [1, 2]});
 assert.eq(1, t.count({a: {$gt: 0, $lte: 2}}));
 
 // Count with a match constraint on an unindexed field.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: 1, b: 1});
 t.save({a: 1, b: 2});
 assert.eq(1, t.count({a: 1, $where: 'this.b == 1'}));
diff --git a/jstests/core/coveredIndex2.js b/jstests/core/coveredIndex2.js
index 9ec3ce529ae..41092e7d525 100644
--- a/jstests/core/coveredIndex2.js
+++ b/jstests/core/coveredIndex2.js
@@ -19,7 +19,7 @@ assert.eq(t.findOne({a: 1}).a, 1, "Cannot find right record");
 assert.eq(t.count(), 2, "Not right length");
 
 // use simple index
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 var plan = t.find({a: 1}).explain();
 assert(!isIndexOnly(db, plan.queryPlanner.winningPlan),
        "Find using covered index but all fields are returned");
diff --git a/jstests/core/coveredIndex3.js b/jstests/core/coveredIndex3.js
index a054840b6df..8b15b40e862 100644
--- a/jstests/core/coveredIndex3.js
+++ b/jstests/core/coveredIndex3.js
@@ -30,7 +30,7 @@ if (0) {  // SERVER-4975
 
         for (i = 0; i < 30; ++i) {
             t.drop();
-            t.ensureIndex({a: 1});
+            t.createIndex({a: 1});
 
             for (j = 0; j < 1000; ++j) {
                 t.save({a: j});
diff --git a/jstests/core/coveredIndex4.js b/jstests/core/coveredIndex4.js
index 125cf22da3a..e62162d1685 100644
--- a/jstests/core/coveredIndex4.js
+++ b/jstests/core/coveredIndex4.js
@@ -9,8 +9,8 @@
 t = db.jstests_coveredIndex4;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 orClause = [];
 for (i = 0; i < 200; ++i) {
diff --git a/jstests/core/covered_index_compound_1.js b/jstests/core/covered_index_compound_1.js
index 2f2d45adabd..a43a4f70ec5 100644
--- a/jstests/core/covered_index_compound_1.js
+++ b/jstests/core/covered_index_compound_1.js
@@ -16,7 +16,7 @@ coll.drop();
 for (i = 0; i < 100; i++) {
     coll.insert({a: i, b: "strvar_" + (i % 13), c: NumberInt(i % 10)});
 }
-coll.ensureIndex({a: 1, b: -1, c: 1});
+coll.createIndex({a: 1, b: -1, c: 1});
 
 // Test equality - all indexed fields queried and projected
 var plan = coll.find({a: 10, b: "strvar_10", c: 0}, {a: 1, b: 1, c: 1, _id: 0})
diff --git a/jstests/core/covered_index_negative_1.js b/jstests/core/covered_index_negative_1.js
index 4028b1159b2..06d4119ffe4 100644
--- a/jstests/core/covered_index_negative_1.js
+++ b/jstests/core/covered_index_negative_1.js
@@ -16,10 +16,10 @@ for (i = 0; i < 100; i++) {
     coll.insert(
         {a: i, b: "strvar_" + (i % 13), c: NumberInt(i % 10), d: i * 10, e: [i, i % 10], f: i});
 }
-coll.ensureIndex({a: 1, b: -1, c: 1});
-coll.ensureIndex({e: 1});
-coll.ensureIndex({d: 1});
-coll.ensureIndex({f: "hashed"});
+coll.createIndex({a: 1, b: -1, c: 1});
+coll.createIndex({e: 1});
+coll.createIndex({d: 1});
+coll.createIndex({f: "hashed"});
 
 // Test no projection
 var plan =
diff --git a/jstests/core/covered_index_simple_1.js b/jstests/core/covered_index_simple_1.js
index c49e5a2bc8e..ce8f1978a89 100644
--- a/jstests/core/covered_index_simple_1.js
+++ b/jstests/core/covered_index_simple_1.js
@@ -25,7 +25,7 @@ for (i = 0; i < 5; i++) {
 coll.insert({foo: "string"});
 coll.insert({foo: {bar: 1}});
 coll.insert({foo: null});
-coll.ensureIndex({foo: 1});
+coll.createIndex({foo: 1});
 
 // Test equality with int value
 var plan = coll.find({foo: 1}, {foo: 1, _id: 0}).hint({foo: 1}).explain("executionStats");
diff --git a/jstests/core/covered_index_simple_2.js b/jstests/core/covered_index_simple_2.js
index 67548ed8c06..066bf1bae4c 100644
--- a/jstests/core/covered_index_simple_2.js
+++ b/jstests/core/covered_index_simple_2.js
@@ -19,7 +19,7 @@ for (i = 0; i < 10; i++) {
 coll.insert({foo: "string"});
 coll.insert({foo: {bar: 1}});
 coll.insert({foo: null});
-coll.ensureIndex({foo: 1}, {unique: true});
+coll.createIndex({foo: 1}, {unique: true});
 
 // Test equality with int value
 var plan = coll.find({foo: 1}, {foo: 1, _id: 0}).hint({foo: 1}).explain("executionStats");
diff --git a/jstests/core/covered_index_simple_3.js b/jstests/core/covered_index_simple_3.js
index 5e654475252..c0e62a9243d 100644
--- a/jstests/core/covered_index_simple_3.js
+++ b/jstests/core/covered_index_simple_3.js
@@ -22,7 +22,7 @@ for (i = 0; i < 5; i++) {
 coll.insert({foo: "string"});
 coll.insert({foo: {bar: 1}});
 coll.insert({foo: null});
-coll.ensureIndex({foo: 1}, {sparse: true, unique: true});
+coll.createIndex({foo: 1}, {sparse: true, unique: true});
 
 // Test equality with int value
 var plan = coll.find({foo: 1}, {foo: 1, _id: 0}).hint({foo: 1}).explain("executionStats");
@@ -85,7 +85,7 @@ assert.eq(0,
 
 // Check that $nin can be covered.
 coll.dropIndexes();
-coll.ensureIndex({bar: 1});
+coll.createIndex({bar: 1});
 var plan =
     coll.find({bar: {$nin: [5, 8]}}, {bar: 1, _id: 0}).hint({bar: 1}).explain("executionStats");
 assert(isIndexOnly(db, plan.queryPlanner.winningPlan),
diff --git a/jstests/core/covered_index_sort_1.js b/jstests/core/covered_index_sort_1.js
index 4b8cea2e825..526ddfbaa42 100644
--- a/jstests/core/covered_index_sort_1.js
+++ b/jstests/core/covered_index_sort_1.js
@@ -25,7 +25,7 @@ for (i = 0; i < 5; i++) {
 coll.insert({foo: "1"});
 coll.insert({foo: {bar: 1}});
 coll.insert({foo: null});
-coll.ensureIndex({foo: 1});
+coll.createIndex({foo: 1});
 
 // Test no query and sort ascending
 var plan = coll.find({}, {foo: 1, _id: 0}).sort({foo: 1}).hint({foo: 1}).explain("executionStats");
diff --git a/jstests/core/covered_index_sort_3.js b/jstests/core/covered_index_sort_3.js
index 1107e0584dc..0e9b1ea30ff 100644
--- a/jstests/core/covered_index_sort_3.js
+++ b/jstests/core/covered_index_sort_3.js
@@ -17,7 +17,7 @@ for (i = 0; i < 100; i++) {
     coll.insert({a: i, b: "strvar_" + (i % 13), c: NumberInt(i % 10)});
 }
 
-coll.ensureIndex({a: 1, b: -1, c: 1});
+coll.createIndex({a: 1, b: -1, c: 1});
 
 // Test no query, sort on all fields in index order
 var plan = coll.find({}, {b: 1, c: 1, _id: 0})
diff --git a/jstests/core/create_index_helper_validation.js b/jstests/core/create_index_helper_validation.js
index 805c567316d..1b11a50c6ca 100644
--- a/jstests/core/create_index_helper_validation.js
+++ b/jstests/core/create_index_helper_validation.js
@@ -20,7 +20,7 @@ assert.throws(() => coll.createIndex(
                   {background: true},
                   {unique: true}));
 
-assert.throws(() => coll.ensureIndex(
+assert.throws(() => coll.createIndex(
                   /* keys */ {a: 1},
                   /* options */ {},
                   /* commitQuorum */ "majority",
diff --git a/jstests/core/crud_api.js b/jstests/core/crud_api.js
index 4b37300e9b1..9eb09ab6436 100644
--- a/jstests/core/crud_api.js
+++ b/jstests/core/crud_api.js
@@ -700,7 +700,7 @@ var crudAPISpecTests = function crudAPISpecTests() {
 
     // Drop collection
     coll.drop();
-    coll.ensureIndex({a: 1}, {unique: true});
+    coll.createIndex({a: 1}, {unique: true});
 
     // Should throw duplicate key error
     assert.throws(function() {
diff --git a/jstests/core/cursor3.js b/jstests/core/cursor3.js
index 1a7e0dfcc7e..f416ec47931 100644
--- a/jstests/core/cursor3.js
+++ b/jstests/core/cursor3.js
@@ -23,7 +23,7 @@ t.save({a: 0});
 t.save({a: 1});
 t.save({a: 2});
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 checkResults([1], t.find({a: 1}).sort({a: 1}).hint({a: 1}), testNum++);
 checkResults([1], t.find({a: 1}).sort({a: -1}).hint({a: 1}), testNum++);
diff --git a/jstests/core/cursor4.js b/jstests/core/cursor4.js
index dd7875d0836..d0440d329f1 100644
--- a/jstests/core/cursor4.js
+++ b/jstests/core/cursor4.js
@@ -15,7 +15,7 @@ function testConstrainedFindMultiFieldSorting(db) {
     entries = [{a: 0, b: 0}, {a: 0, b: 1}, {a: 1, b: 1}, {a: 1, b: 1}, {a: 2, b: 0}];
     for (i = 0; i < entries.length; ++i)
         r.save(entries[i]);
-    r.ensureIndex({a: 1, b: 1});
+    r.createIndex({a: 1, b: 1});
     reverseEntries = entries.slice();
     reverseEntries.reverse();
 
diff --git a/jstests/core/cursor5.js b/jstests/core/cursor5.js
index 0232b92e4cc..aab03473255 100644
--- a/jstests/core/cursor5.js
+++ b/jstests/core/cursor5.js
@@ -26,7 +26,7 @@ function testBoundsWithSubobjectIndexes(db) {
         r.save(z[i]);
     idx = {"a.d": 1, a: 1, e: -1};
     rIdx = {"a.d": -1, a: -1, e: 1};
-    r.ensureIndex(idx);
+    r.createIndex(idx);
 
     checkResults([z[0], z[4], z[2]], r.find({e: 4}).sort(idx).hint(idx));
     checkResults([z[1], z[3]], r.find({e: {$gt: 4}, "a.b": 1}).sort(idx).hint(idx));
diff --git a/jstests/core/cursor6.js b/jstests/core/cursor6.js
index d2c56c00e75..7c8daa1bfcb 100644
--- a/jstests/core/cursor6.js
+++ b/jstests/core/cursor6.js
@@ -60,7 +60,7 @@ z = [{a: 1, b: 1}, {a: 1, b: 2}, {a: 2, b: 1}, {a: 2, b: 2}];
 for (i = 0; i < z.length; ++i)
     r.save(z[i]);
 
-r.ensureIndex({a: 1, b: -1});
+r.createIndex({a: 1, b: -1});
 
 check(false);
 check(true);
diff --git a/jstests/core/cursor7.js b/jstests/core/cursor7.js
index 7807dbe22f5..4a21c420274 100644
--- a/jstests/core/cursor7.js
+++ b/jstests/core/cursor7.js
@@ -17,7 +17,7 @@ function testMultipleInequalities(db) {
         r.save(z[i]);
     idx = {a: 1, b: 1};
     rIdx = {a: -1, b: -1};
-    r.ensureIndex(idx);
+    r.createIndex(idx);
 
     checkResults([z[2], z[3]], r.find({a: {$gt: 3}}).sort(idx).hint(idx));
     checkResults([z[2]], r.find({a: {$gt: 3, $lt: 7}}).sort(idx).hint(idx));
diff --git a/jstests/core/date2.js b/jstests/core/date2.js
index 15993815b14..a398058d771 100644
--- a/jstests/core/date2.js
+++ b/jstests/core/date2.js
@@ -3,7 +3,7 @@
 t = db.jstests_date2;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 var obj = {a: new Timestamp(0, 1)};  // in old versions this was == to new Date(1)
 t.save(obj);
diff --git a/jstests/core/date3.js b/jstests/core/date3.js
index 80279a9559c..e3eaea620ec 100644
--- a/jstests/core/date3.js
+++ b/jstests/core/date3.js
@@ -29,5 +29,5 @@ function test() {
 }
 
 test();
-t.ensureIndex({d: 1});
+t.createIndex({d: 1});
 test();
diff --git a/jstests/core/distinct3.js b/jstests/core/distinct3.js
index 654cd8e352a..6a67635500d 100644
--- a/jstests/core/distinct3.js
+++ b/jstests/core/distinct3.js
@@ -10,8 +10,8 @@
 t = db.jstests_distinct3;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 var bulk = t.initializeUnorderedBulkOp();
 for (i = 0; i < 50; ++i) {
diff --git a/jstests/core/distinct_array1.js b/jstests/core/distinct_array1.js
index 2d3a96a6af6..cb82c25bbff 100644
--- a/jstests/core/distinct_array1.js
+++ b/jstests/core/distinct_array1.js
@@ -19,7 +19,7 @@ res = t.distinct("a.1").sort();
 assert.eq("2,3,4", res.toString());
 
 // With index.
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 res = t.distinct("a").sort();
 assert.eq("1,2,3,4,5,9", res.toString());
 
@@ -51,7 +51,7 @@ res = t.distinct("a.1.b").sort();
 assert.eq("d,e,f", res.toString());
 
 // With index.
-t.ensureIndex({"a.b": 1});
+t.createIndex({"a.b": 1});
 res = t.distinct("a.b");
 res.sort();
 // TODO SERVER-14832 The presence of an index may change results, but only if the index is not
@@ -85,7 +85,7 @@ res = t.distinct("_id.a.1").sort();
 assert.eq("2,3,4", res.toString());
 
 // With index.
-t.ensureIndex({"_id.a": 1});
+t.createIndex({"_id.a": 1});
 res = t.distinct("_id.a").sort();
 // TODO SERVER-14832: distinct() may incorrectly return null in presence of index.
 assert.eq([1, 2, 3, 4, 5, 9, null], res);
diff --git a/jstests/core/distinct_index2.js b/jstests/core/distinct_index2.js
index d1b72565102..1f552102059 100644
--- a/jstests/core/distinct_index2.js
+++ b/jstests/core/distinct_index2.js
@@ -1,8 +1,8 @@
 t = db.distinct_index2;
 t.drop();
 
-t.ensureIndex({a: 1, b: 1});
-t.ensureIndex({c: 1});
+t.createIndex({a: 1, b: 1});
+t.createIndex({c: 1});
 
 // Uniformly distributed dataset.
 // If we use a randomly generated dataset, we might not
@@ -37,5 +37,5 @@ check("c");
 
 // hashed index should produce same results.
 t.dropIndexes();
-t.ensureIndex({a: "hashed"});
+t.createIndex({a: "hashed"});
 check("a");
diff --git a/jstests/core/drop.js b/jstests/core/drop.js
index ea395660a5f..769a8cd348c 100644
--- a/jstests/core/drop.js
+++ b/jstests/core/drop.js
@@ -12,12 +12,12 @@ assert(!res.ok, tojson(res));
 assert.eq(0, coll.getIndexes().length, "A");
 coll.save({});
 assert.eq(1, coll.getIndexes().length, "B");
-coll.ensureIndex({a: 1});
+coll.createIndex({a: 1});
 assert.eq(2, coll.getIndexes().length, "C");
 assert.commandWorked(db.runCommand({drop: coll.getName()}));
 assert.eq(0, coll.getIndexes().length, "D");
 
-coll.ensureIndex({a: 1});
+coll.createIndex({a: 1});
 assert.eq(2, coll.getIndexes().length, "E");
 assert.commandWorked(db.runCommand({dropIndexes: coll.getName(), index: "*"}), "drop indexes A");
 assert.eq(1, coll.getIndexes().length, "G");
diff --git a/jstests/core/drop_index.js b/jstests/core/drop_index.js
index 60dbec0e3ea..e808b1f7829 100644
--- a/jstests/core/drop_index.js
+++ b/jstests/core/drop_index.js
@@ -57,7 +57,7 @@ assert.commandFailedWithCode(t.dropIndex({_id: 1}), ErrorCodes.InvalidOptions);
 
 // Ensure you can recreate indexes, even if you don't use dropIndex method.
 // Prior to SERVER-7168, the shell used to cache names of indexes created using
-// Collection.ensureIndex().
+// Collection.createIndex().
 assert.commandWorked(t.createIndex({a: 1}));
 assertIndexes(['a_1', 'c_1', 'd_1', 'e_1'], 'recreating {a: 1}');
 
diff --git a/jstests/core/dropdb_race.js b/jstests/core/dropdb_race.js
index 6bcd334e7ab..8f1356db1d6 100644
--- a/jstests/core/dropdb_race.js
+++ b/jstests/core/dropdb_race.js
@@ -25,7 +25,7 @@ for (var pass = 0; pass < 100; pass++) {
     }
     t.insert({x: 1});
     t.insert({x: 3});
-    t.ensureIndex({x: 1});
+    t.createIndex({x: 1});
     sleep(s);
     if (pass % 13 == 0)
         t.drop();
diff --git a/jstests/core/exists.js b/jstests/core/exists.js
index e0ba49fabd8..b85d80c36a7 100644
--- a/jstests/core/exists.js
+++ b/jstests/core/exists.js
@@ -36,10 +36,10 @@ function dotest(n) {
 }
 
 dotest("before index");
-t.ensureIndex({"a": 1});
-t.ensureIndex({"a.b": 1});
-t.ensureIndex({"a.b.c": 1});
-t.ensureIndex({"a.b.c.d": 1});
+t.createIndex({"a": 1});
+t.createIndex({"a.b": 1});
+t.createIndex({"a.b.c": 1});
+t.createIndex({"a.b.c.d": 1});
 dotest("after index");
 assert.eq(1, t.find({a: {$exists: false}}).hint({a: 1}).itcount());
 
diff --git a/jstests/core/exists2.js b/jstests/core/exists2.js
index 3b4580cd310..0764d859c3b 100644
--- a/jstests/core/exists2.js
+++ b/jstests/core/exists2.js
@@ -9,6 +9,6 @@ assert.eq(2, t.find({a: 1, b: 1}).itcount(), "A2");
 assert.eq(1, t.find({a: 1, b: 1, c: {"$exists": true}}).itcount(), "A3");
 assert.eq(1, t.find({a: 1, b: 1, c: {"$exists": false}}).itcount(), "A4");
 
-t.ensureIndex({a: 1, b: 1, c: 1});
+t.createIndex({a: 1, b: 1, c: 1});
 assert.eq(1, t.find({a: 1, b: 1, c: {"$exists": true}}).itcount(), "B1");
 assert.eq(1, t.find({a: 1, b: 1, c: {"$exists": false}}).itcount(), "B2");
diff --git a/jstests/core/exists3.js b/jstests/core/exists3.js
index e4ce03437bb..510d63c3752 100644
--- a/jstests/core/exists3.js
+++ b/jstests/core/exists3.js
@@ -11,7 +11,7 @@ assert.eq(1, t.find({c: {$exists: false}}).itcount());
 assert.eq(1, t.find({c: {$exists: false}}).sort({c: -1}).itcount());
 
 // now we have an index on the sort key
-t.ensureIndex({c: -1});
+t.createIndex({c: -1});
 
 assert.eq(1, t.find({c: {$exists: false}}).sort({c: -1}).itcount());
 assert.eq(1, t.find({c: {$exists: false}}).itcount());
diff --git a/jstests/core/exists4.js b/jstests/core/exists4.js
index 2979a60f276..a533ca53e9c 100644
--- a/jstests/core/exists4.js
+++ b/jstests/core/exists4.js
@@ -3,7 +3,7 @@
 t = db.jstests_exists4;
 t.drop();
 
-t.ensureIndex({date: -1, country_code: 1, user_id: 1}, {unique: 1, background: 1});
+t.createIndex({date: -1, country_code: 1, user_id: 1}, {unique: 1, background: 1});
 t.insert({date: new Date("08/27/2010"), tot_visit: 100});
 t.insert({date: new Date("08/27/2010"), country_code: "IT", tot_visit: 77});
 t.insert({date: new Date("08/27/2010"), country_code: "ES", tot_visit: 23});
diff --git a/jstests/core/exists6.js b/jstests/core/exists6.js
index 67ab7e5345d..736574db895 100644
--- a/jstests/core/exists6.js
+++ b/jstests/core/exists6.js
@@ -3,7 +3,7 @@
 t = db.jstests_exists6;
 t.drop();
 
-t.ensureIndex({b: 1});
+t.createIndex({b: 1});
 t.save({});
 t.save({b: 1});
 t.save({b: null});
@@ -14,7 +14,7 @@ assert.eq(1, t.find({b: {$exists: false}}).itcount());
 assert.eq(1, t.find({b: {$not: {$exists: true}}}).itcount());
 
 // Now check existence of second compound field.
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 t.save({a: 1});
 t.save({a: 1, b: 1});
 t.save({a: 1, b: null});
diff --git a/jstests/core/exists7.js b/jstests/core/exists7.js
index 74ea4e9719c..6ca55a42286 100644
--- a/jstests/core/exists7.js
+++ b/jstests/core/exists7.js
@@ -18,5 +18,5 @@ function testIntegerExistsSpec() {
 }
 
 testIntegerExistsSpec();
-t.ensureIndex({b: 1});
+t.createIndex({b: 1});
 testIntegerExistsSpec();
diff --git a/jstests/core/exists9.js b/jstests/core/exists9.js
index 444bcf731a1..3b245cd4188 100644
--- a/jstests/core/exists9.js
+++ b/jstests/core/exists9.js
@@ -12,7 +12,7 @@ assert.eq(1, t.count({'a.b': {$exists: false}}));
 assert.eq(0, t.count({'a.b': {$exists: true}}));
 
 // With index.
-t.ensureIndex({'a.b': 1});
+t.createIndex({'a.b': 1});
 assert.eq(1, t.find({'a.b': {$exists: false}}).hint({'a.b': 1}).itcount());
 assert.eq(0, t.find({'a.b': {$exists: true}}).hint({'a.b': 1}).itcount());
 
@@ -25,7 +25,7 @@ assert.eq(1, t.count({a: {$exists: true}}));
 assert.eq(1, t.count({a: {$exists: false}}));
 
 // With index.
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 assert.eq(1, t.find({a: {$exists: true}}).hint({a: 1}).itcount());
 assert.eq(1, t.find({a: {$exists: false}}).hint({a: 1}).itcount());
 
@@ -38,6 +38,6 @@ assert.eq(1, t.count({'a.0': {$exists: true}}));
 assert.eq(1, t.count({'a.0': {$exists: false}}));
 
 // With index.
-t.ensureIndex({'a.0': 1});
+t.createIndex({'a.0': 1});
 assert.eq(1, t.find({'a.0': {$exists: true}}).hint({'a.0': 1}).itcount());
 assert.eq(1, t.find({'a.0': {$exists: false}}).hint({'a.0': 1}).itcount());
diff --git a/jstests/core/existsa.js b/jstests/core/existsa.js
index d1079310d71..2b5f70dd77f 100644
--- a/jstests/core/existsa.js
+++ b/jstests/core/existsa.js
@@ -19,7 +19,7 @@ function setIndex(_indexKeyField) {
     indexKeyField = _indexKeyField;
     indexKeySpec = {};
     indexKeySpec[indexKeyField] = 1;
-    coll.ensureIndex(indexKeySpec, {sparse: true});
+    coll.createIndex(indexKeySpec, {sparse: true});
 }
 setIndex('a');
 
@@ -106,6 +106,6 @@ assertExistsUnindexed({'a.b': {$elemMatch: {$gt: 0, $not: {$exists: false}}}}, 1
 // A non sparse index will not be disallowed.
 coll.drop();
 assert.commandWorked(coll.insert({}));
-coll.ensureIndex({a: 1});
+coll.createIndex({a: 1});
 assert.eq(1, coll.find({a: {$exists: false}}).itcount());
 })();
diff --git a/jstests/core/existsb.js b/jstests/core/existsb.js
index d46266cdd16..64ee3cf9a88 100644
--- a/jstests/core/existsb.js
+++ b/jstests/core/existsb.js
@@ -57,20 +57,20 @@ function checkExistsNull() {
 checkExistsNull();
 
 // try with a standard index
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 checkExistsNull();
 
 // try with a sparse index
 t.dropIndexes();
-t.ensureIndex({a: 1}, {sparse: true});
+t.createIndex({a: 1}, {sparse: true});
 checkExistsNull();
 
 // try with a compound index
 t.dropIndexes();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 checkExistsNull();
 
 // try with sparse compound index
 t.dropIndexes();
-t.ensureIndex({a: 1, b: 1}, {sparse: true});
+t.createIndex({a: 1, b: 1}, {sparse: true});
 checkExistsNull();
diff --git a/jstests/core/explain1.js b/jstests/core/explain1.js
index 09891f214dd..8450335159d 100644
--- a/jstests/core/explain1.js
+++ b/jstests/core/explain1.js
@@ -19,7 +19,7 @@ assert.eq(49, t.find(q).count(), "A");
 assert.eq(49, t.find(q).itcount(), "B");
 assert.eq(20, t.find(q).limit(20).itcount(), "C");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 assert.eq(49, t.find(q).count(), "D");
 assert.eq(49, t.find(q).itcount(), "E");
diff --git a/jstests/core/explain4.js b/jstests/core/explain4.js
index 06c7bf0b359..df0d98382e0 100644
--- a/jstests/core/explain4.js
+++ b/jstests/core/explain4.js
@@ -6,7 +6,7 @@
 t = db.jstests_explain4;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 for (i = 0; i < 10; ++i) {
     t.save({a: i, b: 0});
diff --git a/jstests/core/explain5.js b/jstests/core/explain5.js
index 5bae866e096..50648cd8817 100644
--- a/jstests/core/explain5.js
+++ b/jstests/core/explain5.js
@@ -7,8 +7,8 @@
 t = db.jstests_explain5;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 for (i = 0; i < 1000; ++i) {
     t.save({a: i, b: i % 3});
diff --git a/jstests/core/explain6.js b/jstests/core/explain6.js
index dbbb767531c..f36640ce567 100644
--- a/jstests/core/explain6.js
+++ b/jstests/core/explain6.js
@@ -10,8 +10,8 @@
 t = db.jstests_explain6;
 t.drop();
 
-t.ensureIndex({a: 1, b: 1});
-t.ensureIndex({b: 1, a: 1});
+t.createIndex({a: 1, b: 1});
+t.createIndex({b: 1, a: 1});
 
 t.save({a: 0, b: 1});
 t.save({a: 1, b: 0});
diff --git a/jstests/core/explain_count.js b/jstests/core/explain_count.js
index 883f8b84ac7..8dc0854ab15 100644
--- a/jstests/core/explain_count.js
+++ b/jstests/core/explain_count.js
@@ -99,7 +99,7 @@ assertExplainCount({explainResults: explain, expectedCount: 0});
 // Now add a bit of data to the collection.
 // On sharded clusters, we'll want the shard key to be indexed, so we make _id part of the index.
 // This means counts will not have to fetch from the document in order to get the shard key.
-t.ensureIndex({a: 1, _id: 1});
+t.createIndex({a: 1, _id: 1});
 for (var i = 0; i < 10; i++) {
     t.insert({_id: i, a: 1});
 }
diff --git a/jstests/core/explain_delete.js b/jstests/core/explain_delete.js
index 1863979faa5..44a67ea21ca 100644
--- a/jstests/core/explain_delete.js
+++ b/jstests/core/explain_delete.js
@@ -43,7 +43,7 @@ explain = db.runCommand({explain: {delete: collName, deletes: [{q: {a: 1}, limit
 checkNWouldDelete(explain, 0);
 
 // Add an index but no data, and check that the explain still works.
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 explain = db.runCommand({explain: {delete: collName, deletes: [{q: {a: 1}, limit: 0}]}});
 checkNWouldDelete(explain, 0);
 
diff --git a/jstests/core/explain_execution_error.js b/jstests/core/explain_execution_error.js
index d2240452573..4515a050edc 100644
--- a/jstests/core/explain_execution_error.js
+++ b/jstests/core/explain_execution_error.js
@@ -117,8 +117,8 @@ assertExecError(result);
 
 // Now we introduce two indices. One provides the requested sort order, and
 // the other does not.
-t.ensureIndex({b: 1});
-t.ensureIndex({c: 1});
+t.createIndex({b: 1});
+t.createIndex({c: 1});
 
 // The query should no longer fail with a memory limit error because the planner can obtain
 // the sort by scanning an index.
diff --git a/jstests/core/explain_find.js b/jstests/core/explain_find.js
index fcf2e35053c..c42d59d7671 100644
--- a/jstests/core/explain_find.js
+++ b/jstests/core/explain_find.js
@@ -10,7 +10,7 @@ var collName = "jstests_explain_find";
 var t = db[collName];
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 for (var i = 0; i < 10; i++) {
     t.insert({_id: i, a: i});
diff --git a/jstests/core/explain_large_bounds.js b/jstests/core/explain_large_bounds.js
index 1ff7307e7d9..1ca27f9a8ef 100644
--- a/jstests/core/explain_large_bounds.js
+++ b/jstests/core/explain_large_bounds.js
@@ -8,7 +8,7 @@
 const coll = db.jstests_explain_large_bounds;
 coll.drop();
 
-coll.ensureIndex({a: 1});
+coll.createIndex({a: 1});
 
 let inClause = [];
 for (let i = 0; i < 1000000; i++) {
diff --git a/jstests/core/explain_multi_plan.js b/jstests/core/explain_multi_plan.js
index dc8f153e6cb..845438af91e 100644
--- a/jstests/core/explain_multi_plan.js
+++ b/jstests/core/explain_multi_plan.js
@@ -16,8 +16,8 @@ var coll = db.explainMultiPlan;
 coll.drop();
 
 // Create indices to ensure there are multiple plans available.
-assert.commandWorked(coll.ensureIndex({a: 1, b: 1}));
-assert.commandWorked(coll.ensureIndex({a: 1, b: -1}));
+assert.commandWorked(coll.createIndex({a: 1, b: 1}));
+assert.commandWorked(coll.createIndex({a: 1, b: -1}));
 
 // Insert some data to work with.
 var bulk = coll.initializeOrderedBulkOp();
diff --git a/jstests/core/explain_shell_helpers.js b/jstests/core/explain_shell_helpers.js
index 1a66a032143..cad5fec9141 100644
--- a/jstests/core/explain_shell_helpers.js
+++ b/jstests/core/explain_shell_helpers.js
@@ -22,7 +22,7 @@ load("jstests/libs/analyze_plan.js");
 var explain;
 var stage;
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 for (var i = 0; i < 10; i++) {
     t.insert({_id: i, a: i, b: 1});
 }
@@ -267,7 +267,7 @@ assert(planHasStage(db, explain.queryPlanner.winningPlan, "COUNT"));
 assert(planHasStage(db, explain.queryPlanner.winningPlan, "COUNT_SCAN"));
 
 // Explainable count with hint.
-assert.commandWorked(t.ensureIndex({c: 1}, {sparse: true}));
+assert.commandWorked(t.createIndex({c: 1}, {sparse: true}));
 explain = t.explain().count({c: {$exists: false}}, {hint: "c_1"});
 assert.commandWorked(explain);
 assert(planHasStage(db, explain.queryPlanner.winningPlan, "IXSCAN"));
diff --git a/jstests/core/expr.js b/jstests/core/expr.js
index 1a23ac00d8b..a6861a4d2cf 100644
--- a/jstests/core/expr.js
+++ b/jstests/core/expr.js
@@ -190,7 +190,7 @@ if (db.getMongo().writeMode() === "commands") {
 
 coll.drop();
 assert.commandWorked(coll.insert({geo: {type: "Point", coordinates: [0, 0]}, a: 0}));
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 assert.eq(1,
           coll.aggregate({
                   $geoNear: {
diff --git a/jstests/core/filemd5.js b/jstests/core/filemd5.js
index b33611c1e90..064bf323bcf 100644
--- a/jstests/core/filemd5.js
+++ b/jstests/core/filemd5.js
@@ -17,7 +17,7 @@ assert.commandWorked(db.fs.chunks.insert({files_id: 1, n: 0, data: new BinData(0
 assert.commandFailedWithCode(db.runCommand({filemd5: 1, root: "fs"}),
                              ErrorCodes.NoQueryExecutionPlans);
 
-db.fs.chunks.ensureIndex({files_id: 1, n: 1});
+db.fs.chunks.createIndex({files_id: 1, n: 1});
 assert.commandWorked(db.runCommand({filemd5: 1, root: "fs"}));
 
 assert.commandFailedWithCode(db.runCommand({filemd5: 1, root: "fs", partialOk: 1, md5state: 5}),
diff --git a/jstests/core/find6.js b/jstests/core/find6.js
index 7edf1739c78..4c7a0a9384b 100644
--- a/jstests/core/find6.js
+++ b/jstests/core/find6.js
@@ -34,7 +34,7 @@ function f() {
 
 for (var pass = 0; pass <= 1; pass++) {
     f();
-    q.ensureIndex({a: 1});
+    q.createIndex({a: 1});
 }
 
 t = db.multidim;
diff --git a/jstests/core/find_and_modify_concurrent_update.js b/jstests/core/find_and_modify_concurrent_update.js
index f1ac1282b49..dca7c547c18 100644
--- a/jstests/core/find_and_modify_concurrent_update.js
+++ b/jstests/core/find_and_modify_concurrent_update.js
@@ -19,8 +19,8 @@ for (var i = 0; i < 3; i++) {
     var t = db.find_and_modify_concurrent;
     t.drop();
 
-    assert.commandWorked(t.ensureIndex({a: 1}));
-    assert.commandWorked(t.ensureIndex({b: 1}));
+    assert.commandWorked(t.createIndex({a: 1}));
+    assert.commandWorked(t.createIndex({b: 1}));
     assert.commandWorked(t.insert({_id: 1, a: 1, b: 1}));
 
     var join =
diff --git a/jstests/core/find_dedup.js b/jstests/core/find_dedup.js
index 8c628b66734..8c0f416efb1 100644
--- a/jstests/core/find_dedup.js
+++ b/jstests/core/find_dedup.js
@@ -22,7 +22,7 @@ function checkDedup(query, idArray) {
 
 // Deduping $or
 coll.drop();
-coll.ensureIndex({a: 1, b: 1});
+coll.createIndex({a: 1, b: 1});
 assert.commandWorked(coll.insert({_id: 1, a: 1, b: 1}));
 assert.commandWorked(coll.insert({_id: 2, a: 1, b: 1}));
 assert.commandWorked(coll.insert({_id: 3, a: 2, b: 2}));
diff --git a/jstests/core/finda.js b/jstests/core/finda.js
index 0f59c4c7f3b..1525c7aaeda 100644
--- a/jstests/core/finda.js
+++ b/jstests/core/finda.js
@@ -11,7 +11,7 @@ t.drop();
 numDocs = 200;
 
 function clearQueryPlanCache() {
-    t.ensureIndex({c: 1});
+    t.createIndex({c: 1});
     t.dropIndex({c: 1});
 }
 
@@ -92,7 +92,7 @@ function queryWithPlanTypes(withDups) {
     } else {
         t.save({_id: 0, a: 0, b: 0});
     }
-    t.ensureIndex({a: 1, _id: 1});  // Include _id for a covered index projection.
+    t.createIndex({a: 1, _id: 1});  // Include _id for a covered index projection.
 
     // All plans in order.
     checkCursorWithBatchSize({a: {$gte: 0}}, null, 150, 150);
diff --git a/jstests/core/fts2.js b/jstests/core/fts2.js
index 77b6fe25bd5..7629d313b00 100644
--- a/jstests/core/fts2.js
+++ b/jstests/core/fts2.js
@@ -12,7 +12,7 @@ t.drop();
 t.save({_id: 1, x: "az b x", y: "c d m", z: 1});
 t.save({_id: 2, x: "c d y", y: "az b n", z: 2});
 
-t.ensureIndex({x: "text"}, {weights: {x: 10, y: 1}});
+t.createIndex({x: "text"}, {weights: {x: 10, y: 1}});
 
 assert.eq([1, 2], queryIDS(t, "az"), "A1");
 assert.eq([2, 1], queryIDS(t, "d"), "A2");
diff --git a/jstests/core/fts3.js b/jstests/core/fts3.js
index 6a4c813744a..32aa3fb002a 100644
--- a/jstests/core/fts3.js
+++ b/jstests/core/fts3.js
@@ -12,7 +12,7 @@ t.drop();
 t.save({_id: 1, x: "az b x", y: "c d m", z: 1});
 t.save({_id: 2, x: "c d y", y: "az b n", z: 2});
 
-t.ensureIndex({x: "text", z: 1}, {weights: {x: 10, y: 1}});
+t.createIndex({x: "text", z: 1}, {weights: {x: 10, y: 1}});
 
 assert.eq([1, 2], queryIDS(t, "az"), "A1");
 assert.eq([2, 1], queryIDS(t, "d"), "A2");
diff --git a/jstests/core/fts4.js b/jstests/core/fts4.js
index 16f88a7a760..ea8055eeb11 100644
--- a/jstests/core/fts4.js
+++ b/jstests/core/fts4.js
@@ -12,7 +12,7 @@ t.drop();
 t.save({_id: 1, x: ["az", "b", "x"], y: ["c", "d", "m"], z: 1});
 t.save({_id: 2, x: ["c", "d", "y"], y: ["az", "b", "n"], z: 2});
 
-t.ensureIndex({y: "text", z: 1}, {weights: {x: 10}});
+t.createIndex({y: "text", z: 1}, {weights: {x: 10}});
 
 assert.eq([1, 2], queryIDS(t, "az"), "A1");
 assert.eq([2, 1], queryIDS(t, "d"), "A2");
diff --git a/jstests/core/fts5.js b/jstests/core/fts5.js
index 99cd6ce84bb..aa689a46ed9 100644
--- a/jstests/core/fts5.js
+++ b/jstests/core/fts5.js
@@ -12,7 +12,7 @@ t.drop();
 t.save({_id: 1, x: [{a: "az"}, {a: "b"}, {a: "x"}], y: ["c", "d", "m"], z: 1});
 t.save({_id: 2, x: [{a: "c"}, {a: "d"}, {a: "y"}], y: ["az", "b", "n"], z: 2});
 
-t.ensureIndex({y: "text", z: 1}, {weights: {"x.a": 10}});
+t.createIndex({y: "text", z: 1}, {weights: {"x.a": 10}});
 
 assert.eq([1, 2], queryIDS(t, "az"), "A1");
 assert.eq([2, 1], queryIDS(t, "d"), "A2");
diff --git a/jstests/core/fts6.js b/jstests/core/fts6.js
index 7216fc728e9..ab757b81d59 100644
--- a/jstests/core/fts6.js
+++ b/jstests/core/fts6.js
@@ -7,8 +7,8 @@
 var t = db.jstests_fts6;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: "text"});
+t.createIndex({a: 1});
+t.createIndex({b: "text"});
 
 t.save({_id: 1, a: 0});
 t.save({_id: 2, a: 0, b: "foo"});
diff --git a/jstests/core/fts_blog.js b/jstests/core/fts_blog.js
index cdaba7860fc..2b0fe26e095 100644
--- a/jstests/core/fts_blog.js
+++ b/jstests/core/fts_blog.js
@@ -10,7 +10,7 @@ t.save({_id: 3, title: "knives are Fun", text: "this is a new blog i am writing.
 // @tags: [
 //   sbe_incompatible,
 // ]
-t.ensureIndex({"title": "text", text: "text"}, {weights: {title: 10}});
+t.createIndex({"title": "text", text: "text"}, {weights: {title: 10}});
 
 res = t.find({"$text": {"$search": "blog"}}, {score: {"$meta": "textScore"}}).sort({
     score: {"$meta": "textScore"}
diff --git a/jstests/core/fts_blogwild.js b/jstests/core/fts_blogwild.js
index 207fea471c1..881c486edad 100644
--- a/jstests/core/fts_blogwild.js
+++ b/jstests/core/fts_blogwild.js
@@ -18,7 +18,7 @@ t.save({
 
 // default weight is 1
 // specify weights if you want a field to be more meaningull
-t.ensureIndex({dummy: "text"}, {weights: "$**"});
+t.createIndex({dummy: "text"}, {weights: "$**"});
 
 res = t.find({"$text": {"$search": "blog"}});
 assert.eq(3, res.length(), "A1");
@@ -29,7 +29,7 @@ assert.eq(3, res.length(), "B1");
 // mixing
 t.dropIndex("dummy_text");
 assert.eq(1, t.getIndexKeys().length, "C1");
-t.ensureIndex({dummy: "text"}, {weights: {"$**": 1, title: 2}});
+t.createIndex({dummy: "text"}, {weights: {"$**": 1, title: 2}});
 
 res = t.find({"$text": {"$search": "write"}}, {score: {"$meta": "textScore"}}).sort({
     score: {"$meta": "textScore"}
diff --git a/jstests/core/fts_casesensitive.js b/jstests/core/fts_casesensitive.js
index 191631a6ac0..b4a730a46b5 100644
--- a/jstests/core/fts_casesensitive.js
+++ b/jstests/core/fts_casesensitive.js
@@ -9,7 +9,7 @@ var coll = db.fts_casesensitive;
 coll.drop();
 
 assert.commandWorked(coll.insert({_id: 0, a: "The Quick Brown Fox Jumps Over The Lazy Dog"}));
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 
 assert.throws(function() {
     queryIDS(coll, "hello", null, {$caseSensitive: "invalid"});
diff --git a/jstests/core/fts_diacritic_and_caseinsensitive.js b/jstests/core/fts_diacritic_and_caseinsensitive.js
index 107ff447ec9..1b8a2d0d1e0 100644
--- a/jstests/core/fts_diacritic_and_caseinsensitive.js
+++ b/jstests/core/fts_diacritic_and_caseinsensitive.js
@@ -14,7 +14,7 @@ coll.drop();
 assert.commandWorked(coll.insert(
     {_id: 0, a: "O próximo Vôo à Noite sobre o Atlântico, Põe Freqüentemente o único Médico."}));
 
-assert.commandWorked(coll.ensureIndex({a: "text"}, {default_language: "portuguese"}));
+assert.commandWorked(coll.createIndex({a: "text"}, {default_language: "portuguese"}));
 
 assert.eq([0], queryIDS(coll, "proximo voo a", null));
 assert.eq([0], queryIDS(coll, "átlántico", null));
diff --git a/jstests/core/fts_diacritic_and_casesensitive.js b/jstests/core/fts_diacritic_and_casesensitive.js
index 0f0e63feca4..124ec9c092d 100644
--- a/jstests/core/fts_diacritic_and_casesensitive.js
+++ b/jstests/core/fts_diacritic_and_casesensitive.js
@@ -15,7 +15,7 @@ coll.drop();
 assert.commandWorked(coll.insert(
     {_id: 0, a: "O próximo Vôo à Noite sobre o Atlântico, Põe Freqüentemente o único Médico."}));
 
-assert.commandWorked(coll.ensureIndex({a: "text"}, {default_language: "portuguese"}));
+assert.commandWorked(coll.createIndex({a: "text"}, {default_language: "portuguese"}));
 
 assert.eq([0],
           queryIDS(coll, "próximo vôo à", null, {$diacriticSensitive: true, $caseSensitive: true}));
diff --git a/jstests/core/fts_diacriticsensitive.js b/jstests/core/fts_diacriticsensitive.js
index 4440e587ed7..2396860e0db 100644
--- a/jstests/core/fts_diacriticsensitive.js
+++ b/jstests/core/fts_diacriticsensitive.js
@@ -14,7 +14,7 @@ coll.drop();
 assert.commandWorked(coll.insert(
     {_id: 0, a: "O próximo vôo à noite sobre o Atlântico, põe freqüentemente o único médico."}));
 
-assert.commandWorked(coll.ensureIndex({a: "text"}, {default_language: "portuguese"}));
+assert.commandWorked(coll.createIndex({a: "text"}, {default_language: "portuguese"}));
 
 assert.throws(function() {
     queryIDS(coll, "hello", null, {$diacriticSensitive: "invalid"});
diff --git a/jstests/core/fts_explain.js b/jstests/core/fts_explain.js
index 1f1f0a0e55b..9b87cedcc51 100644
--- a/jstests/core/fts_explain.js
+++ b/jstests/core/fts_explain.js
@@ -14,7 +14,7 @@ const coll = db.fts_explain;
 let res;
 
 coll.drop();
-res = coll.ensureIndex({content: "text"}, {default_language: "none"});
+res = coll.createIndex({content: "text"}, {default_language: "none"});
 assert.commandWorked(res);
 
 res = coll.insert({content: "some data"});
diff --git a/jstests/core/fts_index.js b/jstests/core/fts_index.js
index a41ea5a8dab..3080534c434 100644
--- a/jstests/core/fts_index.js
+++ b/jstests/core/fts_index.js
@@ -27,7 +27,7 @@ coll.getDB().createCollection(coll.getName());
 //
 
 // Spec passes text-specific index validation.
-assert.commandWorked(coll.ensureIndex({a: "text"}, {name: indexName, default_language: "spanish"}));
+assert.commandWorked(coll.createIndex({a: "text"}, {name: indexName, default_language: "spanish"}));
 assert.eq(1,
           coll.getIndexes()
               .filter(function(z) {
@@ -38,7 +38,7 @@ coll.dropIndexes();
 
 // Spec fails text-specific index validation ("spanglish" unrecognized).
 assert.commandFailed(
-    coll.ensureIndex({a: "text"}, {name: indexName, default_language: "spanglish"}));
+    coll.createIndex({a: "text"}, {name: indexName, default_language: "spanglish"}));
 assert.eq(0,
           coll.getIndexes()
               .filter(function(z) {
@@ -48,7 +48,7 @@ assert.eq(0,
 coll.dropIndexes();
 
 // Spec passes general index validation.
-assert.commandWorked(coll.ensureIndex({"$**": "text"}, {name: indexName}));
+assert.commandWorked(coll.createIndex({"$**": "text"}, {name: indexName}));
 assert.eq(1,
           coll.getIndexes()
               .filter(function(z) {
@@ -58,7 +58,7 @@ assert.eq(1,
 coll.dropIndexes();
 
 // Spec fails general index validation ("a.$**" invalid field name for key).
-assert.commandFailed(coll.ensureIndex({"a.$**": "text"}, {name: indexName}));
+assert.commandFailed(coll.createIndex({"a.$**": "text"}, {name: indexName}));
 assert.eq(0,
           coll.getIndexes()
               .filter(function(z) {
@@ -68,7 +68,7 @@ assert.eq(0,
 coll.dropIndexes();
 
 // SERVER-19519 Spec fails if '_fts' is specified on a non-text index.
-assert.commandFailed(coll.ensureIndex({_fts: 1}, {name: indexName}));
+assert.commandFailed(coll.createIndex({_fts: 1}, {name: indexName}));
 assert.eq(0,
           coll.getIndexes()
               .filter(function(z) {
@@ -76,7 +76,7 @@ assert.eq(0,
               })
               .length);
 coll.dropIndexes();
-assert.commandFailed(coll.ensureIndex({_fts: "text"}, {name: indexName}));
+assert.commandFailed(coll.createIndex({_fts: "text"}, {name: indexName}));
 assert.eq(0,
           coll.getIndexes()
               .filter(function(z) {
@@ -92,22 +92,22 @@ coll.dropIndexes();
 // Can create a text index on a collection where no documents have invalid language_override.
 coll.insert({a: ""});
 coll.insert({a: "", language: "spanish"});
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 coll.drop();
 
 // Can't create a text index on a collection containing document with an invalid language_override.
 coll.insert({a: "", language: "spanglish"});
-assert.commandFailed(coll.ensureIndex({a: "text"}));
+assert.commandFailed(coll.createIndex({a: "text"}));
 coll.drop();
 
 // Can insert documents with valid language_override into text-indexed collection.
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 coll.insert({a: ""});
 assert.commandWorked(coll.insert({a: "", language: "spanish"}));
 coll.drop();
 
 // Can't insert documents with invalid language_override into text-indexed collection.
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 assert.writeError(coll.insert({a: "", language: "spanglish"}));
 coll.drop();
 
@@ -115,69 +115,69 @@ coll.drop();
 // 3. Collections may have at most one text index.
 //
 
-// ensureIndex() becomes a no-op on an equivalent index spec.
+// createIndex() becomes a no-op on an equivalent index spec.
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
 assert.eq(1, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}, {background: true}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}, {background: true}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandFailedWithCode(coll.ensureIndex({a: 1, b: 1, c: "text"}),
+assert.commandFailedWithCode(coll.createIndex({a: 1, b: 1, c: "text"}),
                              ErrorCodes.CannotCreateIndex);
 assert.commandFailedWithCode(
-    coll.ensureIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}, {weights: {b: 1}}),
+    coll.createIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}, {weights: {b: 1}}),
     ErrorCodes.IndexOptionsConflict);
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}, {default_language: "english"}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}, {default_language: "english"}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}, {textIndexVersion: 2}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}, {textIndexVersion: 2}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}, {language_override: "language"}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}, {language_override: "language"}));
 assert.eq(2, coll.getIndexes().length);
 coll.drop();
 
 // Two index specs are also considered equivalent if they differ only in 'textIndexVersion', and
-// ensureIndex() becomes a no-op on repeated requests that only differ in this way.
+// createIndex() becomes a no-op on repeated requests that only differ in this way.
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
 assert.eq(1, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 1}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 1}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 2}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 2}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 3}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 3}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 assert.eq(2, coll.getIndexes().length);
 coll.drop();
 
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
 assert.eq(1, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 3}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 3}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 2}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 2}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 1}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 1}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 assert.eq(2, coll.getIndexes().length);
 coll.drop();
 
-// ensureIndex() fails if a second text index would be built.
+// createIndex() fails if a second text index would be built.
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
 assert.eq(1, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text", c: 1}));
-assert.eq(2, coll.getIndexes().length);
-assert.commandFailed(coll.ensureIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}, {weights: {d: 1}}));
-assert.commandFailed(coll.ensureIndex({a: 1, b: "text", c: 1}, {default_language: "none"}));
-assert.commandFailed(coll.ensureIndex({a: 1, b: "text", c: 1}, {language_override: "idioma"}));
-assert.commandFailed(coll.ensureIndex({a: 1, b: "text", c: 1}, {weights: {d: 1}}));
-assert.commandFailed(coll.ensureIndex({a: 1, b: "text", d: 1}));
-assert.commandFailed(coll.ensureIndex({a: 1, d: "text", c: 1}));
-assert.commandFailed(coll.ensureIndex({b: "text"}));
-assert.commandFailed(coll.ensureIndex({b: "text", c: 1}));
-assert.commandFailed(coll.ensureIndex({a: 1, b: "text"}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text", c: 1}));
+assert.eq(2, coll.getIndexes().length);
+assert.commandFailed(coll.createIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}, {weights: {d: 1}}));
+assert.commandFailed(coll.createIndex({a: 1, b: "text", c: 1}, {default_language: "none"}));
+assert.commandFailed(coll.createIndex({a: 1, b: "text", c: 1}, {language_override: "idioma"}));
+assert.commandFailed(coll.createIndex({a: 1, b: "text", c: 1}, {weights: {d: 1}}));
+assert.commandFailed(coll.createIndex({a: 1, b: "text", d: 1}));
+assert.commandFailed(coll.createIndex({a: 1, d: "text", c: 1}));
+assert.commandFailed(coll.createIndex({b: "text"}));
+assert.commandFailed(coll.createIndex({b: "text", c: 1}));
+assert.commandFailed(coll.createIndex({a: 1, b: "text"}));
 
 coll.dropIndexes();
 
@@ -185,7 +185,7 @@ coll.dropIndexes();
 // 4. Text indexes properly handle large keys.
 //
 
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 
 var longstring = "";
 var longstring2 = "";
@@ -201,7 +201,7 @@ coll.dropIndexes();
 //
 // 5. Bad weights test cases.
 //
-assert.commandFailed(coll.ensureIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}, {weights: {}}));
-assert.commandFailed(coll.ensureIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}));
+assert.commandFailed(coll.createIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}, {weights: {}}));
+assert.commandFailed(coll.createIndex({a: 1, _fts: "text", _ftsx: 1, c: 1}));
 
 coll.drop();
diff --git a/jstests/core/fts_index2.js b/jstests/core/fts_index2.js
index 1c8454002a7..3ae6e45214e 100644
--- a/jstests/core/fts_index2.js
+++ b/jstests/core/fts_index2.js
@@ -14,7 +14,7 @@ coll1.drop();
 coll2.drop();
 
 assert.commandWorked(coll1.insert({a: {b: "some content"}}));
-assert.commandWorked(coll1.ensureIndex({"$**": "text"}));
+assert.commandWorked(coll1.createIndex({"$**": "text"}));
 assert.eq(1, coll1.count({$text: {$search: "content"}}));
 
 // Rename within same database.
diff --git a/jstests/core/fts_index3.js b/jstests/core/fts_index3.js
index 02bd9559591..0f57c7a9d80 100644
--- a/jstests/core/fts_index3.js
+++ b/jstests/core/fts_index3.js
@@ -12,7 +12,7 @@ var coll = db.fts_index3;
 // 1) Create a text index on a single field, insert a document, update the value of the field, and
 // verify that $text with the new value returns the document.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 assert.commandWorked(coll.insert({a: "hello"}));
 assert.eq(1, coll.find({$text: {$search: "hello"}}).itcount());
 assert.commandWorked(coll.update({}, {$set: {a: "world"}}));
@@ -21,7 +21,7 @@ assert.eq(1, coll.find({$text: {$search: "world"}}).itcount());
 
 // 2) Same as #1, but with a wildcard text index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"$**": "text"}));
+assert.commandWorked(coll.createIndex({"$**": "text"}));
 assert.commandWorked(coll.insert({a: "hello"}));
 assert.eq(1, coll.find({$text: {$search: "hello"}}).itcount());
 assert.commandWorked(coll.update({}, {$set: {a: "world"}}));
@@ -31,7 +31,7 @@ assert.eq(1, coll.find({$text: {$search: "world"}}).itcount());
 // 3) Create a compound text index with an index prefix, insert a document, update the value of the
 // index prefix field, and verify that $text with the new value returns the document.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1, b: "text"}));
+assert.commandWorked(coll.createIndex({a: 1, b: "text"}));
 assert.commandWorked(coll.insert({a: 1, b: "hello"}));
 assert.eq(1, coll.find({a: 1, $text: {$search: "hello"}}).itcount());
 assert.commandWorked(coll.update({}, {$set: {a: 2}}));
@@ -40,7 +40,7 @@ assert.eq(1, coll.find({a: 2, $text: {$search: "hello"}}).itcount());
 
 // 4) Same as #3, but with a wildcard text index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1, "$**": "text"}));
+assert.commandWorked(coll.createIndex({a: 1, "$**": "text"}));
 assert.commandWorked(coll.insert({a: 1, b: "hello"}));
 assert.eq(1, coll.find({a: 1, $text: {$search: "hello"}}).itcount());
 assert.commandWorked(coll.update({}, {$set: {a: 2}}));
@@ -50,7 +50,7 @@ assert.eq(1, coll.find({a: 2, $text: {$search: "hello"}}).itcount());
 // 5) Create a compound text index with an index suffix, insert a document, update the value of the
 // index suffix field, and verify that $text with the new value returns the document.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: "text", b: 1}));
+assert.commandWorked(coll.createIndex({a: "text", b: 1}));
 assert.commandWorked(coll.insert({a: "hello", b: 1}));
 assert.eq(1, coll.find({b: 1, $text: {$search: "hello"}}).itcount());
 assert.commandWorked(coll.update({}, {$set: {b: 2}}));
@@ -59,7 +59,7 @@ assert.eq(1, coll.find({b: 2, $text: {$search: "hello"}}).itcount());
 
 // 6) Same as #5, but with a wildcard text index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"$**": "text", b: 1}));
+assert.commandWorked(coll.createIndex({"$**": "text", b: 1}));
 assert.commandWorked(coll.insert({a: "hello", b: 1}));
 assert.eq(1, coll.find({b: 1, $text: {$search: "hello"}}).itcount());
 assert.commandWorked(coll.update({}, {$set: {b: 2}}));
@@ -69,7 +69,7 @@ assert.eq(1, coll.find({b: 2, $text: {$search: "hello"}}).itcount());
 // 7) Create a text index on a single field, insert a document, update the language of the document
 // (so as to change the stemming), and verify that $text with the new language returns the document.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: "text"}));
+assert.commandWorked(coll.createIndex({a: "text"}));
 assert.commandWorked(coll.insert({a: "testing", language: "es"}));
 assert.eq(1, coll.find({$text: {$search: "testing", $language: "es"}}).itcount());
 assert.eq(0, coll.find({$text: {$search: "testing", $language: "en"}}).itcount());
@@ -79,7 +79,7 @@ assert.eq(1, coll.find({$text: {$search: "testing", $language: "en"}}).itcount()
 
 // 8) Same as #7, but with a wildcard text index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"$**": "text"}));
+assert.commandWorked(coll.createIndex({"$**": "text"}));
 assert.commandWorked(coll.insert({a: "testing", language: "es"}));
 assert.eq(1, coll.find({$text: {$search: "testing", $language: "es"}}).itcount());
 assert.eq(0, coll.find({$text: {$search: "testing", $language: "en"}}).itcount());
@@ -91,7 +91,7 @@ assert.eq(1, coll.find({$text: {$search: "testing", $language: "en"}}).itcount()
 // subdocument (so as to change the stemming), and verify that $text with the new language returns
 // the document.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"a.b": "text"}));
+assert.commandWorked(coll.createIndex({"a.b": "text"}));
 assert.commandWorked(coll.insert({a: {b: "testing", language: "es"}}));
 assert.eq(1, coll.find({$text: {$search: "testing", $language: "es"}}).itcount());
 assert.eq(0, coll.find({$text: {$search: "testing", $language: "en"}}).itcount());
@@ -101,7 +101,7 @@ assert.eq(1, coll.find({$text: {$search: "testing", $language: "en"}}).itcount()
 
 // 10) Same as #9, but with a wildcard text index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"$**": "text"}));
+assert.commandWorked(coll.createIndex({"$**": "text"}));
 assert.commandWorked(coll.insert({a: {b: "testing", language: "es"}}));
 assert.eq(1, coll.find({$text: {$search: "testing", $language: "es"}}).itcount());
 assert.eq(0, coll.find({$text: {$search: "testing", $language: "en"}}).itcount());
@@ -113,7 +113,7 @@ assert.eq(1, coll.find({$text: {$search: "testing", $language: "en"}}).itcount()
 // update the language of the document (so as to change the stemming), and verify that $text with
 // the new language returns the document.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: "text"}, {language_override: "idioma"}));
+assert.commandWorked(coll.createIndex({a: "text"}, {language_override: "idioma"}));
 assert.commandWorked(coll.insert({a: "testing", idioma: "es"}));
 assert.eq(1, coll.find({$text: {$search: "testing", $language: "es"}}).itcount());
 assert.eq(0, coll.find({$text: {$search: "testing", $language: "en"}}).itcount());
@@ -123,7 +123,7 @@ assert.eq(1, coll.find({$text: {$search: "testing", $language: "en"}}).itcount()
 
 // 12) Same as #11, but with a wildcard text index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"$**": "text"}, {language_override: "idioma"}));
+assert.commandWorked(coll.createIndex({"$**": "text"}, {language_override: "idioma"}));
 assert.commandWorked(coll.insert({a: "testing", idioma: "es"}));
 assert.eq(1, coll.find({$text: {$search: "testing", $language: "es"}}).itcount());
 assert.eq(0, coll.find({$text: {$search: "testing", $language: "en"}}).itcount());
diff --git a/jstests/core/fts_index_version1.js b/jstests/core/fts_index_version1.js
index 8ae979c7dbe..57b7c7710b6 100644
--- a/jstests/core/fts_index_version1.js
+++ b/jstests/core/fts_index_version1.js
@@ -3,19 +3,19 @@ var coll = db.fts_index_version1;
 
 // Test basic English search.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: "text"}, {textIndexVersion: 1}));
+assert.commandWorked(coll.createIndex({a: "text"}, {textIndexVersion: 1}));
 assert.commandWorked(coll.insert({a: "running"}));
 assert.eq(1, coll.count({$text: {$search: "run"}}));
 
 // Test search with a "language alias" only recognized in textIndexVersion:1 (note that the stopword
 // machinery doesn't recognize these aliases).
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: "text"}, {default_language: "eng", textIndexVersion: 1}));
+assert.commandWorked(coll.createIndex({a: "text"}, {default_language: "eng", textIndexVersion: 1}));
 assert.commandWorked(coll.insert({a: "running"}));
 assert.eq(1, coll.count({$text: {$search: "run"}}));
 
 // Test that textIndexVersion:1 indexes ignore subdocument language annotations.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({"a.b": "text"}, {textIndexVersion: 1}));
+assert.commandWorked(coll.createIndex({"a.b": "text"}, {textIndexVersion: 1}));
 assert.commandWorked(coll.insert({language: "none", a: {language: "english", b: "the"}}));
 assert.eq(1, coll.count({$text: {$search: "the", $language: "none"}}));
diff --git a/jstests/core/fts_index_version2.js b/jstests/core/fts_index_version2.js
index 10f803f30c6..1e579ba12cb 100644
--- a/jstests/core/fts_index_version2.js
+++ b/jstests/core/fts_index_version2.js
@@ -15,7 +15,7 @@ assert.commandWorked(coll.insert(
     {_id: 0, a: "O próximo Vôo à Noite sobre o Atlântico, Põe Freqüentemente o único Médico."}));
 
 assert.commandWorked(
-    coll.ensureIndex({a: "text"}, {default_language: "portuguese", textIndexVersion: 2}));
+    coll.createIndex({a: "text"}, {default_language: "portuguese", textIndexVersion: 2}));
 
 assert.eq([0], queryIDS(coll, "próximo vôo à", null));
 assert.eq([0], queryIDS(coll, "atlântico", null));
diff --git a/jstests/core/fts_mix.js b/jstests/core/fts_mix.js
index abfdcc6aefd..cdaaf1d17ff 100644
--- a/jstests/core/fts_mix.js
+++ b/jstests/core/fts_mix.js
@@ -77,7 +77,7 @@ tc.save({
 // -------------------------------------------- INDEXING & WEIGHTING -------------------------------
 
 // start with basic index, one item with default weight
-tc.ensureIndex({"title": "text"});
+tc.createIndex({"title": "text"});
 
 // test the single result case..
 res = tc.find({"$text": {"$search": "Victoria"}});
@@ -87,19 +87,19 @@ assert.eq(10, res[0]._id);
 tc.dropIndexes();
 
 // now let's see about multiple fields, with specific weighting
-tc.ensureIndex({"title": "text", "text": "text"}, {weights: {"title": 10}});
+tc.createIndex({"title": "text", "text": "text"}, {weights: {"title": 10}});
 assert(resultsEq([9, 7, 8], queryIDS(tc, "members physics")));
 
 tc.dropIndexes();
 
 // test all-1 weighting with "$**"
-tc.ensureIndex({"$**": "text"});
+tc.createIndex({"$**": "text"});
 assert(resultsEq([2, 8, 7], queryIDS(tc, "family tea estate")));
 
 tc.dropIndexes();
 
 // non-1 weight on "$**" + other weight specified for some field
-tc.ensureIndex({"$**": "text"}, {weights: {"$**": 10, "text": 2}});
+tc.createIndex({"$**": "text"}, {weights: {"$**": 10, "text": 2}});
 assert(resultsEq([7, 5], queryIDS(tc, "Olympic Games gold medal")));
 
 tc.dropIndexes();
@@ -108,7 +108,7 @@ tc.dropIndexes();
 // ------------------------------------------
 
 // go back to "$**": 1, "title": 10.. and test more specific "search" functionality!
-tc.ensureIndex({"$**": "text"}, {weights: {"title": 10}});
+tc.createIndex({"$**": "text"}, {weights: {"title": 10}});
 
 // -------------------------------------------- STEMMING -------------------------------------------
 
diff --git a/jstests/core/fts_partition1.js b/jstests/core/fts_partition1.js
index 055f574baf1..efc148da675 100644
--- a/jstests/core/fts_partition1.js
+++ b/jstests/core/fts_partition1.js
@@ -13,7 +13,7 @@ t.insert({_id: 2, x: 1, y: "bar"});
 t.insert({_id: 3, x: 2, y: "foo"});
 t.insert({_id: 4, x: 2, y: "bar"});
 
-t.ensureIndex({x: 1, y: "text"});
+t.createIndex({x: 1, y: "text"});
 
 assert.throws(function() {
     const cursor = t.find({"$text": {"$search": "foo"}});
diff --git a/jstests/core/fts_partition_no_multikey.js b/jstests/core/fts_partition_no_multikey.js
index af28380a804..b819c3abfbd 100644
--- a/jstests/core/fts_partition_no_multikey.js
+++ b/jstests/core/fts_partition_no_multikey.js
@@ -1,7 +1,7 @@
 t = db.fts_partition_no_multikey;
 t.drop();
 
-t.ensureIndex({x: 1, y: "text"});
+t.createIndex({x: 1, y: "text"});
 
 assert.commandWorked(t.insert({x: 5, y: "this is fun"}));
 
diff --git a/jstests/core/fts_phrase.js b/jstests/core/fts_phrase.js
index eae0a1c268d..dfe9d3692af 100644
--- a/jstests/core/fts_phrase.js
+++ b/jstests/core/fts_phrase.js
@@ -11,7 +11,7 @@ t.save({_id: 1, title: "my blog post", text: "i am writing a blog. yay"});
 t.save({_id: 2, title: "my 2nd post", text: "this is a new blog i am typing. yay"});
 t.save({_id: 3, title: "knives are Fun", text: "this is a new blog i am writing. yay"});
 
-t.ensureIndex({"title": "text", text: "text"}, {weights: {title: 10}});
+t.createIndex({"title": "text", text: "text"}, {weights: {title: 10}});
 
 res = t.find({"$text": {"$search": "blog write"}}, {score: {"$meta": "textScore"}}).sort({
     score: {"$meta": "textScore"}
diff --git a/jstests/core/geo1.js b/jstests/core/geo1.js
index 7917799377e..8a80f59d692 100644
--- a/jstests/core/geo1.js
+++ b/jstests/core/geo1.js
@@ -19,10 +19,10 @@ assert.commandWorked(t.insert({zip: "94061", loc: [37.463911, 122.23396]}));
 
 // test "2d" has to be first
 assert.eq(1, t.getIndexKeys().length, "S1");
-t.ensureIndex({zip: 1, loc: "2d"});
+t.createIndex({zip: 1, loc: "2d"});
 assert.eq(1, t.getIndexKeys().length, "S2");
 
-t.ensureIndex(idx);
+t.createIndex(idx);
 assert.eq(2, t.getIndexKeys().length, "S3");
 
 assert.eq(3, t.count(), "B1");
@@ -42,5 +42,5 @@ assert.eq("06525", t.find({loc: wb.loc})[0].zip, "C3");
 
 t.drop();
 
-t.ensureIndex({loc: "2d"}, {min: -500, max: 500, bits: 4});
+t.createIndex({loc: "2d"}, {min: -500, max: 500, bits: 4});
 assert.commandWorked(t.insert({loc: [200, 200]}));
diff --git a/jstests/core/geo10.js b/jstests/core/geo10.js
index c33f90cdfbd..b330ce52911 100644
--- a/jstests/core/geo10.js
+++ b/jstests/core/geo10.js
@@ -10,7 +10,7 @@
 coll = db.geo10;
 coll.drop();
 
-assert.commandWorked(db.geo10.ensureIndex({c: '2d', t: 1}, {min: 0, max: Math.pow(2, 40)}));
+assert.commandWorked(db.geo10.createIndex({c: '2d', t: 1}, {min: 0, max: Math.pow(2, 40)}));
 assert.eq(2, db.geo10.getIndexes().length, "A3");
 
 assert.commandWorked(db.geo10.insert({c: [1, 1], t: 1}));
diff --git a/jstests/core/geo2.js b/jstests/core/geo2.js
index 01a4c467339..b0552e2f773 100644
--- a/jstests/core/geo2.js
+++ b/jstests/core/geo2.js
@@ -18,7 +18,7 @@ t.insert(arr);
 assert.eq(t.count(), 100 * 100);
 assert.eq(t.count(), n - 1);
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 function a(cur) {
     var total = 0;
diff --git a/jstests/core/geo3.js b/jstests/core/geo3.js
index e75c9b14245..40a3d9a5e75 100644
--- a/jstests/core/geo3.js
+++ b/jstests/core/geo3.js
@@ -19,7 +19,7 @@ t.insert(arr);
 assert.eq(t.count(), 100 * 100);
 assert.eq(t.count(), n - 1);
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 // Test the "query" parameter in $geoNear.
 
@@ -52,7 +52,7 @@ function testFiltering(msg) {
 testFiltering("just loc");
 
 assert.commandWorked(t.dropIndex({loc: "2d"}));
-assert.commandWorked(t.ensureIndex({loc: "2d", a: 1}));
+assert.commandWorked(t.createIndex({loc: "2d", a: 1}));
 
 res = t.aggregate([
            {$geoNear: {near: [50, 50], distanceField: "dist", query: {a: 2}}},
@@ -64,7 +64,7 @@ res.forEach(doc => assert.eq(2, doc.a, tojson(doc)));
 testFiltering("loc and a");
 
 assert.commandWorked(t.dropIndex({loc: "2d", a: 1}));
-assert.commandWorked(t.ensureIndex({loc: "2d", b: 1}));
+assert.commandWorked(t.createIndex({loc: "2d", b: 1}));
 
 testFiltering("loc and b");
 
diff --git a/jstests/core/geo6.js b/jstests/core/geo6.js
index d6b43771b2c..0ee06508ea2 100644
--- a/jstests/core/geo6.js
+++ b/jstests/core/geo6.js
@@ -6,7 +6,7 @@
 t = db.geo6;
 t.drop();
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 assert.eq(0, t.find().itcount(), "pre0");
 assert.eq(0, t.find({loc: {$near: [50, 50]}}).itcount(), "pre1");
diff --git a/jstests/core/geo7.js b/jstests/core/geo7.js
index 4316c8d6c03..9d1b7f574ca 100644
--- a/jstests/core/geo7.js
+++ b/jstests/core/geo7.js
@@ -6,13 +6,13 @@ t.insert({_id: 2, y: [1, 1], z: 3});
 t.insert({_id: 3, y: [1, 1], z: 4});
 t.insert({_id: 4, y: [1, 1], z: 5});
 
-t.ensureIndex({y: "2d", z: 1});
+t.createIndex({y: "2d", z: 1});
 
 assert.eq(1, t.find({y: [1, 1], z: 3}).itcount(), "A1");
 
 t.dropIndex({y: "2d", z: 1});
 
-t.ensureIndex({y: "2d"});
+t.createIndex({y: "2d"});
 assert.eq(1, t.find({y: [1, 1], z: 3}).itcount(), "A2");
 
 t.insert({_id: 5, y: 5});
diff --git a/jstests/core/geo9.js b/jstests/core/geo9.js
index eacd30f9a6d..4204c842987 100644
--- a/jstests/core/geo9.js
+++ b/jstests/core/geo9.js
@@ -14,8 +14,8 @@ t.save({_id: 4, a: [50, 50], b: [10, 10]});
 t.save({_id: 5, a: [51, 51], b: [11, 11]});
 t.save({_id: 6, a: [52, 52], b: [12, 12]});
 
-t.ensureIndex({a: "2d"});
-t.ensureIndex({b: "2d"});
+t.createIndex({a: "2d"});
+t.createIndex({b: "2d"});
 
 function check(field) {
     var q = {};
diff --git a/jstests/core/geo_2d_explain.js b/jstests/core/geo_2d_explain.js
index 370ef47e708..109c5618795 100644
--- a/jstests/core/geo_2d_explain.js
+++ b/jstests/core/geo_2d_explain.js
@@ -13,7 +13,7 @@ var n = 1000;
 
 // insert n documents with integer _id, a can be 1-5, loc is close to [40, 40]
 t.drop();
-t.ensureIndex({loc: "2d", _id: 1});
+t.createIndex({loc: "2d", _id: 1});
 
 var x = 40;
 var y = 40;
diff --git a/jstests/core/geo_2d_with_geojson_point.js b/jstests/core/geo_2d_with_geojson_point.js
index bb35fccd9da..3930f3c2c96 100644
--- a/jstests/core/geo_2d_with_geojson_point.js
+++ b/jstests/core/geo_2d_with_geojson_point.js
@@ -4,7 +4,7 @@
 
 var t = db.geo_2d_with_geojson_point;
 t.drop();
-t.ensureIndex({loc: '2d'});
+t.createIndex({loc: '2d'});
 
 var geoJSONPoint = {type: 'Point', coordinates: [0, 0]};
 
diff --git a/jstests/core/geo_allowedcomparisons.js b/jstests/core/geo_allowedcomparisons.js
index c1ef4efcba1..01795941533 100644
--- a/jstests/core/geo_allowedcomparisons.js
+++ b/jstests/core/geo_allowedcomparisons.js
@@ -33,7 +33,7 @@ oldPolygon = [[-5, -5], [-5, 5], [5, 5], [5, -5], [-5, -5]];
 oldCenter = [[0, 0], 1];
 
 t.drop();
-t.ensureIndex({geo: "2d"});
+t.createIndex({geo: "2d"});
 // 2d doesn't know what to do w/this
 assert.writeError(t.insert({geo: geojsonPoint}));
 // Old points are OK.
@@ -102,7 +102,7 @@ t.dropIndex({geo: "2d"});
 runTests();
 
 // 2dsphere index now.
-assert.commandWorked(t.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(t.createIndex({geo: "2dsphere"}));
 // 2dsphere does not support arrays of points.
 assert.writeError(t.insert({geo: [geojsonPoint2, geojsonPoint]}));
 runTests();
diff --git a/jstests/core/geo_array0.js b/jstests/core/geo_array0.js
index 0f27de02e49..8a4e81283f8 100644
--- a/jstests/core/geo_array0.js
+++ b/jstests/core/geo_array0.js
@@ -16,7 +16,7 @@ function test(index) {
     assert.commandWorked(res);
 
     if (index) {
-        assert.commandWorked(t.ensureIndex({loc: "2d", zip: 1}));
+        assert.commandWorked(t.createIndex({loc: "2d", zip: 1}));
         assert.eq(2, t.getIndexKeys().length);
     }
 
diff --git a/jstests/core/geo_array1.js b/jstests/core/geo_array1.js
index 08b6060f3cc..6066ed1dc6f 100644
--- a/jstests/core/geo_array1.js
+++ b/jstests/core/geo_array1.js
@@ -21,7 +21,7 @@ function test(index) {
     }
 
     if (index) {
-        t.ensureIndex({loc: "2d"});
+        t.createIndex({loc: "2d"});
     }
 
     // Pull them back
diff --git a/jstests/core/geo_array2.js b/jstests/core/geo_array2.js
index d2a197891e6..2a7a1303e0c 100644
--- a/jstests/core/geo_array2.js
+++ b/jstests/core/geo_array2.js
@@ -27,7 +27,7 @@ for (var i = -1; i < 2; i++) {
     }
 }
 
-assert.commandWorked(t.ensureIndex({loc: "2d", type: 1}));
+assert.commandWorked(t.createIndex({loc: "2d", type: 1}));
 
 print("Starting testing phase... ");
 
diff --git a/jstests/core/geo_big_polygon.js b/jstests/core/geo_big_polygon.js
index eb2a24ad719..db0d00cf6ff 100644
--- a/jstests/core/geo_big_polygon.js
+++ b/jstests/core/geo_big_polygon.js
@@ -10,7 +10,7 @@
 var coll = db.geo_big_polygon;
 coll.drop();
 
-// coll.ensureIndex({ loc : "2dsphere" });
+// coll.createIndex({ loc : "2dsphere" });
 
 var bigCRS = {type: "name", properties: {name: "urn:x-mongodb:crs:strictwinding:EPSG:4326"}};
 
@@ -56,7 +56,7 @@ assert.eq(coll.find({loc: {$geoIntersects: {$geometry: bigPoly20}}}).count(), 4)
 assert.eq(coll.find({loc: {$geoWithin: {$geometry: bigPoly20Comp}}}).count(), 1);
 assert.eq(coll.find({loc: {$geoIntersects: {$geometry: bigPoly20Comp}}}).count(), 2);
 
-assert.commandWorked(coll.ensureIndex({loc: "2dsphere"}));
+assert.commandWorked(coll.createIndex({loc: "2dsphere"}));
 
 assert.eq(coll.find({loc: {$geoWithin: {$geometry: bigPoly20}}}).count(), 3);
 assert.eq(coll.find({loc: {$geoIntersects: {$geometry: bigPoly20}}}).count(), 4);
@@ -81,11 +81,11 @@ assert.eq(coll.find({loc: {$geoWithin: {$geometry: bigPoly20Comp}}}).count(), 1)
 assert.eq(coll.find({loc: {$geoIntersects: {$geometry: bigPoly20Comp}}}).count(), 2);
 
 // 2. Building index fails due to big polygon
-assert.commandFailed(coll.ensureIndex({loc: "2dsphere"}));
+assert.commandFailed(coll.createIndex({loc: "2dsphere"}));
 
 // 3. After removing big polygon, index builds successfully
 assert.commandWorked(coll.remove({_id: "bigPoly10"}));
-assert.commandWorked(coll.ensureIndex({loc: "2dsphere"}));
+assert.commandWorked(coll.createIndex({loc: "2dsphere"}));
 
 // 4. With index, insert fails.
 assert.writeError(coll.insert({_id: "bigPoly10", loc: bigPoly10}));
diff --git a/jstests/core/geo_big_polygon2.js b/jstests/core/geo_big_polygon2.js
index 80339cb4fed..53e0631e791 100644
--- a/jstests/core/geo_big_polygon2.js
+++ b/jstests/core/geo_big_polygon2.js
@@ -560,7 +560,7 @@ const nsidedPolys = [
 ];
 
 // Populate with 2dsphere index
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}), "create 2dsphere index");
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}), "create 2dsphere index");
 
 // Insert objects into collection
 objects.forEach(function(o) {
@@ -573,10 +573,10 @@ objects.forEach(function(o) {
 });
 
 // Try creating other index types
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere", a: 1}), "compound index, geo");
+assert.commandWorked(coll.createIndex({geo: "2dsphere", a: 1}), "compound index, geo");
 // These other index types will fail because of the GeoJSON documents
-assert.commandFailed(coll.ensureIndex({geo: "2dsphere", a: "text"}), "compound index, geo & text");
-assert.commandFailed(coll.ensureIndex({geo: "2d"}), "2d index");
+assert.commandFailed(coll.createIndex({geo: "2dsphere", a: "text"}), "compound index, geo & text");
+assert.commandFailed(coll.createIndex({geo: "2d"}), "2d index");
 
 totalObjects = coll.count();
 
@@ -589,7 +589,7 @@ indexes.forEach(function(index) {
 
     if (index != "none") {
         // Create index
-        assert.commandWorked(coll.ensureIndex({geo: index}), "create " + index + " index");
+        assert.commandWorked(coll.createIndex({geo: index}), "create " + index + " index");
     }
 
     // These polygons should not be queryable
diff --git a/jstests/core/geo_big_polygon3.js b/jstests/core/geo_big_polygon3.js
index a55ce87c3d6..cd4591dd66a 100644
--- a/jstests/core/geo_big_polygon3.js
+++ b/jstests/core/geo_big_polygon3.js
@@ -63,7 +63,7 @@ var bigPoly = {
 };
 
 // 2dsphere index required
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}), "2dsphere index");
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}), "2dsphere index");
 
 // $nearSphere on big polygon should fail
 assert.throws(function() {
@@ -222,7 +222,7 @@ assert.eq(totalDocs,
           "crs84CRS or epsg4326CRS intersects");
 
 // Add index and look again for stored point & spherical CRS documents
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}), "2dsphere index");
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}), "2dsphere index");
 
 assert.eq(totalDocs,
           coll.count({geo: {$geoWithin: {$geometry: poly}}}),
diff --git a/jstests/core/geo_borders.js b/jstests/core/geo_borders.js
index 8eac710db0f..01989a445bc 100644
--- a/jstests/core/geo_borders.js
+++ b/jstests/core/geo_borders.js
@@ -24,11 +24,11 @@ overallMax = 1;
 
 // Create a point index slightly smaller than the points we have
 var res =
-    t.ensureIndex({loc: "2d"}, {max: overallMax - epsilon / 2, min: overallMin + epsilon / 2});
+    t.createIndex({loc: "2d"}, {max: overallMax - epsilon / 2, min: overallMin + epsilon / 2});
 assert.commandFailed(res);
 
 // Create a point index only slightly bigger than the points we have
-res = t.ensureIndex({loc: "2d"}, {max: overallMax + epsilon, min: overallMin - epsilon});
+res = t.createIndex({loc: "2d"}, {max: overallMax + epsilon, min: overallMin - epsilon});
 assert.commandWorked(res);
 
 // ************
diff --git a/jstests/core/geo_box1.js b/jstests/core/geo_box1.js
index 300e65c2dc6..28fe85c83cf 100644
--- a/jstests/core/geo_box1.js
+++ b/jstests/core/geo_box1.js
@@ -14,7 +14,7 @@ for (x = 0; x <= 20; x++) {
     }
 }
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 searches = [
     [[1, 2], [4, 5]],
diff --git a/jstests/core/geo_box2.js b/jstests/core/geo_box2.js
index f0f99b15ea0..e4e51ec9e10 100644
--- a/jstests/core/geo_box2.js
+++ b/jstests/core/geo_box2.js
@@ -14,10 +14,10 @@ for (i = 1; i < 10; i++) {
     }
 }
 
-t.ensureIndex({"loc": "2d"});
+t.createIndex({"loc": "2d"});
 assert.eq(9, t.find({loc: {$within: {$box: [[4, 4], [6, 6]]}}}).itcount(), "A1");
 
 t.dropIndex({"loc": "2d"});
 
-t.ensureIndex({"loc": "2d"}, {"min": 0, "max": 10});
+t.createIndex({"loc": "2d"}, {"min": 0, "max": 10});
 assert.eq(9, t.find({loc: {$within: {$box: [[4, 4], [6, 6]]}}}).itcount(), "B1");
diff --git a/jstests/core/geo_box3.js b/jstests/core/geo_box3.js
index 7f9dd12ea60..4a91ffb0d1d 100644
--- a/jstests/core/geo_box3.js
+++ b/jstests/core/geo_box3.js
@@ -7,7 +7,7 @@
 t = db.geo_box3;
 t.drop();
 t.insert({point: {x: -15000000, y: 10000000}});
-t.ensureIndex({point: "2d"}, {min: -21000000, max: 21000000});
+t.createIndex({point: "2d"}, {min: -21000000, max: 21000000});
 var c = t.find({point: {"$within": {"$box": [[-20000000, 7000000], [0, 15000000]]}}});
 assert.eq(1, c.count(), "A1");
 
@@ -15,7 +15,7 @@ assert.eq(1, c.count(), "A1");
 t = db.geo_box3;
 t.drop();
 t.insert({point: {x: -15, y: 10}});
-t.ensureIndex({point: "2d"}, {min: -21, max: 21});
+t.createIndex({point: "2d"}, {min: -21, max: 21});
 var c = t.find({point: {"$within": {"$box": [[-20, 7], [0, 15]]}}});
 assert.eq(1, c.count(), "B1");
 
@@ -24,13 +24,13 @@ assert.eq(1, c.count(), "B1");
 t = db.geo_box3;
 t.drop();
 t.insert({point: {x: 1.0, y: 1.0}});
-t.ensureIndex({point: "2d"}, {min: -2, max: 2});
+t.createIndex({point: "2d"}, {min: -2, max: 2});
 var c = t.find({point: {"$within": {"$box": [[.1, .1], [1.99, 1.99]]}}});
 assert.eq(1, c.count(), "C1");
 
 t = db.geo_box3;
 t.drop();
 t.insert({point: {x: 3.9, y: 3.9}});
-t.ensureIndex({point: "2d"}, {min: 0, max: 4});
+t.createIndex({point: "2d"}, {min: 0, max: 4});
 var c = t.find({point: {"$within": {"$box": [[2.05, 2.05], [3.99, 3.99]]}}});
 assert.eq(1, c.count(), "D1");
diff --git a/jstests/core/geo_center_sphere1.js b/jstests/core/geo_center_sphere1.js
index df3ea9bb36c..cbef0b4302d 100644
--- a/jstests/core/geo_center_sphere1.js
+++ b/jstests/core/geo_center_sphere1.js
@@ -45,7 +45,7 @@ function test(index) {
     assert.commandWorked(bulk.execute());
 
     if (index) {
-        t.ensureIndex({loc: index});
+        t.createIndex({loc: index});
     }
 
     for (i = 0; i < searches.length; i++) {
diff --git a/jstests/core/geo_center_sphere2.js b/jstests/core/geo_center_sphere2.js
index 4a263cba259..2b5e8be5cab 100644
--- a/jstests/core/geo_center_sphere2.js
+++ b/jstests/core/geo_center_sphere2.js
@@ -50,7 +50,7 @@ for (var test = 0; test < numTests; test++) {
     do {
         t.drop();
         startPoint = randomPoint();
-        t.ensureIndex({loc: "2d"}, {bits: bits});
+        t.createIndex({loc: "2d"}, {bits: bits});
     } while (!pointIsOK(startPoint, radius));
 
     var pointsIn = 0;
diff --git a/jstests/core/geo_circle1.js b/jstests/core/geo_circle1.js
index 65d2a467eab..0df085bcb4d 100644
--- a/jstests/core/geo_circle1.js
+++ b/jstests/core/geo_circle1.js
@@ -29,7 +29,7 @@ for (x = 0; x <= 20; x++) {
     }
 }
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 for (i = 0; i < searches.length; i++) {
     // print( tojson( searches[i] ) + "\t" + correct[i].length )
diff --git a/jstests/core/geo_circle2.js b/jstests/core/geo_circle2.js
index 30a826b4f27..6be02377259 100644
--- a/jstests/core/geo_circle2.js
+++ b/jstests/core/geo_circle2.js
@@ -7,7 +7,7 @@
 t = db.geo_circle2;
 t.drop();
 
-t.ensureIndex({loc: "2d", categories: 1}, {"name": "placesIdx", "min": -100, "max": 100});
+t.createIndex({loc: "2d", categories: 1}, {"name": "placesIdx", "min": -100, "max": 100});
 
 t.insert(
     {"uid": 368900, "loc": {"x": -36, "y": -8}, "categories": ["sports", "hotel", "restaurant"]});
diff --git a/jstests/core/geo_circle2a.js b/jstests/core/geo_circle2a.js
index b084d1027ec..f647bdc82ea 100644
--- a/jstests/core/geo_circle2a.js
+++ b/jstests/core/geo_circle2a.js
@@ -6,7 +6,7 @@
 var coll = db.geo_circle2a;
 coll.drop();
 coll.insert({p: [1112, 3473], t: [{k: 'a', v: 'b'}, {k: 'c', v: 'd'}]});
-coll.ensureIndex({p: '2d', 't.k': 1}, {min: 0, max: 10000});
+coll.createIndex({p: '2d', 't.k': 1}, {min: 0, max: 10000});
 
 // Succeeds, since on direct lookup should not use the index
 assert(1 == coll.find({p: [1112, 3473], 't.k': 'a'}).count(), "A");
@@ -18,7 +18,7 @@ coll.drop();
 coll.insert({point: [1, 10], tags: [{k: 'key', v: 'value'}, {k: 'key2', v: 123}]});
 coll.insert({point: [1, 10], tags: [{k: 'key', v: 'value'}]});
 
-coll.ensureIndex({point: "2d", "tags.k": 1, "tags.v": 1});
+coll.createIndex({point: "2d", "tags.k": 1, "tags.v": 1});
 
 // Succeeds, since should now lookup multi-keys correctly
 assert(2 == coll.find({point: {$within: {$box: [[0, 0], [12, 12]]}}}).count(), "C");
@@ -31,7 +31,7 @@ coll.drop();
 coll.insert({point: [1, 10], tags: [{k: {'hello': 'world'}, v: 'value'}, {k: 'key2', v: 123}]});
 coll.insert({point: [1, 10], tags: [{k: 'key', v: 'value'}]});
 
-coll.ensureIndex({point: "2d", "tags.k": 1, "tags.v": 1});
+coll.createIndex({point: "2d", "tags.k": 1, "tags.v": 1});
 
 // Succeeds, should be able to look up the complex element
 assert(1 ==
diff --git a/jstests/core/geo_circle3.js b/jstests/core/geo_circle3.js
index 3be564cd180..e931e96783d 100644
--- a/jstests/core/geo_circle3.js
+++ b/jstests/core/geo_circle3.js
@@ -14,7 +14,7 @@ db.places.save({"_id": n++, "loc": {"x": 4.9999, "y": 52.0001}});
 db.places.save({"_id": n++, "loc": {"x": 5.0001, "y": 52.0001}});
 db.places.save({"_id": n++, "loc": {"x": 4.9999, "y": 51.9999}});
 db.places.save({"_id": n++, "loc": {"x": 5.0001, "y": 51.9999}});
-db.places.ensureIndex({loc: "2d"});
+db.places.createIndex({loc: "2d"});
 radius = 0.0001;
 center = [5, 52];
 // print(db.places.find({"loc" : {"$within" : {"$center" : [center, radius]}}}).count())
diff --git a/jstests/core/geo_circle4.js b/jstests/core/geo_circle4.js
index 1feb72a2e48..04ce685db38 100644
--- a/jstests/core/geo_circle4.js
+++ b/jstests/core/geo_circle4.js
@@ -18,7 +18,7 @@ function test(index) {
     db.server848.save({"_id": 8, "loc": {"x": 4.9999, "y": 51.9999}});
     db.server848.save({"_id": 9, "loc": {"x": 5.0001, "y": 51.9999}});
     if (index) {
-        db.server848.ensureIndex({loc: "2d"});
+        db.server848.createIndex({loc: "2d"});
     }
     r = db.server848.find({"loc": {"$within": {"$center": [center, radius]}}}, {_id: 1});
     assert.eq(5, r.count(), "A1");
diff --git a/jstests/core/geo_circle5.js b/jstests/core/geo_circle5.js
index 34b3773ad00..27b973a8ede 100644
--- a/jstests/core/geo_circle5.js
+++ b/jstests/core/geo_circle5.js
@@ -8,7 +8,7 @@ db.server1238.drop();
 db.server1238.remove({});
 db.server1238.save({loc: [5000000, 900000], id: 1});
 db.server1238.save({loc: [5000000, 900000], id: 2});
-db.server1238.ensureIndex({loc: "2d"}, {min: -21000000, max: 21000000});
+db.server1238.createIndex({loc: "2d"}, {min: -21000000, max: 21000000});
 db.server1238.save({loc: [5000000, 900000], id: 3});
 db.server1238.save({loc: [5000000, 900000], id: 4});
 
diff --git a/jstests/core/geo_exactfetch.js b/jstests/core/geo_exactfetch.js
index 68ecc9941ae..93b0b7afcda 100644
--- a/jstests/core/geo_exactfetch.js
+++ b/jstests/core/geo_exactfetch.js
@@ -7,7 +7,7 @@ t.drop();
 
 function test(indexname) {
     assert.eq(1, t.find({lon_lat: [-71.34895, 42.46037]}).itcount(), indexname);
-    t.ensureIndex({lon_lat: indexname, population: -1});
+    t.createIndex({lon_lat: indexname, population: -1});
     assert.eq(2, t.find({lon_lat: {$nearSphere: [-71.34895, 42.46037]}}).itcount(), indexname);
     assert.eq(1, t.find({lon_lat: [-71.34895, 42.46037]}).itcount(), indexname);
     t.dropIndex({lon_lat: indexname, population: -1});
diff --git a/jstests/core/geo_fiddly_box.js b/jstests/core/geo_fiddly_box.js
index 6c2adbe66c6..9f5a9e8d6c4 100644
--- a/jstests/core/geo_fiddly_box.js
+++ b/jstests/core/geo_fiddly_box.js
@@ -11,7 +11,7 @@
 t = db.geo_fiddly_box;
 
 t.drop();
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 t.insert({"loc": [3, 1]});
 t.insert({"loc": [3, 0.5]});
@@ -35,7 +35,7 @@ step = 1;
 numItems = 0;
 
 t.drop();
-t.ensureIndex({loc: "2d"}, {max: max + epsilon / 2, min: min - epsilon / 2});
+t.createIndex({loc: "2d"}, {max: max + epsilon / 2, min: min - epsilon / 2});
 
 for (var x = min; x <= max; x += step) {
     for (var y = min; y <= max; y += step) {
diff --git a/jstests/core/geo_fiddly_box2.js b/jstests/core/geo_fiddly_box2.js
index 6a40b5032b5..a0f87203163 100644
--- a/jstests/core/geo_fiddly_box2.js
+++ b/jstests/core/geo_fiddly_box2.js
@@ -16,18 +16,18 @@ t.insert({"letter": "B", "position": [2, 0]});
 t.insert({"letter": "L", "position": [3, 0]});
 t.insert({"letter": "E", "position": [4, 0]});
 
-t.ensureIndex({position: "2d"});
+t.createIndex({position: "2d"});
 result = t.find({"position": {"$within": {"$box": [[-3, -1], [0, 1]]}}});
 assert.eq(4, result.count());
 
 t.dropIndex({position: "2d"});
-t.ensureIndex({position: "2d"}, {min: -10000000, max: 10000000});
+t.createIndex({position: "2d"}, {min: -10000000, max: 10000000});
 
 result = t.find({"position": {"$within": {"$box": [[-3, -1], [0, 1]]}}});
 assert.eq(4, result.count());
 
 t.dropIndex({position: "2d"});
-t.ensureIndex({position: "2d"}, {min: -1000000000, max: 1000000000});
+t.createIndex({position: "2d"}, {min: -1000000000, max: 1000000000});
 
 result = t.find({"position": {"$within": {"$box": [[-3, -1], [0, 1]]}}});
 assert.eq(4, result.count());
diff --git a/jstests/core/geo_invalid_2d_params.js b/jstests/core/geo_invalid_2d_params.js
index b538d430a66..33419302b47 100644
--- a/jstests/core/geo_invalid_2d_params.js
+++ b/jstests/core/geo_invalid_2d_params.js
@@ -1,8 +1,8 @@
 var t = db.geo_invalid_2d_params;
 t.drop();
 
-assert.commandFailed(t.ensureIndex({loc: "2d"}, {bits: 33}));
-assert.commandFailed(t.ensureIndex({loc: "2d"}, {min: -1, max: -1}));
-assert.commandFailed(t.ensureIndex({loc: "2d"}, {bits: -1}));
-assert.commandFailed(t.ensureIndex({loc: "2d"}, {min: 10, max: 9}));
-assert.commandWorked(t.ensureIndex({loc: "2d"}, {bits: 1, min: -1, max: 1}));
+assert.commandFailed(t.createIndex({loc: "2d"}, {bits: 33}));
+assert.commandFailed(t.createIndex({loc: "2d"}, {min: -1, max: -1}));
+assert.commandFailed(t.createIndex({loc: "2d"}, {bits: -1}));
+assert.commandFailed(t.createIndex({loc: "2d"}, {min: 10, max: 9}));
+assert.commandWorked(t.createIndex({loc: "2d"}, {bits: 1, min: -1, max: 1}));
diff --git a/jstests/core/geo_mindistance.js b/jstests/core/geo_mindistance.js
index 33153e62008..8994892c77d 100644
--- a/jstests/core/geo_mindistance.js
+++ b/jstests/core/geo_mindistance.js
@@ -56,7 +56,7 @@ for (var x = 0; x <= 10; x += 1) {
     }
 }
 
-t.ensureIndex({loc: "2dsphere"});
+t.createIndex({loc: "2dsphere"});
 
 var n_docs = t.count(), geoJSONPoint = {type: 'Point', coordinates: [0, 0]}, legacyPoint = [0, 0];
 
diff --git a/jstests/core/geo_mindistance_boundaries.js b/jstests/core/geo_mindistance_boundaries.js
index 9d556b341ac..7024cfa2ec9 100644
--- a/jstests/core/geo_mindistance_boundaries.js
+++ b/jstests/core/geo_mindistance_boundaries.js
@@ -9,7 +9,7 @@ t.drop();
 t.insert({loc: [1, 0]});  // 1 degree of longitude from origin.
 
 /* $minDistance is supported for 2dsphere index only, not 2d */
-t.ensureIndex({loc: "2dsphere"});
+t.createIndex({loc: "2dsphere"});
 
 //
 // Useful constants.
diff --git a/jstests/core/geo_multikey0.js b/jstests/core/geo_multikey0.js
index 827dd9a41a1..27075a779ee 100644
--- a/jstests/core/geo_multikey0.js
+++ b/jstests/core/geo_multikey0.js
@@ -11,7 +11,7 @@ assert.eq(
 // Check that conflicting constraints are satisfied by parallel array elements with a 2d index on
 // loc.
 if (0) {  // SERVER-3793
-    t.ensureIndex({loc: '2d'});
+    t.createIndex({loc: '2d'});
     assert.eq(
         1,
         t.count({loc: {x: 20, y: 30}, $and: [{loc: {$gt: {x: 20, y: 35}, $lt: {x: 20, y: 34}}}]}));
@@ -26,6 +26,6 @@ assert.eq(1, t.count({loc: [20, 30], x: {$gt: 1.7, $lt: 1.2}}));
 // Check that conflicting constraints are satisfied by parallel array elements of x with a 2d index
 // on loc,x.
 if (0) {  // SERVER-3793
-    t.ensureIndex({loc: '2d', x: 1});
+    t.createIndex({loc: '2d', x: 1});
     assert.eq(1, t.count({loc: [20, 30], x: {$gt: 1.7, $lt: 1.2}}));
 }
diff --git a/jstests/core/geo_multikey1.js b/jstests/core/geo_multikey1.js
index 9c092f4ec31..e6d0ec086da 100644
--- a/jstests/core/geo_multikey1.js
+++ b/jstests/core/geo_multikey1.js
@@ -12,7 +12,7 @@ for (i = 0; i < 10; ++i) {
 t.save({loc: locArr, a: arr, b: arr, c: arr});
 
 // Parallel arrays are allowed for geo indexes.
-assert.commandWorked(t.ensureIndex({loc: '2d', a: 1, b: 1, c: 1}));
+assert.commandWorked(t.createIndex({loc: '2d', a: 1, b: 1, c: 1}));
 
 // Parallel arrays are not allowed for normal indexes.
-assert.commandFailed(t.ensureIndex({loc: 1, a: 1, b: 1, c: 1}));
+assert.commandFailed(t.createIndex({loc: 1, a: 1, b: 1, c: 1}));
diff --git a/jstests/core/geo_multinest0.js b/jstests/core/geo_multinest0.js
index 6c0106d70df..b76c18dbd5c 100644
--- a/jstests/core/geo_multinest0.js
+++ b/jstests/core/geo_multinest0.js
@@ -16,7 +16,7 @@ var res =
     t.insert({zip: "10003", data: [{loc: [30, 30], type: "home"}, {loc: [50, 50], type: "work"}]});
 assert.commandWorked(res);
 
-assert.commandWorked(t.ensureIndex({"data.loc": "2d", zip: 1}));
+assert.commandWorked(t.createIndex({"data.loc": "2d", zip: 1}));
 assert.eq(2, t.getIndexKeys().length);
 
 res =
@@ -41,7 +41,7 @@ t.insert({zip: "10002", data: [{loc: [20, 20], type: "home"}, {loc: [50, 50], ty
 res = t.insert({zip: "10003", data: [{loc: [{x: 30, y: 30}, [50, 50]], type: "home"}]});
 assert(!res.hasWriteError());
 
-assert.commandWorked(t.ensureIndex({"data.loc": "2d", zip: 1}));
+assert.commandWorked(t.createIndex({"data.loc": "2d", zip: 1}));
 assert.eq(2, t.getIndexKeys().length);
 
 res =
diff --git a/jstests/core/geo_multinest1.js b/jstests/core/geo_multinest1.js
index d033cfa86b8..a3fb424829e 100644
--- a/jstests/core/geo_multinest1.js
+++ b/jstests/core/geo_multinest1.js
@@ -16,7 +16,7 @@ var res =
     t.insert({zip: "10003", data: [{loc: [30, 30], type: "home"}, {loc: [49, 49], type: "work"}]});
 assert.commandWorked(res);
 
-assert.commandWorked(t.ensureIndex({"data.loc": "2d", zip: 1}));
+assert.commandWorked(t.createIndex({"data.loc": "2d", zip: 1}));
 assert.eq(2, t.getIndexKeys().length);
 
 res =
diff --git a/jstests/core/geo_near_bounds_overflow.js b/jstests/core/geo_near_bounds_overflow.js
index ff674e89052..1d13d568220 100644
--- a/jstests/core/geo_near_bounds_overflow.js
+++ b/jstests/core/geo_near_bounds_overflow.js
@@ -13,7 +13,7 @@ function testBounds(min, max) {
     // Handle case where either 1. indexLambda will fail but not throw. We are asserting it
     // works, so the outer lambda generates an exception. 2. indexLambda itself will throw.
     const indexLambda = function(t) {
-        return t.ensureIndex({loc: '2d'}, indexBounds);
+        return t.createIndex({loc: '2d'}, indexBounds);
     };
     const assertLambda = function(t, lambda) {
         assert.commandWorked(lambda(t));
diff --git a/jstests/core/geo_near_random1.js b/jstests/core/geo_near_random1.js
index b6350e6c6a7..52dc1e34cbb 100644
--- a/jstests/core/geo_near_random1.js
+++ b/jstests/core/geo_near_random1.js
@@ -34,7 +34,7 @@ test.testPt(test.mkPt(), opts);
 
 // Test $nearSphere with a 2dsphere index
 assert.commandWorked(db.geo_near_random1.dropIndex({loc: '2d'}));
-assert.commandWorked(db.geo_near_random1.ensureIndex({loc: '2dsphere'}));
+assert.commandWorked(db.geo_near_random1.createIndex({loc: '2dsphere'}));
 test.testPt([0, 0], opts);
 test.testPt(test.mkPt(), opts);
 test.testPt(test.mkPt(), opts);
diff --git a/jstests/core/geo_near_random2.js b/jstests/core/geo_near_random2.js
index c524e7a7da4..4ffa95cffae 100644
--- a/jstests/core/geo_near_random2.js
+++ b/jstests/core/geo_near_random2.js
@@ -38,7 +38,7 @@ test.testPt(test.mkPt(0.8), opts);
 
 // Test $nearSphere with 2dsphere index
 assert.commandWorked(db.geo_near_random2.dropIndex({loc: '2d'}));
-assert.commandWorked(db.geo_near_random2.ensureIndex({loc: '2dsphere'}));
+assert.commandWorked(db.geo_near_random2.createIndex({loc: '2dsphere'}));
 test.testPt([0, 0], opts);
 test.testPt(test.mkPt(0.8), opts);
 test.testPt(test.mkPt(0.8), opts);
diff --git a/jstests/core/geo_nearwithin.js b/jstests/core/geo_nearwithin.js
index 37d963b3ddc..6ded21dbd83 100644
--- a/jstests/core/geo_nearwithin.js
+++ b/jstests/core/geo_nearwithin.js
@@ -13,7 +13,7 @@ for (var x = -points; x < points; x += 1) {
     }
 }
 
-assert.commandWorked(t.ensureIndex({geo: "2d"}));
+assert.commandWorked(t.createIndex({geo: "2d"}));
 
 const runQuery = (center) =>
     t.find({$and: [{geo: {$near: [0, 0]}}, {geo: {$within: {$center: center}}}]}).toArray();
diff --git a/jstests/core/geo_oob_sphere.js b/jstests/core/geo_oob_sphere.js
index 3a878f06b78..08a10758c77 100644
--- a/jstests/core/geo_oob_sphere.js
+++ b/jstests/core/geo_oob_sphere.js
@@ -15,7 +15,7 @@ assert.commandWorked(coll.insert({loc: {x: 30, y: 89}}));
 assert.commandWorked(coll.insert({loc: {x: 30, y: 89}}));
 assert.commandWorked(coll.insert({loc: {x: 30, y: 91}}));
 
-assert.commandWorked(coll.ensureIndex({loc: "2d"}));
+assert.commandWorked(coll.createIndex({loc: "2d"}));
 
 assert.throws(function() {
     coll.find({loc: {$nearSphere: [30, 91], $maxDistance: 0.25}}).count();
diff --git a/jstests/core/geo_operator_crs.js b/jstests/core/geo_operator_crs.js
index cab73fedb0f..6118c4efcc7 100644
--- a/jstests/core/geo_operator_crs.js
+++ b/jstests/core/geo_operator_crs.js
@@ -14,7 +14,7 @@ coll.drop();
 // Test 2dsphere index
 //
 
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 
 var legacyZeroPt = [0, 0];
 var jsonZeroPt = {type: "Point", coordinates: [0, 0]};
@@ -42,7 +42,7 @@ assert.commandWorked(coll.dropIndexes());
 // Test 2d Index
 //
 
-assert.commandWorked(coll.ensureIndex({geo: "2d"}));
+assert.commandWorked(coll.createIndex({geo: "2d"}));
 
 assert.commandWorked(coll.insert({geo: legacy90Pt}));
 
@@ -55,7 +55,7 @@ assert.close(result[0].dis, Math.PI / 2);
 // Test with a 2d and 2dsphere index using the aggregation $geoNear stage.
 //
 
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 result = coll.aggregate({$geoNear: {near: jsonZeroPt, distanceField: "dis"}}).toArray();
 assert.close(result[0].dis, (Math.PI / 2) * earthRadiusMeters);
 }());
diff --git a/jstests/core/geo_or.js b/jstests/core/geo_or.js
index 04caca0e106..d571e3ad6e3 100644
--- a/jstests/core/geo_or.js
+++ b/jstests/core/geo_or.js
@@ -15,7 +15,7 @@ t.save({loc: q});
 
 var indexname = "2dsphere";
 
-t.ensureIndex({loc: indexname});
+t.createIndex({loc: indexname});
 
 assert.eq(1, t.find({loc: p}).itcount(), indexname);
 
@@ -87,7 +87,7 @@ t.dropIndexes();
 
 var indexname = "2d";
 
-t.ensureIndex({loc: indexname});
+t.createIndex({loc: indexname});
 
 assert.eq(2,
           t.find({
diff --git a/jstests/core/geo_poly_edge.js b/jstests/core/geo_poly_edge.js
index 971483e9eef..eee43bfc55c 100644
--- a/jstests/core/geo_poly_edge.js
+++ b/jstests/core/geo_poly_edge.js
@@ -8,7 +8,7 @@
 var coll = db.getCollection('jstests_geo_poly_edge');
 coll.drop();
 
-coll.ensureIndex({loc: "2d"});
+coll.createIndex({loc: "2d"});
 
 coll.insert({loc: [10, 10]});
 coll.insert({loc: [10, -10]});
diff --git a/jstests/core/geo_poly_line.js b/jstests/core/geo_poly_line.js
index 3eff8d12496..49e394d140e 100644
--- a/jstests/core/geo_poly_line.js
+++ b/jstests/core/geo_poly_line.js
@@ -12,7 +12,7 @@ t.insert({loc: [2, 0]});
 t.insert({loc: [3, 0]});
 t.insert({loc: [4, 0]});
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 printjson(t.find({loc: {"$within": {"$polygon": [[0, 0], [2, 0], [4, 0]]}}}).toArray());
 
diff --git a/jstests/core/geo_polygon1.js b/jstests/core/geo_polygon1.js
index 34b0cafa1d4..3d6d2ad81b2 100644
--- a/jstests/core/geo_polygon1.js
+++ b/jstests/core/geo_polygon1.js
@@ -13,7 +13,7 @@ for (x = 1; x < 9; x++) {
     }
 }
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 triangle = [[0, 0], [1, 1], [0, 2]];
 
@@ -50,7 +50,7 @@ pacman = [
 ];
 
 t.save({loc: [1, 3]});  // Add a point that's in
-assert.commandWorked(t.ensureIndex({loc: "2d"}));
+assert.commandWorked(t.createIndex({loc: "2d"}));
 
 assert.eq(1, t.find({loc: {$within: {$polygon: pacman}}}).count(), "Pacman single point");
 
diff --git a/jstests/core/geo_polygon2.js b/jstests/core/geo_polygon2.js
index e5dc6d4e941..7a6ad0aedb5 100644
--- a/jstests/core/geo_polygon2.js
+++ b/jstests/core/geo_polygon2.js
@@ -231,7 +231,7 @@ for (var test = 0; test < numTests; test++) {
         }
     }
 
-    var res = t.ensureIndex({loc: "2d"}, {bits: 1 + bits, max: bounds[1], min: bounds[0]});
+    var res = t.createIndex({loc: "2d"}, {bits: 1 + bits, max: bounds[1], min: bounds[0]});
     assert.commandWorked(res);
 
     t.insert({loc: allPointsIn});
diff --git a/jstests/core/geo_queryoptimizer.js b/jstests/core/geo_queryoptimizer.js
index 56653551ba7..17b3c5997f2 100644
--- a/jstests/core/geo_queryoptimizer.js
+++ b/jstests/core/geo_queryoptimizer.js
@@ -6,7 +6,7 @@
 t = db.geo_qo1;
 t.drop();
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 t.insert({'issue': 0});
 t.insert({'issue': 1});
diff --git a/jstests/core/geo_regex0.js b/jstests/core/geo_regex0.js
index 1add7f4e0c3..7629c193ea2 100644
--- a/jstests/core/geo_regex0.js
+++ b/jstests/core/geo_regex0.js
@@ -4,7 +4,7 @@
 t = db.regex0;
 t.drop();
 
-t.ensureIndex({point: '2d', words: 1});
+t.createIndex({point: '2d', words: 1});
 t.insert({point: [1, 1], words: ['foo', 'bar']});
 
 regex = {
diff --git a/jstests/core/geo_s2cursorlimitskip.js b/jstests/core/geo_s2cursorlimitskip.js
index f599ccd5b62..3413314fd27 100644
--- a/jstests/core/geo_s2cursorlimitskip.js
+++ b/jstests/core/geo_s2cursorlimitskip.js
@@ -15,7 +15,7 @@
 var testDB = db.getSiblingDB("geo_s2cursorlimitskip");
 var t = testDB.geo_s2getmmm;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 Random.setRandomSeed();
 var random = Random.rand;
diff --git a/jstests/core/geo_s2dedupnear.js b/jstests/core/geo_s2dedupnear.js
index bbf92ded8d7..0619d307bfa 100644
--- a/jstests/core/geo_s2dedupnear.js
+++ b/jstests/core/geo_s2dedupnear.js
@@ -6,7 +6,7 @@
 t = db.geo_s2dedupnear;
 t.drop();
 
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 var x = {
     "type": "Polygon",
     "coordinates": [[[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]]]
diff --git a/jstests/core/geo_s2descindex.js b/jstests/core/geo_s2descindex.js
index 4a945895c57..c4ebb435a55 100644
--- a/jstests/core/geo_s2descindex.js
+++ b/jstests/core/geo_s2descindex.js
@@ -34,7 +34,7 @@ for (var t = 0; t < descriptors.length; t++) {
     jsTest.log("Trying 2dsphere index with descriptor " + tojson(descriptor));
 
     coll.drop();
-    coll.ensureIndex(descriptor);
+    coll.createIndex(descriptor);
 
     coll.insert(docA);
     coll.insert(docB);
@@ -55,7 +55,7 @@ for (var t = 0; t < descriptors.length; t++) {
 jsTest.log("Trying case found in wild...");
 
 coll.drop();
-coll.ensureIndex({coordinates: "2dsphere", field: -1});
+coll.createIndex({coordinates: "2dsphere", field: -1});
 coll.insert({coordinates: [-118.240013, 34.073893]});
 var query = {
     coordinates: {$geoWithin: {$centerSphere: [[-118.240013, 34.073893], 0.44915760491198753]}},
diff --git a/jstests/core/geo_s2dupe_points.js b/jstests/core/geo_s2dupe_points.js
index 2514cdbf4c1..18550b0bbbb 100644
--- a/jstests/core/geo_s2dupe_points.js
+++ b/jstests/core/geo_s2dupe_points.js
@@ -7,7 +7,7 @@
 // ]
 t = db.geo_s2dupe_points;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 function testDuplicates(shapeName, shapeWithDupes, shapeWithoutDupes) {
     // insert a doc with dupes
diff --git a/jstests/core/geo_s2edgecases.js b/jstests/core/geo_s2edgecases.js
index 3dabfdf0bcb..6e4633f58c8 100644
--- a/jstests/core/geo_s2edgecases.js
+++ b/jstests/core/geo_s2edgecases.js
@@ -51,7 +51,7 @@ penguin2 = {
 };
 t.insert({geo: penguin2});
 
-t.ensureIndex({geo: "2dsphere", nonGeo: 1});
+t.createIndex({geo: "2dsphere", nonGeo: 1});
 
 res = t.find({"geo": {"$geoIntersects": {"$geometry": roundworldpoint}}});
 assert.eq(res.count(), 2);
diff --git a/jstests/core/geo_s2exact.js b/jstests/core/geo_s2exact.js
index 2c8571c0830..92ce551d873 100644
--- a/jstests/core/geo_s2exact.js
+++ b/jstests/core/geo_s2exact.js
@@ -5,7 +5,7 @@ t.drop();
 function test(geometry) {
     t.insert({geo: geometry});
     assert.eq(1, t.find({geo: geometry}).itcount(), tojson(geometry));
-    t.ensureIndex({geo: "2dsphere"});
+    t.createIndex({geo: "2dsphere"});
     assert.eq(1, t.find({geo: geometry}).itcount(), tojson(geometry));
     t.dropIndex({geo: "2dsphere"});
 }
diff --git a/jstests/core/geo_s2explain.js b/jstests/core/geo_s2explain.js
index 842c6eb22c8..9ae76163485 100644
--- a/jstests/core/geo_s2explain.js
+++ b/jstests/core/geo_s2explain.js
@@ -11,7 +11,7 @@ var point1 = {loc: {type: "Point", coordinates: [10, 10]}};
 var point2 = {loc: {type: "Point", coordinates: [10.001, 10]}};
 assert.commandWorked(t.insert([point1, point2]));
 
-assert.commandWorked(t.ensureIndex({loc: "2dsphere"}));
+assert.commandWorked(t.createIndex({loc: "2dsphere"}));
 
 var explain = t.find({loc: {$nearSphere: {type: "Point", coordinates: [10, 10]}}})
                   .limit(1)
diff --git a/jstests/core/geo_s2holesameasshell.js b/jstests/core/geo_s2holesameasshell.js
index 5407fe45c26..0b3f8ea35ec 100644
--- a/jstests/core/geo_s2holesameasshell.js
+++ b/jstests/core/geo_s2holesameasshell.js
@@ -1,7 +1,7 @@
 // If polygons have holes, the holes cannot be equal to the entire geometry.
 var t = db.geo_s2holessameasshell;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 var centerPoint = {"type": "Point", "coordinates": [0.5, 0.5]};
 var edgePoint = {"type": "Point", "coordinates": [0, 0.5]};
diff --git a/jstests/core/geo_s2index.js b/jstests/core/geo_s2index.js
index ecc20c7e637..328b43d04ab 100644
--- a/jstests/core/geo_s2index.js
+++ b/jstests/core/geo_s2index.js
@@ -10,7 +10,7 @@ someline = {
     "coordinates": [[40, 5], [40, 5], [40, 5], [41, 6], [41, 6]]
 };
 t.insert({geo: someline, nonGeo: "someline"});
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 foo = t.find({geo: {$geoIntersects: {$geometry: {type: "Point", coordinates: [40, 5]}}}}).next();
 assert.eq(foo.geo, someline);
 t.dropIndex({geo: "2dsphere"});
@@ -56,7 +56,7 @@ somepoly = {
 };
 t.insert({geo: somepoly, nonGeo: "somepoly"});
 
-var res = t.ensureIndex({geo: "2dsphere", nonGeo: 1});
+var res = t.createIndex({geo: "2dsphere", nonGeo: 1});
 // We have a point without any geo data.  Don't error.
 assert.commandWorked(res);
 
@@ -86,7 +86,7 @@ assert.eq(res.itcount(), 1);
 
 // Don't crash mongod if we give it bad input.
 t.drop();
-t.ensureIndex({loc: "2dsphere", x: 1});
+t.createIndex({loc: "2dsphere", x: 1});
 t.save({loc: [0, 0]});
 assert.throws(function() {
     return t.count({loc: {$foo: [0, 0]}});
@@ -102,7 +102,7 @@ assert.throws(function() {
 
 // If we specify a datum, it has to be valid (WGS84).
 t.drop();
-t.ensureIndex({loc: "2dsphere"});
+t.createIndex({loc: "2dsphere"});
 res = t.insert({
     loc: {type: 'Point', coordinates: [40, 5], crs: {type: 'name', properties: {name: 'EPSG:2000'}}}
 });
@@ -127,36 +127,36 @@ assert.commandWorked(res);
 // 0 <= coarsestIndexedLevel <= finestIndexedLevel <= 30.
 t.drop();
 t.save({loc: [0, 0]});
-res = t.ensureIndex({loc: "2dsphere"}, {finestIndexedLevel: 17, coarsestIndexedLevel: 5});
+res = t.createIndex({loc: "2dsphere"}, {finestIndexedLevel: 17, coarsestIndexedLevel: 5});
 assert.commandWorked(res);
 // Ensure the index actually works at a basic level
 assert.neq(null, t.findOne({loc: {$geoNear: {$geometry: {type: 'Point', coordinates: [0, 0]}}}}));
 
 t.drop();
 t.save({loc: [0, 0]});
-res = t.ensureIndex({loc: "2dsphere"}, {finestIndexedLevel: 31, coarsestIndexedLevel: 5});
+res = t.createIndex({loc: "2dsphere"}, {finestIndexedLevel: 31, coarsestIndexedLevel: 5});
 assert.commandFailed(res);
 
 t.drop();
 t.save({loc: [0, 0]});
-res = t.ensureIndex({loc: "2dsphere"}, {finestIndexedLevel: 30, coarsestIndexedLevel: 0});
+res = t.createIndex({loc: "2dsphere"}, {finestIndexedLevel: 30, coarsestIndexedLevel: 0});
 assert.commandWorked(res);
 // Ensure the index actually works at a basic level
 assert.neq(null, t.findOne({loc: {$geoNear: {$geometry: {type: 'Point', coordinates: [0, 0]}}}}));
 
 t.drop();
 t.save({loc: [0, 0]});
-res = t.ensureIndex({loc: "2dsphere"}, {finestIndexedLevel: 30, coarsestIndexedLevel: -1});
+res = t.createIndex({loc: "2dsphere"}, {finestIndexedLevel: 30, coarsestIndexedLevel: -1});
 assert.commandFailed(res);
 
 // SERVER-21491 Verify that 2dsphere index options require correct types.
-res = t.ensureIndex({loc: '2dsphere'}, {'2dsphereIndexVersion': 'NOT_A_NUMBER'});
+res = t.createIndex({loc: '2dsphere'}, {'2dsphereIndexVersion': 'NOT_A_NUMBER'});
 assert.commandFailed(res);
 
-res = t.ensureIndex({loc: '2dsphere'}, {finestIndexedLevel: 'NOT_A_NUMBER'});
+res = t.createIndex({loc: '2dsphere'}, {finestIndexedLevel: 'NOT_A_NUMBER'});
 assert.commandFailedWithCode(res, ErrorCodes.TypeMismatch);
 
-res = t.ensureIndex({loc: '2dsphere'}, {coarsestIndexedLevel: 'NOT_A_NUMBER'});
+res = t.createIndex({loc: '2dsphere'}, {coarsestIndexedLevel: 'NOT_A_NUMBER'});
 assert.commandFailedWithCode(res, ErrorCodes.TypeMismatch);
 
 // Ensure polygon which previously triggered an assertion error in SERVER-19674
diff --git a/jstests/core/geo_s2indexoldformat.js b/jstests/core/geo_s2indexoldformat.js
index 43974f695cb..ffe472464d4 100644
--- a/jstests/core/geo_s2indexoldformat.js
+++ b/jstests/core/geo_s2indexoldformat.js
@@ -9,7 +9,7 @@ t.insert({geo: [41, 6], nonGeo: ["pointB"]});
 t.insert({geo: [41, 6]});
 t.insert({geo: {x: 40.6, y: 5.4}});
 
-t.ensureIndex({geo: "2dsphere", nonGeo: 1});
+t.createIndex({geo: "2dsphere", nonGeo: 1});
 
 res = t.find({"geo": {"$geoIntersects": {"$geometry": {x: 40, y: 5}}}});
 assert.eq(res.count(), 1);
diff --git a/jstests/core/geo_s2indexversion1.js b/jstests/core/geo_s2indexversion1.js
index a06670ab220..2df90bb1235 100644
--- a/jstests/core/geo_s2indexversion1.js
+++ b/jstests/core/geo_s2indexversion1.js
@@ -15,27 +15,27 @@ coll.drop();
 //
 
 var res;
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": -1});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": -1});
 assert.commandFailed(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 0});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 0});
 assert.commandFailed(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 4});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 4});
 assert.commandFailed(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": Infinity});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": Infinity});
 assert.commandFailed(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": "foo"});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": "foo"});
 assert.commandFailed(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": {a: 1}});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": {a: 1}});
 assert.commandFailed(res);
 coll.drop();
 
@@ -43,31 +43,31 @@ coll.drop();
 // Index build should succeed for valid values of "2dsphereIndexVersion".
 //
 
-res = coll.ensureIndex({geo: "2dsphere"});
+res = coll.createIndex({geo: "2dsphere"});
 assert.commandWorked(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1});
 assert.commandWorked(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberInt(1)});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberInt(1)});
 assert.commandWorked(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberLong(1)});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberLong(1)});
 assert.commandWorked(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2});
 assert.commandWorked(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberInt(2)});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberInt(2)});
 assert.commandWorked(res);
 coll.drop();
 
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberLong(2)});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": NumberLong(2)});
 assert.commandWorked(res);
 coll.drop();
 
@@ -75,7 +75,7 @@ coll.drop();
 // {2dsphereIndexVersion: 3} should be the default for new indexes.
 //
 
-res = coll.ensureIndex({geo: "2dsphere"});
+res = coll.createIndex({geo: "2dsphere"});
 assert.commandWorked(res);
 var specObj = coll.getIndexes().filter(function(z) {
     return z.name == "geo_2dsphere";
@@ -85,26 +85,26 @@ coll.drop();
 
 //
 // Two index specs are considered equivalent if they differ only in '2dsphereIndexVersion', and
-// ensureIndex() should become a no-op on repeated requests that only differ in this way.
+// createIndex() should become a no-op on repeated requests that only differ in this way.
 //
 
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
 assert.eq(1, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 assert.eq(2, coll.getIndexes().length);
 coll.drop();
 
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
 assert.eq(1, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1}));
 assert.eq(2, coll.getIndexes().length);
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere"}));
 assert.eq(2, coll.getIndexes().length);
 coll.drop();
 
@@ -175,7 +175,7 @@ var geometryCollectionDoc = {
 };
 
 // {2dsphereIndexVersion: 2} indexes allow all supported GeoJSON objects.
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 2});
 assert.commandWorked(res);
 res = coll.insert(pointDoc);
 assert.commandWorked(res);
@@ -194,7 +194,7 @@ assert.commandWorked(res);
 coll.drop();
 
 // {2dsphereIndexVersion: 1} indexes allow only Point, LineString, and Polygon.
-res = coll.ensureIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1});
+res = coll.createIndex({geo: "2dsphere"}, {"2dsphereIndexVersion": 1});
 assert.commandWorked(res);
 res = coll.insert(pointDoc);
 assert.commandWorked(res);
diff --git a/jstests/core/geo_s2intersection.js b/jstests/core/geo_s2intersection.js
index 25479a58349..50f26a6aa83 100644
--- a/jstests/core/geo_s2intersection.js
+++ b/jstests/core/geo_s2intersection.js
@@ -1,6 +1,6 @@
 var t = db.geo_s2intersectinglines;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 /**All the tests in this file are generally confirming intersections based upon
  * these three geo objects.
@@ -143,7 +143,7 @@ assert.eq(result[0]['name'], 'canonPoly');
 // Case 12: Make sure that we properly handle and $and of two
 // $geoIntersects predicates.
 t.drop();
-t.ensureIndex({a: "2dsphere"});
+t.createIndex({a: "2dsphere"});
 t.insert({a: {type: "Polygon", coordinates: [[[0, 0], [3, 6], [6, 0], [0, 0]]]}});
 
 var firstPoint = {$geometry: {type: "Point", coordinates: [3.0, 1.0]}};
diff --git a/jstests/core/geo_s2largewithin.js b/jstests/core/geo_s2largewithin.js
index 4723bb4833e..156b711bdff 100644
--- a/jstests/core/geo_s2largewithin.js
+++ b/jstests/core/geo_s2largewithin.js
@@ -5,7 +5,7 @@
 // ]
 t = db.geo_s2largewithin;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 testPoint = {
     name: "origin",
diff --git a/jstests/core/geo_s2meridian.js b/jstests/core/geo_s2meridian.js
index 47f4fb08a6a..5842000e998 100644
--- a/jstests/core/geo_s2meridian.js
+++ b/jstests/core/geo_s2meridian.js
@@ -1,6 +1,6 @@
 t = db.geo_s2meridian;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 /**
  * Test 1: check that intersection works on the meridian.  We insert a line
@@ -26,7 +26,7 @@ result = t.find({geo: {$geoIntersects: {$geometry: lineAlongMeridian}}});
 assert.eq(result.itcount(), 1);
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 /*
  * Test 2: check that within work across the meridian.  We insert points
  * on the meridian, and immediately on either side, and confirm that a poly
@@ -55,7 +55,7 @@ result = t.find({geo: {$geoWithin: {$geometry: meridianCrossingPoly}}});
 assert.eq(result.itcount(), 3);
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 /*
  * Test 3: Check that near works around the meridian.  Insert two points, one
  * closer, but across the meridian, and confirm they both come back, and
diff --git a/jstests/core/geo_s2multi.js b/jstests/core/geo_s2multi.js
index 28034ad8ba6..9f4208d51aa 100644
--- a/jstests/core/geo_s2multi.js
+++ b/jstests/core/geo_s2multi.js
@@ -1,7 +1,7 @@
 t = db.geo_s2multi;
 t.drop();
 
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 // Let's try the examples in the GeoJSON spec.
 // @tags: [
diff --git a/jstests/core/geo_s2near.js b/jstests/core/geo_s2near.js
index c61e16927ff..2cd1df5cbbc 100644
--- a/jstests/core/geo_s2near.js
+++ b/jstests/core/geo_s2near.js
@@ -14,7 +14,7 @@ goldenPoint = {
     coordinates: [31.0, 41.0]
 };
 t.insert({geo: goldenPoint});
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 resNear =
     t.aggregate([
          {$geoNear: {near: [30, 40], distanceField: "d", spherical: true, includeLocs: "loc"}},
@@ -40,7 +40,7 @@ origin = {
     "coordinates": [lng, lat]
 };
 
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 // Near only works when the query is a point.
 someline = {
diff --git a/jstests/core/geo_s2nearComplex.js b/jstests/core/geo_s2nearComplex.js
index d7f4fffabc1..40bc9b72445 100644
--- a/jstests/core/geo_s2nearComplex.js
+++ b/jstests/core/geo_s2nearComplex.js
@@ -6,7 +6,7 @@
 
 var t = db.get_s2nearcomplex;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 /* Short names for math operations */
 Random.setRandomSeed();
@@ -176,7 +176,7 @@ print("Total points:");
 print(t.find(query).itcount());
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 // Test a uniform distribution with 5 gaps each with 10 points missing.
 uniformPointsWithGaps(origin, 1000, 1, 10.0, 5, 10);
 
@@ -188,7 +188,7 @@ print("Total points:");
 print(t.find(query).itcount());
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 // Test a uniform distribution with 5 clusters each with between 10 and 100 points.
 uniformPointsWithClusters(origin, 1000, 1, 10.0, 5, 10, 100);
@@ -201,7 +201,7 @@ print("Total points:");
 print(t.find(query).itcount());
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 // Test a uniform near search with origin around the pole.
 
@@ -225,7 +225,7 @@ print(t.find({geo: {$geoNear: {$geometry: originGeo}}})
 assert.eq(t.find({geo: {$geoNear: {$geometry: originGeo}}}).itcount(), 50);
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 // Center point near the meridian
 originGeo = {
@@ -247,7 +247,7 @@ print(t.find({geo: {$geoNear: {$geometry: originGeo}}})
 assert.eq(t.find({geo: {$geoNear: {$geometry: originGeo}}}).itcount(), 50);
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 // Center point near the negative meridian
 originGeo = {
@@ -270,7 +270,7 @@ assert.eq(t.find({geo: {$near: {$geometry: originGeo}}}).itcount(), 50);
 
 // Near search with points that are really far away.
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 originGeo = {
     type: "Point",
     coordinates: [0.0, 0.0]
diff --git a/jstests/core/geo_s2near_equator_opposite.js b/jstests/core/geo_s2near_equator_opposite.js
index de196ea70eb..4b028baf43c 100644
--- a/jstests/core/geo_s2near_equator_opposite.js
+++ b/jstests/core/geo_s2near_equator_opposite.js
@@ -12,7 +12,7 @@ t.drop();
 t.insert({loc: {type: 'Point', coordinates: [0, 0]}});
 t.insert({loc: {type: 'Point', coordinates: [-1, 0]}});
 
-t.ensureIndex({loc: '2dsphere'});
+t.createIndex({loc: '2dsphere'});
 
 // upper bound for half of earth's circumference in meters
 var dist = 40075000 / 2 + 1;
diff --git a/jstests/core/geo_s2nearcorrect.js b/jstests/core/geo_s2nearcorrect.js
index 54552a4bee5..80ece4223d2 100644
--- a/jstests/core/geo_s2nearcorrect.js
+++ b/jstests/core/geo_s2nearcorrect.js
@@ -10,7 +10,7 @@ longline = {
     "coordinates": [[0, 0], [179, 89]]
 };
 t.insert({geo: longline});
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 origin = {
     "type": "Point",
     "coordinates": [45, 45]
diff --git a/jstests/core/geo_s2nearwithin.js b/jstests/core/geo_s2nearwithin.js
index 8018dfec575..eb334e89aff 100644
--- a/jstests/core/geo_s2nearwithin.js
+++ b/jstests/core/geo_s2nearwithin.js
@@ -18,7 +18,7 @@ origin = {
     "coordinates": [0, 0]
 };
 
-assert.commandWorked(t.ensureIndex({geo: "2dsphere"}));
+assert.commandWorked(t.createIndex({geo: "2dsphere"}));
 // Near requires an index, and 2dsphere is an index.  Spherical isn't
 // specified so this doesn't work.
 let res = assert.commandFailedWithCode(t.runCommand("aggregate", {
diff --git a/jstests/core/geo_s2nongeoarray.js b/jstests/core/geo_s2nongeoarray.js
index 4242a9f38e9..5fb5c59f1af 100644
--- a/jstests/core/geo_s2nongeoarray.js
+++ b/jstests/core/geo_s2nongeoarray.js
@@ -11,19 +11,19 @@ var data = {geo: oldPoint, nonGeo: [123, 456], otherNonGeo: [{b: [1, 2]}, {b: [3
 
 t.drop();
 assert.commandWorked(t.insert(data));
-assert.commandWorked(t.ensureIndex({otherNonGeo: 1}));
+assert.commandWorked(t.createIndex({otherNonGeo: 1}));
 assert.eq(1, t.find({otherNonGeo: {b: [1, 2]}}).itcount());
 assert.eq(0, t.find({otherNonGeo: 1}).itcount());
 assert.eq(1, t.find({'otherNonGeo.b': 1}).itcount());
 
 t.drop();
 t.insert(data);
-t.ensureIndex({geo: "2d", nonGeo: 1, otherNonGeo: 1});
+t.createIndex({geo: "2d", nonGeo: 1, otherNonGeo: 1});
 assert.eq(t.find({nonGeo: 123, geo: {$nearSphere: oldPoint}}).itcount(), 1);
 assert.eq(t.find({'otherNonGeo.b': 1, geo: {$nearSphere: oldPoint}}).itcount(), 1);
 
 t.drop();
 t.insert(data);
-t.ensureIndex({geo: "2dsphere", nonGeo: 1, otherNonGeo: 1});
+t.createIndex({geo: "2dsphere", nonGeo: 1, otherNonGeo: 1});
 assert.eq(t.find({nonGeo: 123, geo: {$nearSphere: oldPoint}}).itcount(), 1);
 assert.eq(t.find({'otherNonGeo.b': 1, geo: {$nearSphere: oldPoint}}).itcount(), 1);
diff --git a/jstests/core/geo_s2nonstring.js b/jstests/core/geo_s2nonstring.js
index 960f0c727a8..a76a7cd073e 100644
--- a/jstests/core/geo_s2nonstring.js
+++ b/jstests/core/geo_s2nonstring.js
@@ -2,13 +2,13 @@
 t = db.geo_s2nonstring;
 t.drop();
 
-t.ensureIndex({geo: '2dsphere', x: 1});
+t.createIndex({geo: '2dsphere', x: 1});
 
 t.save({geo: {type: 'Point', coordinates: [0, 0]}, x: 'a'});
 t.save({geo: {type: 'Point', coordinates: [0, 0]}, x: 5});
 
 t.drop();
-t.ensureIndex({geo: '2dsphere', x: 1});
+t.createIndex({geo: '2dsphere', x: 1});
 
 t.save({geo: {type: 'Point', coordinates: [0, 0]}, x: 'a'});
 t.save({geo: {type: 'Point', coordinates: [0, 0]}});
diff --git a/jstests/core/geo_s2nopoints.js b/jstests/core/geo_s2nopoints.js
index 0d2afdb1672..7b3a3b970a7 100644
--- a/jstests/core/geo_s2nopoints.js
+++ b/jstests/core/geo_s2nopoints.js
@@ -2,7 +2,7 @@
 t = db.geo_s2nopoints;
 t.drop();
 
-t.ensureIndex({loc: "2dsphere", x: 1});
+t.createIndex({loc: "2dsphere", x: 1});
 assert.eq(
     0,
     t.count({loc: {$near: {$geometry: {type: 'Point', coordinates: [0, 0]}, $maxDistance: 10}}}));
diff --git a/jstests/core/geo_s2oddshapes.js b/jstests/core/geo_s2oddshapes.js
index 0cc60a661a4..9ebe6be7ed3 100644
--- a/jstests/core/geo_s2oddshapes.js
+++ b/jstests/core/geo_s2oddshapes.js
@@ -6,7 +6,7 @@
 // ]
 var t = db.geo_s2oddshapes;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 var testPoint = {name: "origin", geo: {type: "Point", coordinates: [0.0, 0.0]}};
 
@@ -58,7 +58,7 @@ assert.eq(result.itcount(), 3);
 // Test a poly that is the size of half the earth.
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 var insidePoint = {name: "inside", geo: {type: "Point", name: "inside", coordinates: [100.0, 0.0]}};
 
@@ -84,7 +84,7 @@ assert.eq(point.name, 'inside');
 // Test a poly that is very small.  A couple meters around.
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 insidePoint = {
     name: "inside",
diff --git a/jstests/core/geo_s2ordering.js b/jstests/core/geo_s2ordering.js
index 8ef84905b75..9e53cafb981 100644
--- a/jstests/core/geo_s2ordering.js
+++ b/jstests/core/geo_s2ordering.js
@@ -35,7 +35,7 @@ function makepoints(needle) {
 }
 
 function runTest(index) {
-    assert.commandWorked(coll.ensureIndex(index));
+    assert.commandWorked(coll.createIndex(index));
     const cursor =
         coll.find({nongeo: needle, geo: {$within: {$centerSphere: [[0, 0], Math.PI / 180.0]}}});
     const stats = cursor.explain("executionStats").executionStats;
diff --git a/jstests/core/geo_s2overlappingpolys.js b/jstests/core/geo_s2overlappingpolys.js
index 9dd7125349a..3cc1f254a37 100644
--- a/jstests/core/geo_s2overlappingpolys.js
+++ b/jstests/core/geo_s2overlappingpolys.js
@@ -6,7 +6,7 @@
 var t = db.geo_s2overlappingpolys;
 t.drop();
 
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 var minError = 0.8e-13;
 
diff --git a/jstests/core/geo_s2polywithholes.js b/jstests/core/geo_s2polywithholes.js
index c20da5a34aa..e37606465f6 100644
--- a/jstests/core/geo_s2polywithholes.js
+++ b/jstests/core/geo_s2polywithholes.js
@@ -5,7 +5,7 @@
  */
 var t = db.geo_s2weirdpolys;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 var centerPoint = {"type": "Point", "coordinates": [0.5, 0.5]};
 var edgePoint = {"type": "Point", "coordinates": [0, 0.5]};
diff --git a/jstests/core/geo_s2selfintersectingpoly.js b/jstests/core/geo_s2selfintersectingpoly.js
index 0887f850fe3..0ac522fa6f7 100644
--- a/jstests/core/geo_s2selfintersectingpoly.js
+++ b/jstests/core/geo_s2selfintersectingpoly.js
@@ -1,6 +1,6 @@
 var t = db.geo_s2selfintersectingpoly;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 var intersectingPolygon = {
     "type": "Polygon",
diff --git a/jstests/core/geo_s2sparse.js b/jstests/core/geo_s2sparse.js
index d058afb9f9b..1a9a3b67b9b 100644
--- a/jstests/core/geo_s2sparse.js
+++ b/jstests/core/geo_s2sparse.js
@@ -15,7 +15,7 @@ var indexName = 'geo_2dsphere_nonGeo_1';
 
 // Clean up.
 coll.drop();
-coll.ensureIndex(indexSpec);
+coll.createIndex(indexSpec);
 
 var bulkInsertDocs = function(coll, numDocs, makeDocFn) {
     print("Bulk inserting " + numDocs + " documents");
@@ -77,7 +77,7 @@ assert.eq(N + N, coll.validate().keysPerIndex[indexName]);
 //
 
 coll.drop();
-coll.ensureIndex(indexSpec, {"2dsphereIndexVersion": 1});
+coll.createIndex(indexSpec, {"2dsphereIndexVersion": 1});
 
 // Insert N documents with the geo field.
 bulkInsertDocs(coll, N, function(i) {
@@ -101,7 +101,7 @@ assert.eq(N + N, coll.validate().keysPerIndex[indexName]);
 
 // Clean up.
 coll.drop();
-coll.ensureIndex({geo: "2dsphere", otherGeo: "2dsphere"});
+coll.createIndex({geo: "2dsphere", otherGeo: "2dsphere"});
 
 indexName = 'geo_2dsphere_otherGeo_2dsphere';
 
diff --git a/jstests/core/geo_s2twofields.js b/jstests/core/geo_s2twofields.js
index 73666f2bf5e..160b5f513e1 100644
--- a/jstests/core/geo_s2twofields.js
+++ b/jstests/core/geo_s2twofields.js
@@ -55,7 +55,7 @@ function timeWithoutAndWithAnIndex(index, query) {
     var withoutTime = semiRigorousTime(function() {
         return t.find(query).explain("executionStats").executionStats.executionTimeMillis;
     });
-    t.ensureIndex(index);
+    t.createIndex(index);
     var withTime = semiRigorousTime(function() {
         return t.find(query).explain("executionStats").executionStats.executionTimeMillis;
     });
diff --git a/jstests/core/geo_s2validindex.js b/jstests/core/geo_s2validindex.js
index 4c024d2d585..444346def14 100644
--- a/jstests/core/geo_s2validindex.js
+++ b/jstests/core/geo_s2validindex.js
@@ -6,19 +6,19 @@ var coll = db.getCollection("twodspherevalid");
 
 // Valid index
 coll.drop();
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere", other: 1}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere", other: 1}));
 
 // Valid index
 coll.drop();
-assert.commandWorked(coll.ensureIndex({geo: "2dsphere", other: 1, geo2: "2dsphere"}));
+assert.commandWorked(coll.createIndex({geo: "2dsphere", other: 1, geo2: "2dsphere"}));
 
 // Invalid index, using hash with 2dsphere
 coll.drop();
-assert.commandFailed(coll.ensureIndex({geo: "2dsphere", other: "hash"}));
+assert.commandFailed(coll.createIndex({geo: "2dsphere", other: "hash"}));
 
 // Invalid index, using 2d with 2dsphere
 coll.drop();
-assert.commandFailed(coll.ensureIndex({geo: "2dsphere", other: "2d"}));
+assert.commandFailed(coll.createIndex({geo: "2dsphere", other: "2d"}));
 
 jsTest.log("Success!");
 
diff --git a/jstests/core/geo_s2within.js b/jstests/core/geo_s2within.js
index c32eb4fd612..4f908a4f303 100644
--- a/jstests/core/geo_s2within.js
+++ b/jstests/core/geo_s2within.js
@@ -4,7 +4,7 @@
 // ]
 t = db.geo_s2within;
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 
 somepoly = {
     "type": "Polygon",
@@ -19,7 +19,7 @@ res = t.find({"geo": {"$within": {"$geometry": somepoly}}});
 assert.eq(res.itcount(), 1);
 
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 somepoly = {
     "type": "Polygon",
     "coordinates": [
diff --git a/jstests/core/geo_small_large.js b/jstests/core/geo_small_large.js
index 5cfa3e68e0f..94d5298081e 100644
--- a/jstests/core/geo_small_large.js
+++ b/jstests/core/geo_small_large.js
@@ -56,7 +56,7 @@ for (var i = 0; i < scales.length; i++) {
 
     var t = db["geo_small_large"];
     t.drop();
-    t.ensureIndex({p: "2d"}, {min: min, max: max, bits: bits});
+    t.createIndex({p: "2d"}, {min: min, max: max, bits: bits});
 
     var outPoints = 0;
     var inPoints = 0;
diff --git a/jstests/core/geo_sort1.js b/jstests/core/geo_sort1.js
index 22e185d0106..3e9ee494812 100644
--- a/jstests/core/geo_sort1.js
+++ b/jstests/core/geo_sort1.js
@@ -12,7 +12,7 @@ for (x = 0; x < 10; x++) {
     }
 }
 
-t.ensureIndex({loc: "2d", foo: 1});
+t.createIndex({loc: "2d", foo: 1});
 
 q = t.find({loc: {$near: [5, 5]}, foo: {$gt: 20}});
 m = function(z) {
diff --git a/jstests/core/geo_uniqueDocs.js b/jstests/core/geo_uniqueDocs.js
index 88162e42498..b6eaf4e0501 100644
--- a/jstests/core/geo_uniqueDocs.js
+++ b/jstests/core/geo_uniqueDocs.js
@@ -11,7 +11,7 @@ t.drop();
 assert.commandWorked(t.save({locs: [[0, 2], [3, 4]]}));
 assert.commandWorked(t.save({locs: [[6, 8], [10, 10]]}));
 
-assert.commandWorked(t.ensureIndex({locs: '2d'}));
+assert.commandWorked(t.createIndex({locs: '2d'}));
 
 // $geoNear tests
 // uniqueDocs option is ignored.
diff --git a/jstests/core/geo_uniqueDocs2.js b/jstests/core/geo_uniqueDocs2.js
index 9e0b4a0a284..1486023b73f 100644
--- a/jstests/core/geo_uniqueDocs2.js
+++ b/jstests/core/geo_uniqueDocs2.js
@@ -12,7 +12,7 @@ t = db[collName];
 t.drop();
 
 t.save({loc: [[20, 30], [40, 50]]});
-t.ensureIndex({loc: '2d'});
+t.createIndex({loc: '2d'});
 
 // Check exact matches of different locations.
 assert.eq(1, t.count({loc: [20, 30]}));
@@ -109,5 +109,5 @@ for (i = 0; i < 10000; ++i) {
 }
 arr.push([100, 100]);
 t.save({loc: arr});
-t.ensureIndex({loc: '2d'});
+t.createIndex({loc: '2d'});
 assert.eq(1, t.count({loc: {$within: {$center: [[99, 99], 5]}}}));
diff --git a/jstests/core/geo_update.js b/jstests/core/geo_update.js
index 21cf42d2208..015e56e34a5 100644
--- a/jstests/core/geo_update.js
+++ b/jstests/core/geo_update.js
@@ -11,7 +11,7 @@
 var coll = db.testGeoUpdate;
 coll.drop();
 
-coll.ensureIndex({loc: "2d"});
+coll.createIndex({loc: "2d"});
 
 // Test normal update
 print("Updating...");
diff --git a/jstests/core/geo_update1.js b/jstests/core/geo_update1.js
index a4de04fbd93..cd23e65b7b7 100644
--- a/jstests/core/geo_update1.js
+++ b/jstests/core/geo_update1.js
@@ -11,7 +11,7 @@ for (var x = 0; x < 10; x++) {
     }
 }
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 function p() {
     print("--------------");
diff --git a/jstests/core/geo_update2.js b/jstests/core/geo_update2.js
index f1b94925cb7..d67b3a9bcc1 100644
--- a/jstests/core/geo_update2.js
+++ b/jstests/core/geo_update2.js
@@ -11,7 +11,7 @@ for (var x = 0; x < 10; x++) {
     }
 }
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 function p() {
     print("--------------");
diff --git a/jstests/core/geo_update_btree.js b/jstests/core/geo_update_btree.js
index 8cf711a9e48..7a58362fe18 100644
--- a/jstests/core/geo_update_btree.js
+++ b/jstests/core/geo_update_btree.js
@@ -10,7 +10,7 @@
 var coll = db.getCollection("jstests_geo_update_btree");
 coll.drop();
 
-coll.ensureIndex({loc: '2d'});
+coll.createIndex({loc: '2d'});
 
 var big = new Array(3000).toString();
 
diff --git a/jstests/core/geo_update_btree2.js b/jstests/core/geo_update_btree2.js
index 3bc0a7c9760..e37dbb190e1 100644
--- a/jstests/core/geo_update_btree2.js
+++ b/jstests/core/geo_update_btree2.js
@@ -28,7 +28,7 @@ var status = function(msg) {
 var coll = db.getCollection("jstests_geo_update_btree2");
 coll.drop();
 
-coll.ensureIndex({loc: '2d'});
+coll.createIndex({loc: '2d'});
 
 status("Inserting points...");
 
diff --git a/jstests/core/geo_update_dedup.js b/jstests/core/geo_update_dedup.js
index 34e9aff30dd..3938204c70e 100644
--- a/jstests/core/geo_update_dedup.js
+++ b/jstests/core/geo_update_dedup.js
@@ -13,7 +13,7 @@ var t = db.jstests_geo_update_dedup;
 
 // 2d index with $near
 t.drop();
-t.ensureIndex({locs: "2d"});
+t.createIndex({locs: "2d"});
 t.save({locs: [[49.999, 49.999], [50.0, 50.0], [50.001, 50.001]]});
 
 var q = {locs: {$near: [50.0, 50.0]}};
@@ -24,7 +24,7 @@ assert.eq(1, res.nMatched);
 assert.eq(1, t.findOne().touchCount);
 
 t.drop();
-t.ensureIndex({locs: "2d"});
+t.createIndex({locs: "2d"});
 t.save({locs: [{x: 49.999, y: 49.999}, {x: 50.0, y: 50.0}, {x: 50.001, y: 50.001}]});
 res = t.update({locs: {$near: {x: 50.0, y: 50.0}}}, {$inc: {touchCount: 1}});
 assert.eq(1, res.nMatched);
@@ -32,7 +32,7 @@ assert.eq(1, t.findOne().touchCount);
 
 // 2d index with $within
 t.drop();
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 t.save({loc: [[0, 0], [1, 1]]});
 
 res = t.update({loc: {$within: {$center: [[0, 0], 2]}}}, {$inc: {touchCount: 1}}, false, true);
@@ -41,7 +41,7 @@ assert.eq(1, t.findOne().touchCount);
 
 // 2dsphere index with $geoNear
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 var x = {
     "type": "Polygon",
     "coordinates": [[[49.999, 49.999], [50.0, 50.0], [50.001, 50.001], [49.999, 49.999]]]
@@ -62,7 +62,7 @@ var locdata = [
     {geo: {type: "Point", coordinates: [50.001, 50.001]}}
 ];
 t.save({locdata: locdata, count: 0});
-t.ensureIndex({"locdata.geo": "2dsphere"});
+t.createIndex({"locdata.geo": "2dsphere"});
 
 res = t.update({"locdata.geo": {$geoNear: {"type": "Point", "coordinates": [50.0, 50.0]}}},
                {$inc: {touchCount: 1}},
diff --git a/jstests/core/geo_validate.js b/jstests/core/geo_validate.js
index cd839ef8f97..0518740c02e 100644
--- a/jstests/core/geo_validate.js
+++ b/jstests/core/geo_validate.js
@@ -8,7 +8,7 @@
 var coll = db.geo_validate;
 coll.drop();
 
-coll.ensureIndex({geo: "2dsphere"});
+coll.createIndex({geo: "2dsphere"});
 
 //
 //
diff --git a/jstests/core/geoa.js b/jstests/core/geoa.js
index c1e0a2f796a..52a9d79db3b 100644
--- a/jstests/core/geoa.js
+++ b/jstests/core/geoa.js
@@ -10,7 +10,7 @@ t.save({_id: 1, a: {loc: [5, 5]}});
 t.save({_id: 2, a: {loc: [6, 6]}});
 t.save({_id: 3, a: {loc: [7, 7]}});
 
-t.ensureIndex({"a.loc": "2d"});
+t.createIndex({"a.loc": "2d"});
 
 cur = t.find({"a.loc": {$near: [6, 6]}});
 assert.eq(2, cur.next()._id, "A1");
diff --git a/jstests/core/geob.js b/jstests/core/geob.js
index 6a7839253ee..b1093172618 100644
--- a/jstests/core/geob.js
+++ b/jstests/core/geob.js
@@ -17,7 +17,7 @@ t.save(a);
 t.save(b);
 t.save(c);
 t.save(d);
-t.ensureIndex({p: "2d"});
+t.createIndex({p: "2d"});
 
 let res = t.aggregate({$geoNear: {near: [0, 0], distanceField: "dis"}}).toArray();
 
diff --git a/jstests/core/geoc.js b/jstests/core/geoc.js
index 4264b6f9295..2c0948582c7 100644
--- a/jstests/core/geoc.js
+++ b/jstests/core/geoc.js
@@ -15,7 +15,7 @@ for (var i = 0; i < N; i++)
 for (var i = 0; i < N; i++)
     t.insert({loc: [-100 + Math.random(), -100 + Math.random()], z: 2});
 
-t.ensureIndex({loc: '2d'});
+t.createIndex({loc: '2d'});
 
 function test(z, l) {
     assert.lt(
diff --git a/jstests/core/geod.js b/jstests/core/geod.js
index fc6c37f1da3..47b067809f8 100644
--- a/jstests/core/geod.js
+++ b/jstests/core/geod.js
@@ -2,7 +2,7 @@ var t = db.geod;
 t.drop();
 t.save({loc: [0, 0]});
 t.save({loc: [0.5, 0]});
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 // do a few geoNears with different maxDistances.  The first iteration
 // should match no points in the dataset.
 // @tags: [
diff --git a/jstests/core/geoe.js b/jstests/core/geoe.js
index 9568e13dc08..84bc34f7a74 100644
--- a/jstests/core/geoe.js
+++ b/jstests/core/geoe.js
@@ -22,7 +22,7 @@ t.insert({"_id": 12, "geo": [-122.3, 37.66]});
 t.insert({"_id": 13, "geo": [-122.2435, 37.637072]});
 t.insert({"_id": 14, "geo": [-122.289505, 37.695774]});
 
-t.ensureIndex({geo: "2d"});
+t.createIndex({geo: "2d"});
 
 c = t.find({geo: {"$within": {"$box": [[-125.078461, 36.494473], [-120.320648, 38.905199]]}}});
 assert.eq(11, c.count(), "A1");
diff --git a/jstests/core/geof.js b/jstests/core/geof.js
index ad15037db3b..31e5439b158 100644
--- a/jstests/core/geof.js
+++ b/jstests/core/geof.js
@@ -14,7 +14,7 @@ t.insert({loc: [-0.7, -0.7]});
 t.insert({loc: [-0.9, 0]});
 t.insert({loc: [-0.9, 0]});
 
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 t.find({loc: {$near: [0, 0]}}).limit(2).forEach(function(o) {
     // printjson(o);
diff --git a/jstests/core/geonear_cmd_input_validation.js b/jstests/core/geonear_cmd_input_validation.js
index 2c3116c3a6d..04f5e73fed0 100644
--- a/jstests/core/geonear_cmd_input_validation.js
+++ b/jstests/core/geonear_cmd_input_validation.js
@@ -6,7 +6,7 @@
 // ]
 var t = db.geonear_cmd_input_validation;
 t.drop();
-t.ensureIndex({loc: "2dsphere"});
+t.createIndex({loc: "2dsphere"});
 
 // The test matrix. Some combinations are not supported:
 //     2d index and GeoJSON.
diff --git a/jstests/core/getmore_invalidated_documents.js b/jstests/core/getmore_invalidated_documents.js
index 3bc5458072e..4fc66fca5c8 100644
--- a/jstests/core/getmore_invalidated_documents.js
+++ b/jstests/core/getmore_invalidated_documents.js
@@ -23,7 +23,7 @@ var y;
 
 // Case #1: Text search with deletion invalidation.
 t.drop();
-assert.commandWorked(t.ensureIndex({a: "text"}));
+assert.commandWorked(t.createIndex({a: "text"}));
 assert.commandWorked(t.insert({_id: 1, a: "bar"}));
 assert.commandWorked(t.insert({_id: 2, a: "bar"}));
 assert.commandWorked(t.insert({_id: 3, a: "bar"}));
@@ -41,7 +41,7 @@ assert(count === 0 || count === 1);
 
 // Case #2: Text search with mutation invalidation.
 t.drop();
-assert.commandWorked(t.ensureIndex({a: "text"}));
+assert.commandWorked(t.createIndex({a: "text"}));
 assert.commandWorked(t.insert({_id: 1, a: "bar"}));
 assert.commandWorked(t.insert({_id: 2, a: "bar"}));
 assert.commandWorked(t.insert({_id: 3, a: "bar"}));
@@ -60,7 +60,7 @@ assert(!cursor.hasNext() || cursor.next()["a"] === "bar");
 
 // Case #3: Merge sort with deletion invalidation.
 t.drop();
-assert.commandWorked(t.ensureIndex({a: 1, b: 1}));
+assert.commandWorked(t.createIndex({a: 1, b: 1}));
 assert.commandWorked(t.insert({a: 1, b: 1}));
 assert.commandWorked(t.insert({a: 1, b: 2}));
 assert.commandWorked(t.insert({a: 2, b: 3}));
@@ -77,7 +77,7 @@ assert(count === 1 || count === 2);
 
 // Case #4: Merge sort with mutation invalidation.
 t.drop();
-assert.commandWorked(t.ensureIndex({a: 1, b: 1}));
+assert.commandWorked(t.createIndex({a: 1, b: 1}));
 assert.commandWorked(t.insert({a: 1, b: 1}));
 assert.commandWorked(t.insert({a: 1, b: 2}));
 assert.commandWorked(t.insert({a: 2, b: 3}));
@@ -101,7 +101,7 @@ assert(!cursor.hasNext());
 
 // Case #5: 2d near with deletion invalidation.
 t.drop();
-t.ensureIndex({geo: "2d"});
+t.createIndex({geo: "2d"});
 for (x = -1; x < 1; x++) {
     for (y = -1; y < 1; y++) {
         assert.commandWorked(t.insert({geo: [x, y]}));
@@ -121,7 +121,7 @@ assert(cursor.hasNext());
 
 // Case #6: 2dsphere near with deletion invalidation.
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 for (x = -1; x < 1; x++) {
     for (y = -1; y < 1; y++) {
         assert.commandWorked(t.insert({geo: [x, y]}));
@@ -141,7 +141,7 @@ assert(cursor.hasNext());
 
 // Case #7: 2dsphere near with deletion invalidation (again).
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 for (x = 0; x < 6; x++) {
     assert.commandWorked(t.insert({geo: [x, x]}));
 }
@@ -159,7 +159,7 @@ assert.gte(cursor.itcount(), 0);
 
 // Case #8: 2d near with mutation invalidation.
 t.drop();
-t.ensureIndex({geo: "2d"});
+t.createIndex({geo: "2d"});
 for (x = -1; x < 1; x++) {
     for (y = -1; y < 1; y++) {
         assert.commandWorked(t.insert({geo: [x, y]}));
@@ -182,7 +182,7 @@ assert(nextDoc.geo[0] === 0 || nextDoc.geo[1] === 0);
 
 // Case #9: 2dsphere near with mutation invalidation.
 t.drop();
-t.ensureIndex({geo: "2dsphere"});
+t.createIndex({geo: "2dsphere"});
 for (x = -1; x < 1; x++) {
     for (y = -1; y < 1; y++) {
         assert.commandWorked(t.insert({geo: [x, y]}));
@@ -205,7 +205,7 @@ assert(nextDoc.geo[0] === 0 || nextDoc.geo[1] === 0);
 
 // Case #10: sort with deletion invalidation.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.insert({a: 1, b: 2});
 t.insert({a: 3, b: 3});
 t.insert({a: 2, b: 1});
@@ -222,7 +222,7 @@ if (cursor.hasNext()) {
 
 // Case #11: sort with mutation invalidation.
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.insert({a: 1, b: 2});
 t.insert({a: 3, b: 3});
 t.insert({a: 2, b: 1});
diff --git a/jstests/core/hint1.js b/jstests/core/hint1.js
index 6542f9752bc..d584144e641 100644
--- a/jstests/core/hint1.js
+++ b/jstests/core/hint1.js
@@ -2,7 +2,7 @@ p = db.jstests_hint1;
 p.drop();
 
 p.save({ts: new Date(1), cls: "entry", verticals: "alleyinsider", live: true});
-p.ensureIndex({ts: 1});
+p.createIndex({ts: 1});
 
 assert.eq(
     1,
diff --git a/jstests/core/idhack.js b/jstests/core/idhack.js
index a884fecd920..83a359f0f53 100644
--- a/jstests/core/idhack.js
+++ b/jstests/core/idhack.js
@@ -41,7 +41,7 @@ assert.eq(1, explain.executionStats.totalKeysExamined);
 assert(isIdhack(db, explain.queryPlanner.winningPlan));
 
 // ID hack cannot be used with hint().
-t.ensureIndex({_id: 1, a: 1});
+t.createIndex({_id: 1, a: 1});
 explain = t.find(query).hint({_id: 1, a: 1}).explain();
 assert(!isIdhack(db, explain.queryPlanner.winningPlan));
 
diff --git a/jstests/core/in.js b/jstests/core/in.js
index 852f6bcbca4..ca8cd77b189 100644
--- a/jstests/core/in.js
+++ b/jstests/core/in.js
@@ -17,7 +17,7 @@ assert.eq(1, t.find({a: {$in: [1]}}).itcount(), "A");
 assert.eq(1, t.find({a: {$in: [2]}}).itcount(), "B");
 assert.eq(2, t.find({a: {$in: [1, 2]}}).itcount(), "C");
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(1, t.find({a: {$in: [1]}}).itcount(), "D");
 assert.eq(1, t.find({a: {$in: [2]}}).itcount(), "E");
diff --git a/jstests/core/in2.js b/jstests/core/in2.js
index ddcee67ccd0..6682bbc79c1 100644
--- a/jstests/core/in2.js
+++ b/jstests/core/in2.js
@@ -17,7 +17,7 @@ function go(name, index) {
     t.save({a: 3, b: 1});
 
     if (index)
-        t.ensureIndex(index);
+        t.createIndex(index);
 
     assert.eq(7, t.find({a: {$in: [1, 2]}}).count(), name + " A");
 
diff --git a/jstests/core/in3.js b/jstests/core/in3.js
index 02680642939..bd64329ded4 100644
--- a/jstests/core/in3.js
+++ b/jstests/core/in3.js
@@ -19,5 +19,5 @@ function doTest() {
 }
 
 doTest();
-t.ensureIndex({key: 1});
+t.createIndex({key: 1});
 doTest();
diff --git a/jstests/core/in4.js b/jstests/core/in4.js
index df9eea2577b..e916ca7c82d 100644
--- a/jstests/core/in4.js
+++ b/jstests/core/in4.js
@@ -33,5 +33,5 @@ function doTest() {
 doTest();
 
 // SERVER-1943 not fixed yet
-t.ensureIndex({key: 1});
+t.createIndex({key: 1});
 doTest();
diff --git a/jstests/core/in5.js b/jstests/core/in5.js
index 2f92b057d6c..80f37e6b473 100644
--- a/jstests/core/in5.js
+++ b/jstests/core/in5.js
@@ -27,7 +27,7 @@ function go(fn) {
 
     i = {};
     i[fn] = 1;
-    t.ensureIndex(i);
+    t.createIndex(i);
 
     assert.eq(1, t.find(x).itcount(), "B1 - " + fn);
     assert.eq(1, t.find(y).itcount(), "B2 - " + fn);
@@ -39,7 +39,7 @@ function go(fn) {
 
     i = {};
     i[fn + ".a"] = 1;
-    t.ensureIndex(i);
+    t.createIndex(i);
     assert.eq(2, t.getIndexes().length, "T3");
 
     assert.eq(1, t.find(x).itcount(), "C1 - " + fn);
diff --git a/jstests/core/in6.js b/jstests/core/in6.js
index 4ee06541b81..ab8322cfe0a 100644
--- a/jstests/core/in6.js
+++ b/jstests/core/in6.js
@@ -9,5 +9,5 @@ function doTest() {
 }
 
 doTest();
-t.ensureIndex({i: 1});
+t.createIndex({i: 1});
 doTest();
diff --git a/jstests/core/in8.js b/jstests/core/in8.js
index a6bdc520926..f1b6188347c 100644
--- a/jstests/core/in8.js
+++ b/jstests/core/in8.js
@@ -8,7 +8,7 @@ function checkResults(query) {
     assert.eq(4, t.find(query).itcount());
 }
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 t.save({x: 'aa'});
 t.save({x: 'ab'});
 t.save({x: 'ac'});
diff --git a/jstests/core/inc1.js b/jstests/core/inc1.js
index 50a7892e5a4..551d15e0f63 100644
--- a/jstests/core/inc1.js
+++ b/jstests/core/inc1.js
@@ -26,7 +26,7 @@ test(5, "E");
 t.update({_id: 1}, {$inc: {x: -1}});
 test(4, "F");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 t.update({_id: 1}, {$inc: {x: 1}});
 test(5, "G");
diff --git a/jstests/core/inc2.js b/jstests/core/inc2.js
index 6ff4842e254..debdfde82cb 100644
--- a/jstests/core/inc2.js
+++ b/jstests/core/inc2.js
@@ -17,7 +17,7 @@ assert.eq("1,2,3", order(), "A");
 t.update({_id: 1}, {$inc: {x: 4}});
 assert.eq("2,3,1", order(), "B");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 assert.eq("2,3,1", order(), "C");
 
 t.update({_id: 3}, {$inc: {x: 4}});
diff --git a/jstests/core/index1.js b/jstests/core/index1.js
index 2efb9d22189..4c06bfe03fd 100644
--- a/jstests/core/index1.js
+++ b/jstests/core/index1.js
@@ -13,7 +13,7 @@ t.save(o);
 assert(t.findOne().z.a == 17);
 assert(t.findOne({z: {a: 17}}) == null);
 
-t.ensureIndex({"z.a": 1});
+t.createIndex({"z.a": 1});
 
 assert(t.findOne().z.a == 17);
 assert(t.findOne({z: {a: 17}}) == null);
diff --git a/jstests/core/index13.js b/jstests/core/index13.js
index 9979116ae51..97a3a85f773 100644
--- a/jstests/core/index13.js
+++ b/jstests/core/index13.js
@@ -40,7 +40,7 @@ index = {
     'a.b': 1,
     'a.c': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 t.save({a: [{b: 1}, {c: 1}]});
 t.save({a: [{b: 1, c: 1}]});
 assert.eq(2, t.count());
@@ -68,7 +68,7 @@ index = {
     'd.e': 1,
     'd.f': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 t.insert({a: [{b: 1}, {c: 1}], d: {e: 1, f: 1}});
 t.insert({a: [{b: 1, c: 1}], d: {e: 1, f: 1}});
 t.insert({a: {b: 1, c: 1}, d: [{e: 1, f: 1}]});
@@ -89,7 +89,7 @@ index = {
     'a.b.c': 1,
     'a.b.d': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 t.insert({a: [{b: [{c: 1, d: 1}]}]});
 t.insert({a: [{b: [{c: 1}, {d: 1}]}]});
 assert.eq(2, t.count());
@@ -104,7 +104,7 @@ index = {
     'a.b.x': 1,
     'a.b.y': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 t.save({a: {b: {x: 1, y: 1}}});
 t.save({a: [{b: {x: 1}}, {b: {y: 1}}]});
 t.save({a: [{b: [{x: 1}, {y: 1}]}]});
@@ -125,7 +125,7 @@ index = {
     'a.b.x': 1,
     'a.b.y': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 
 // With $ne.
 assertResults({a: {$ne: 4}, 'a.b': {$elemMatch: {x: 1, y: 1}}});
@@ -141,7 +141,7 @@ index = {
     'a.b.d': 1,
     'a.e.g': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 t.save({a: {b: {c: 1, d: 1}, e: {f: 1, g: 1}}});
 t.save({a: [{b: {c: 1}, e: {f: 1}}, {b: {d: 1}, e: {g: 1}}]});
 t.save({a: [{b: {c: 1}}, {e: {f: 1}}, {b: {d: 1}}, {e: {g: 1}}]});
@@ -166,7 +166,7 @@ index = {
     'a.b.d': 1,
     'a.e.d': 1
 };
-t.ensureIndex(index);
+t.createIndex(index);
 t.save({a: [{b: [{c: 1, d: 1}]}, {e: [{c: 1, d: 1}]}]});
 assert.eq(1, t.count());
 
diff --git a/jstests/core/index2.js b/jstests/core/index2.js
index 098bdc20529..2c37c48c871 100644
--- a/jstests/core/index2.js
+++ b/jstests/core/index2.js
@@ -40,7 +40,7 @@ assert(t.findOne({z: {a: 17}}).z.a == 17);
 assert(t.find({z: {a: 17}}).length() == 2);
 assert(t.find({z: {a: 18}}).length() == 1);
 
-t.ensureIndex({z: 1});
+t.createIndex({z: 1});
 
 assert(t.findOne({z: {a: 17}}).z.a == 17);
 assert(t.find({z: {a: 17}}).length() == 2);
diff --git a/jstests/core/index3.js b/jstests/core/index3.js
index 6ae7c4b82dd..cc5ad3b0796 100644
--- a/jstests/core/index3.js
+++ b/jstests/core/index3.js
@@ -7,11 +7,11 @@ t.drop();
 
 assert(t.getIndexes().length == 0);
 
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 
 t.save({name: "a"});
 
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 
 assert(t.getIndexes().length == 2);
 
diff --git a/jstests/core/index4.js b/jstests/core/index4.js
index 37ebce75a9c..179bcdd9726 100644
--- a/jstests/core/index4.js
+++ b/jstests/core/index4.js
@@ -14,10 +14,10 @@ t.save({name: "alleyinsider", instances: [{pool: "prod1"}, {pool: "dev1"}]});
 t.save({name: "clusterstock", instances: [{pool: "dev1"}]});
 
 // this should fail, not allowed -- we confirm that.
-t.ensureIndex({instances: {pool: 1}});
+t.createIndex({instances: {pool: 1}});
 assert.eq(1, t.getIndexes().length, "no indexes other than _id should be here yet");
 
-t.ensureIndex({"instances.pool": 1});
+t.createIndex({"instances.pool": 1});
 
 sleep(10);
 
diff --git a/jstests/core/index5.js b/jstests/core/index5.js
index f46654c6602..908b433c299 100644
--- a/jstests/core/index5.js
+++ b/jstests/core/index5.js
@@ -22,5 +22,5 @@ t.save({a: 2});
 
 validate();
 
-t.ensureIndex({a: -1});
+t.createIndex({a: -1});
 validate();
diff --git a/jstests/core/index6.js b/jstests/core/index6.js
index 9adef9bf366..4626e9359ea 100644
--- a/jstests/core/index6.js
+++ b/jstests/core/index6.js
@@ -4,5 +4,5 @@ r = db.ed.db.index6;
 r.drop();
 
 r.save({comments: [{name: "eliot", foo: 1}]});
-r.ensureIndex({"comments.name": 1});
+r.createIndex({"comments.name": 1});
 assert(r.findOne({"comments.name": "eliot"}));
diff --git a/jstests/core/index8.js b/jstests/core/index8.js
index 5bae0bc6de2..55ba8b805c9 100644
--- a/jstests/core/index8.js
+++ b/jstests/core/index8.js
@@ -8,9 +8,9 @@
 t = db.jstests_index8;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1}, true);
-t.ensureIndex({c: 1}, [false, "cIndex"]);
+t.createIndex({a: 1});
+t.createIndex({b: 1}, true);
+t.createIndex({c: 1}, [false, "cIndex"]);
 
 checkIndexes = function(num) {
     const indexes = t.getIndexes();
@@ -47,7 +47,7 @@ assert.eq(3, t.find().hint({b: 1}).toArray().length);
 assert.eq(3, t.find().hint({a: 1}).toArray().length);
 
 t.drop();
-t.ensureIndex({a: 1, b: -1}, true);
+t.createIndex({a: 1, b: -1}, true);
 t.save({a: 2, b: 3});
 t.save({a: 2, b: 3});
 t.save({a: 2, b: 4});
@@ -55,13 +55,13 @@ t.save({a: 1, b: 3});
 assert.eq(3, t.find().count());
 
 t.drop();
-t.ensureIndex({a: 1}, true);
+t.createIndex({a: 1}, true);
 t.save({a: [2, 3]});
 t.save({a: 2});
 assert.eq(1, t.find().count());
 
 t.drop();
-t.ensureIndex({a: 1}, true);
+t.createIndex({a: 1}, true);
 t.save({a: 2});
 t.save({a: [1, 2, 3]});
 t.save({a: [3, 2, 1]});
diff --git a/jstests/core/index_arr1.js b/jstests/core/index_arr1.js
index cc6f1683bd1..d6db3e621cd 100644
--- a/jstests/core/index_arr1.js
+++ b/jstests/core/index_arr1.js
@@ -11,11 +11,11 @@ t.insert({_id: 3, a: 5});
 
 assert.eq(3, t.find({a: 5}).itcount(), "A1");
 
-t.ensureIndex({a: 1, "b.x": 1});
+t.createIndex({a: 1, "b.x": 1});
 
 assert.eq(3, t.find({a: 5}).itcount(), "A2");  // SERVER-1082
 
 assert.eq(2, t.getIndexes().length, "B1");
 t.insert({_id: 4, a: 5, b: []});
-t.ensureIndex({a: 1, "b.a": 1, "b.c": 1});
+t.createIndex({a: 1, "b.a": 1, "b.c": 1});
 assert.eq(3, t.getIndexes().length, "B2");
diff --git a/jstests/core/index_arr2.js b/jstests/core/index_arr2.js
index cd0df2533d3..faca8be6337 100644
--- a/jstests/core/index_arr2.js
+++ b/jstests/core/index_arr2.js
@@ -24,9 +24,9 @@ function test(withIndex) {
     Z = t.find(query).count();
 
     if (withIndex) {
-        // t.ensureIndex( { 'a.b.c' : 1, 'created' : -1 } )
-        // t.ensureIndex( { created : -1 } )
-        t.ensureIndex({'a.b.c': 1}, {name: "x"});
+        // t.createIndex( { 'a.b.c' : 1, 'created' : -1 } )
+        // t.createIndex( { created : -1 } )
+        t.createIndex({'a.b.c': 1}, {name: "x"});
     }
 
     var res = t.update(query, {'$set': {"a.0.b.c": 0}}, false, true);
diff --git a/jstests/core/index_bounds_number_edge_cases.js b/jstests/core/index_bounds_number_edge_cases.js
index 0ab482028ed..3da4e53e2d0 100644
--- a/jstests/core/index_bounds_number_edge_cases.js
+++ b/jstests/core/index_bounds_number_edge_cases.js
@@ -6,7 +6,7 @@ t = db.indexboundsnumberedgecases;
 
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 t.save({a: -Infinity});
 t.save({a: -Number.MAX_VALUE});
diff --git a/jstests/core/index_check2.js b/jstests/core/index_check2.js
index 8feeb7d42a8..216ca7fb283 100644
--- a/jstests/core/index_check2.js
+++ b/jstests/core/index_check2.js
@@ -32,7 +32,7 @@ assert.eq(120, t.find(q1).itcount(), "q1 a");
 assert.eq(120, t.find(q2).itcount(), "q2 a");
 assert.eq(60, t.find(q3).itcount(), "q3 a");
 
-t.ensureIndex({tags: 1});
+t.createIndex({tags: 1});
 
 assert.eq(120, t.find(q1).itcount(), "q1 a");
 assert.eq(120, t.find(q2).itcount(), "q2 a");
diff --git a/jstests/core/index_check3.js b/jstests/core/index_check3.js
index 306b7415592..da472ecb0c9 100644
--- a/jstests/core/index_check3.js
+++ b/jstests/core/index_check3.js
@@ -14,7 +14,7 @@ t.save({a: "z"});
 assert.eq(1, t.find({a: {$lt: 2}}).itcount(), "A");
 assert.eq(1, t.find({a: {$gt: 2}}).itcount(), "B");
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(1, t.find({a: {$lt: 2}}).itcount(), "C");
 assert.eq(1, t.find({a: {$gt: 2}}).itcount(), "D");
@@ -28,7 +28,7 @@ for (var i = 0; i < 100; i++) {
     t.save(o);
 }
 
-t.ensureIndex({foo: 1});
+t.createIndex({foo: 1});
 
 var explain = t.find({foo: {$lt: 50}}).explain("executionStats");
 assert.gt(30, explain.executionStats.totalKeysExamined, "lt");
@@ -41,7 +41,7 @@ for (var i = 0; i < 10; ++i) {
     t.save({});
 }
 
-t.ensureIndex({i: 1});
+t.createIndex({i: 1});
 
 var explain = t.find({i: {$lte: 'a'}}).explain("executionStats");
 assert.gt(3, explain.executionStats.totalKeysExamined, "lte");
diff --git a/jstests/core/index_check5.js b/jstests/core/index_check5.js
index 2a3e73f9e8d..8921e014fcd 100644
--- a/jstests/core/index_check5.js
+++ b/jstests/core/index_check5.js
@@ -14,5 +14,5 @@ t.save({
 });
 
 assert.eq(2, t.find({"scores.level": 2, "scores.score": {$gt: 30}}).itcount(), "A");
-t.ensureIndex({"scores.level": 1, "scores.score": 1});
+t.createIndex({"scores.level": 1, "scores.score": 1});
 assert.eq(2, t.find({"scores.level": 2, "scores.score": {$gt: 30}}).itcount(), "B");
diff --git a/jstests/core/index_check6.js b/jstests/core/index_check6.js
index 20310d2b0dd..646d64540cf 100644
--- a/jstests/core/index_check6.js
+++ b/jstests/core/index_check6.js
@@ -12,7 +12,7 @@ function keysExamined(query, hint) {
     return explain.executionStats.totalKeysExamined;
 }
 
-t.ensureIndex({age: 1, rating: 1});
+t.createIndex({age: 1, rating: 1});
 
 for (var age = 10; age < 50; age++) {
     for (var rating = 0; rating < 10; rating++) {
@@ -98,7 +98,7 @@ for (var a = -1; a <= 1; a += 2) {
         for (var c = -1; c <= 1; c += 2) {
             t.dropIndexes();
             var spec = {a: a, b: b, c: c};
-            t.ensureIndex(spec);
+            t.createIndex(spec);
             doTest(spec, spec);
             doTest({a: -a, b: -b, c: -c}, spec);
         }
diff --git a/jstests/core/index_check7.js b/jstests/core/index_check7.js
index ae7ae7c9c71..4a4ac2a0aa1 100644
--- a/jstests/core/index_check7.js
+++ b/jstests/core/index_check7.js
@@ -9,10 +9,10 @@ t.drop();
 for (var i = 0; i < 100; i++)
     t.save({x: i});
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 assert.eq(1, t.find({x: 27}).explain(true).executionStats.totalKeysExamined, "A");
 
-t.ensureIndex({x: -1});
+t.createIndex({x: -1});
 assert.eq(1, t.find({x: 27}).explain(true).executionStats.totalKeysExamined, "B");
 
 assert.eq(40, t.find({x: {$gt: 59}}).explain(true).executionStats.totalKeysExamined, "C");
diff --git a/jstests/core/index_diag.js b/jstests/core/index_diag.js
index b336e5cc141..86f90c8d15c 100644
--- a/jstests/core/index_diag.js
+++ b/jstests/core/index_diag.js
@@ -49,7 +49,7 @@ if (FixtureHelpers.numberOfShardsForCollection(t) === 1) {
     assert.commandWorked(t.createIndex({_id: 1, x: 1}));
     assert.eq(all, t.find().hint({_id: 1, x: 1}).returnKey().toArray());
 }
-assert.commandWorked(t.ensureIndex({_id: 1, x: 1}));
+assert.commandWorked(t.createIndex({_id: 1, x: 1}));
 assert.eq(r(all), t.find().hint({_id: 1, x: 1}).sort({x: 1}).returnKey().toArray());
 
 assert.eq([{}, {}, {}], t.find().hint({$natural: 1}).returnKey().toArray());
diff --git a/jstests/core/index_dropdups_ignore.js b/jstests/core/index_dropdups_ignore.js
index aabea228c26..0cc45d65648 100644
--- a/jstests/core/index_dropdups_ignore.js
+++ b/jstests/core/index_dropdups_ignore.js
@@ -11,13 +11,13 @@ t.insert({_id: 1, a: 'dup'});
 t.insert({_id: 2, a: 'dup'});
 
 // Should fail with a dup-key error even though dropDups is true;
-var res = t.ensureIndex({a: 1}, {unique: true, dropDups: true});
+var res = t.createIndex({a: 1}, {unique: true, dropDups: true});
 assert.commandFailed(res);
 assert.eq(res.code, 11000, tojson(res));
 
 // Succeeds with the dup manually removed.
 t.remove({_id: 2});
-var res = t.ensureIndex({a: 1}, {unique: true, dropDups: true});
+var res = t.createIndex({a: 1}, {unique: true, dropDups: true});
 assert.commandWorked(res);
 
 // The spec should have been stripped of the dropDups option.
diff --git a/jstests/core/index_id_options.js b/jstests/core/index_id_options.js
index 91bdce8090f..475a1a6fe95 100644
--- a/jstests/core/index_id_options.js
+++ b/jstests/core/index_id_options.js
@@ -21,12 +21,12 @@ var coll = db.getSiblingDB("local").index_id_options;
 // _id indexes must have key pattern {_id: 1}.
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false}));
-assert.commandFailed(coll.ensureIndex({_id: -1}, {name: "_id_"}));
+assert.commandFailed(coll.createIndex({_id: -1}, {name: "_id_"}));
 
 // The name of an _id index gets corrected to "_id_".
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false}));
-assert.commandWorked(coll.ensureIndex({_id: 1}, {name: "bad"}));
+assert.commandWorked(coll.createIndex({_id: 1}, {name: "bad"}));
 var spec = GetIndexHelpers.findByKeyPattern(coll.getIndexes(), {_id: 1});
 assert.neq(null, spec, "_id index spec not found");
 assert.eq("_id_", spec.name, tojson(spec));
@@ -34,35 +34,35 @@ assert.eq("_id_", spec.name, tojson(spec));
 // _id indexes cannot have any options other than "key", "name", "ns", "v", and "collation."
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", unique: true}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", sparse: false}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", partialFilterExpression: {a: 1}}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", expireAfterSeconds: 3600}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", background: false}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", unknown: true}));
-assert.commandWorked(coll.ensureIndex(
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", unique: true}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", sparse: false}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", partialFilterExpression: {a: 1}}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", expireAfterSeconds: 3600}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", background: false}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", unknown: true}));
+assert.commandWorked(coll.createIndex(
     {_id: 1}, {name: "_id_", ns: coll.getFullName(), v: 2, collation: {locale: "simple"}}));
 
 // _id indexes must have the collection default collation.
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({_id: 1}, {name: "_id_", collation: {locale: "simple"}}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", collation: {locale: "en_US"}}));
+assert.commandWorked(coll.createIndex({_id: 1}, {name: "_id_", collation: {locale: "simple"}}));
 
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false}));
-assert.commandWorked(coll.ensureIndex({_id: 1}, {name: "_id_"}));
+assert.commandWorked(coll.createIndex({_id: 1}, {name: "_id_"}));
 
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false, collation: {locale: "en_US"}}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", collation: {locale: "simple"}}));
-assert.commandFailed(coll.ensureIndex({_id: 1}, {name: "_id_", collation: {locale: "fr_CA"}}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", collation: {locale: "simple"}}));
+assert.commandFailed(coll.createIndex({_id: 1}, {name: "_id_", collation: {locale: "fr_CA"}}));
 assert.commandWorked(
-    coll.ensureIndex({_id: 1}, {name: "_id_", collation: {locale: "en_US", strength: 3}}));
+    coll.createIndex({_id: 1}, {name: "_id_", collation: {locale: "en_US", strength: 3}}));
 
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false, collation: {locale: "en_US"}}));
-assert.commandWorked(coll.ensureIndex({_id: 1}, {name: "_id_"}));
+assert.commandWorked(coll.createIndex({_id: 1}, {name: "_id_"}));
 spec = GetIndexHelpers.findByName(coll.getIndexes(), "_id_");
 assert.neq(null, spec, "_id index spec not found");
 assert.eq("en_US", spec.collation.locale, tojson(spec));
@@ -70,6 +70,6 @@ assert.eq("en_US", spec.collation.locale, tojson(spec));
 // Non-_id indexes cannot have the name "_id_".
 coll.drop();
 assert.commandWorked(coll.runCommand("create", {autoIndexId: false}));
-assert.commandFailed(coll.ensureIndex({_id: "hashed"}, {name: "_id_"}));
-assert.commandFailed(coll.ensureIndex({a: 1}, {name: "_id_"}));
+assert.commandFailed(coll.createIndex({_id: "hashed"}, {name: "_id_"}));
+assert.commandFailed(coll.createIndex({a: 1}, {name: "_id_"}));
 })();
diff --git a/jstests/core/index_many.js b/jstests/core/index_many.js
index f95d4ac50de..cdd559c9be5 100644
--- a/jstests/core/index_many.js
+++ b/jstests/core/index_many.js
@@ -22,7 +22,7 @@ function f() {
             patt = {x: 1};
         if (x == 64)
             patt = {y: 1};
-        lastErr = t.ensureIndex(patt);
+        lastErr = t.createIndex(patt);
         x++;
     }
 
diff --git a/jstests/core/index_many2.js b/jstests/core/index_many2.js
index f6f6b0cb392..70fada7396e 100644
--- a/jstests/core/index_many2.js
+++ b/jstests/core/index_many2.js
@@ -16,7 +16,7 @@ function make(n) {
 }
 
 for (i = 1; i < 1000; i++) {
-    t.ensureIndex(make(i));
+    t.createIndex(make(i));
 }
 
 assert.eq(64, t.getIndexKeys().length, "A2");
@@ -26,7 +26,7 @@ num = t.getIndexKeys().length;
 t.dropIndex(make(num - 1));
 assert.eq(num - 1, t.getIndexKeys().length, "B0");
 
-t.ensureIndex({z: 1});
+t.createIndex({z: 1});
 assert.eq(num, t.getIndexKeys().length, "B1");
 
 t.dropIndexes("*");
diff --git a/jstests/core/index_partial_validate.js b/jstests/core/index_partial_validate.js
index 2319aac2954..5011b4b8bc2 100644
--- a/jstests/core/index_partial_validate.js
+++ b/jstests/core/index_partial_validate.js
@@ -6,10 +6,10 @@
 var t = db.index_partial_validate;
 t.drop();
 
-var res = t.ensureIndex({a: 1}, {partialFilterExpression: {a: {$lte: 1}}});
+var res = t.createIndex({a: 1}, {partialFilterExpression: {a: {$lte: 1}}});
 assert.commandWorked(res);
 
-res = t.ensureIndex({b: 1});
+res = t.createIndex({b: 1});
 assert.commandWorked(res);
 
 res = t.insert({non_indexed_field: 'x'});
diff --git a/jstests/core/index_partial_write_ops.js b/jstests/core/index_partial_write_ops.js
index df80ac33b42..6adcb8933fd 100644
--- a/jstests/core/index_partial_write_ops.js
+++ b/jstests/core/index_partial_write_ops.js
@@ -21,7 +21,7 @@ var getNumKeys = function(idxName) {
 coll.drop();
 
 // Create partial index.
-assert.commandWorked(coll.ensureIndex({x: 1}, {unique: true, partialFilterExpression: {a: 1}}));
+assert.commandWorked(coll.createIndex({x: 1}, {unique: true, partialFilterExpression: {a: 1}}));
 
 assert.commandWorked(coll.insert({_id: 1, x: 5, a: 2, b: 1}));  // Not in index.
 assert.commandWorked(coll.insert({_id: 2, x: 6, a: 1, b: 1}));  // In index.
diff --git a/jstests/core/index_sparse1.js b/jstests/core/index_sparse1.js
index a7c1e8605ef..58bc5baa9b8 100644
--- a/jstests/core/index_sparse1.js
+++ b/jstests/core/index_sparse1.js
@@ -14,13 +14,13 @@ t.insert({_id: 5});
 assert.eq(5, t.count(), "A1");
 assert.eq(5, t.find().sort({x: 1}).itcount(), "A2");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 assert.eq(2, t.getIndexes().length, "B1");
 assert.eq(5, t.find().sort({x: 1}).itcount(), "B2");
 t.dropIndex({x: 1});
 assert.eq(1, t.getIndexes().length, "B3");
 
-t.ensureIndex({x: 1}, {sparse: 1});
+t.createIndex({x: 1}, {sparse: 1});
 assert.eq(2, t.getIndexes().length, "C1");
 assert.eq(5, t.find().sort({x: 1}).itcount(), "C2");
 t.dropIndex({x: 1});
@@ -31,14 +31,14 @@ assert.eq(1, t.getIndexes().length, "C3");
 t.remove({_id: 2});
 
 // test that we can't create a unique index without sparse
-assert.commandFailed(t.ensureIndex({x: 1}, {unique: 1}));
+assert.commandFailed(t.createIndex({x: 1}, {unique: 1}));
 assert.eq(1, t.getIndexes().length, "D2");
 
-t.ensureIndex({x: 1}, {unique: 1, sparse: 1});
+t.createIndex({x: 1}, {unique: 1, sparse: 1});
 assert.eq(2, t.getIndexes().length, "E1");
 t.dropIndex({x: 1});
 assert.eq(1, t.getIndexes().length, "E3");
 
 t.insert({_id: 2, x: 2});
-t.ensureIndex({x: 1}, {unique: 1, sparse: 1});
+t.createIndex({x: 1}, {unique: 1, sparse: 1});
 assert.eq(1, t.getIndexes().length, "F1");
diff --git a/jstests/core/index_sparse2.js b/jstests/core/index_sparse2.js
index 148ad70b203..324b46d8216 100644
--- a/jstests/core/index_sparse2.js
+++ b/jstests/core/index_sparse2.js
@@ -9,14 +9,14 @@ t.insert({_id: 1, x: 1, y: 1});
 t.insert({_id: 2, x: 2});
 t.insert({_id: 3});
 
-t.ensureIndex({x: 1, y: 1});
+t.createIndex({x: 1, y: 1});
 assert.eq(2, t.getIndexes().length, "A1");
 assert.eq(3, t.find().sort({x: 1, y: 1}).count(), "A2 count()");
 assert.eq(3, t.find().sort({x: 1, y: 1}).itcount(), "A2 itcount()");
 t.dropIndex({x: 1, y: 1});
 assert.eq(1, t.getIndexes().length, "A3");
 
-t.ensureIndex({x: 1, y: 1}, {sparse: 1});
+t.createIndex({x: 1, y: 1}, {sparse: 1});
 assert.eq(2, t.getIndexes().length, "B1");
 assert.eq(3, t.find().sort({x: 1, y: 1}).count(), "B2 count()");
 assert.eq(3, t.find().sort({x: 1, y: 1}).itcount(), "B2 itcount()");
diff --git a/jstests/core/index_type_change.js b/jstests/core/index_type_change.js
index 4ecb5081347..d23984a132d 100644
--- a/jstests/core/index_type_change.js
+++ b/jstests/core/index_type_change.js
@@ -18,7 +18,7 @@ load("jstests/libs/analyze_plan.js");  // For 'isIndexOnly'.
 
 var coll = db.index_type_change;
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
 
 assert.commandWorked(coll.insert({a: 2}));
 assert.eq(1, coll.find({a: {$type: "double"}}).itcount());
diff --git a/jstests/core/indexa.js b/jstests/core/indexa.js
index 90e74adc4f4..01fde035621 100644
--- a/jstests/core/indexa.js
+++ b/jstests/core/indexa.js
@@ -8,7 +8,7 @@
 t = db.indexa;
 t.drop();
 
-t.ensureIndex({x: 1}, true);
+t.createIndex({x: 1}, true);
 
 t.insert({'x': 'A'});
 t.insert({'x': 'B'});
diff --git a/jstests/core/indexapi.js b/jstests/core/indexapi.js
index 14cf634e556..29d39ea721b 100644
--- a/jstests/core/indexapi.js
+++ b/jstests/core/indexapi.js
@@ -31,14 +31,14 @@ c.dropDups = true;
 assert.eq(c, t._indexSpec({x: 1}, [true, true]), "G");
 assert.eq(c, t._indexSpec({x: 1}, {unique: true, dropDups: true}), "F");
 
-t.ensureIndex({x: 1}, {unique: true});
+t.createIndex({x: 1}, {unique: true});
 idx = t.getIndexes();
 assert.eq(2, idx.length, "M1");
 assert.eq(key, idx[1].key, "M2");
 assert(idx[1].unique, "M3");
 
 t.drop();
-t.ensureIndex({x: 1}, {unique: 1});
+t.createIndex({x: 1}, {unique: 1});
 idx = t.getIndexes();
 assert.eq(2, idx.length, "M1");
 assert.eq(key, idx[1].key, "M2");
diff --git a/jstests/core/indexb.js b/jstests/core/indexb.js
index 6890dda3cbc..59546f7fae2 100644
--- a/jstests/core/indexb.js
+++ b/jstests/core/indexb.js
@@ -10,7 +10,7 @@
 
 t = db.indexb;
 t.drop();
-t.ensureIndex({a: 1}, true);
+t.createIndex({a: 1}, true);
 
 t.insert({a: 1});
 
diff --git a/jstests/core/indexc.js b/jstests/core/indexc.js
index 3bc4c9eaca8..bf5735380fa 100644
--- a/jstests/core/indexc.js
+++ b/jstests/core/indexc.js
@@ -13,8 +13,8 @@ for (var i = 1; i < 100; i++) {
 assert.eq(50, t.find({ts: {$lt: mid}}).itcount(), "A");
 assert.eq(50, t.find({ts: {$lt: mid}}).sort({ts: 1}).itcount(), "B");
 
-t.ensureIndex({ts: 1, cats: 1});
-t.ensureIndex({cats: 1});
+t.createIndex({ts: 1, cats: 1});
+t.createIndex({cats: 1});
 
 // multi-key bug was firing here (related to getsetdup()):
 assert.eq(50, t.find({ts: {$lt: mid}}).itcount(), "C");
diff --git a/jstests/core/indexe.js b/jstests/core/indexe.js
index 6961229c682..a307882adc3 100644
--- a/jstests/core/indexe.js
+++ b/jstests/core/indexe.js
@@ -13,7 +13,7 @@ assert.eq(num, t.find().count(), "A1");
 assert.eq(num, t.find({a: "b"}).count(), "B1");
 assert.eq(num, t.find({a: "b"}).itcount(), "C1");
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(num, t.find().count(), "A2");
 assert.eq(num, t.find().sort({a: 1}).count(), "A2a");
diff --git a/jstests/core/indexf.js b/jstests/core/indexf.js
index cbe1b968b5e..4dc8fb0b060 100644
--- a/jstests/core/indexf.js
+++ b/jstests/core/indexf.js
@@ -7,7 +7,7 @@
 t = db.indexf;
 t.drop();
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 t.save({x: 2});
 t.save({y: 3});
diff --git a/jstests/core/indexg.js b/jstests/core/indexg.js
index 3cafede4cff..486f4be0ebe 100644
--- a/jstests/core/indexg.js
+++ b/jstests/core/indexg.js
@@ -9,5 +9,5 @@ doit = function() {
     assert.eq(1, f.count({list: {$in: [1], $not: {$in: [3]}}}));
 };
 doit();
-f.ensureIndex({list: 1});
+f.createIndex({list: 1});
 doit();
 \ No newline at end of file
diff --git a/jstests/core/indexj.js b/jstests/core/indexj.js
index 76bf8cb17e9..64cf9844d7f 100644
--- a/jstests/core/indexj.js
+++ b/jstests/core/indexj.js
@@ -20,12 +20,12 @@ function keysExamined(query, hint, sort) {
     return explain.executionStats.totalKeysExamined;
 }
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: 5});
 assert.eq(0, keysExamined({a: {$gt: 4, $lt: 5}}), "A");
 
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: 4});
 assert.eq(0, keysExamined({a: {$gt: 4, $lt: 5}}), "B");
 
@@ -39,7 +39,7 @@ t.save({a: 5});
 assert.eq(0, keysExamined({a: {$gt: 4, $lt: 5}}), "D");
 
 t.drop();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 t.save({a: 1, b: 1});
 t.save({a: 1, b: 2});
 t.save({a: 2, b: 1});
diff --git a/jstests/core/indexl.js b/jstests/core/indexl.js
index c83638607d4..cde169eda71 100644
--- a/jstests/core/indexl.js
+++ b/jstests/core/indexl.js
@@ -23,5 +23,5 @@ function test(t) {
 t.drop();
 test(t);
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test(t);
 \ No newline at end of file
diff --git a/jstests/core/indexm.js b/jstests/core/indexm.js
index 820bedd7baa..7613b125357 100644
--- a/jstests/core/indexm.js
+++ b/jstests/core/indexm.js
@@ -13,12 +13,12 @@ function test() {
 test();
 
 // Now create an index.
-t.ensureIndex({"a": 1});
+t.createIndex({"a": 1});
 test();
 
 // Now create a different index.
 t.dropIndexes();
-t.ensureIndex({"a.x": 1});
+t.createIndex({"a.x": 1});
 test();
 
 // Drop the indexes.
diff --git a/jstests/core/indexn.js b/jstests/core/indexn.js
index 014ba050cbc..02547280ad9 100644
--- a/jstests/core/indexn.js
+++ b/jstests/core/indexn.js
@@ -9,8 +9,8 @@ t.drop();
 
 t.save({a: 1, b: [1, 2]});
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 // {a:1} is a single key index, so no matches are possible for this query
 assert.eq(0, t.count({a: {$gt: 5, $lt: 0}}));
diff --git a/jstests/core/indexp.js b/jstests/core/indexp.js
index 71e9f8eadb9..8199e0f132c 100644
--- a/jstests/core/indexp.js
+++ b/jstests/core/indexp.js
@@ -6,18 +6,18 @@
 var coll = db.jstests_indexp;
 
 // Empty field checks.
-assert.commandFailed(coll.ensureIndex({'a..b': 1}));
-assert.commandFailed(coll.ensureIndex({'.a': 1}));
-assert.commandFailed(coll.ensureIndex({'a.': 1}));
-assert.commandFailed(coll.ensureIndex({'.': 1}));
-assert.commandFailed(coll.ensureIndex({'': 1}));
-assert.commandWorked(coll.ensureIndex({'a.b': 1}));
+assert.commandFailed(coll.createIndex({'a..b': 1}));
+assert.commandFailed(coll.createIndex({'.a': 1}));
+assert.commandFailed(coll.createIndex({'a.': 1}));
+assert.commandFailed(coll.createIndex({'.': 1}));
+assert.commandFailed(coll.createIndex({'': 1}));
+assert.commandWorked(coll.createIndex({'a.b': 1}));
 
 // '$'-prefixed field checks.
-assert.commandFailed(coll.ensureIndex({'$a': 1}));
-assert.commandFailed(coll.ensureIndex({'a.$b': 1}));
-assert.commandFailed(coll.ensureIndex({'$db': 1}));
-assert.commandWorked(coll.ensureIndex({'a$ap': 1}));   // $ in middle is ok
-assert.commandWorked(coll.ensureIndex({'a.$id': 1}));  // $id/$db/$ref are execptions
+assert.commandFailed(coll.createIndex({'$a': 1}));
+assert.commandFailed(coll.createIndex({'a.$b': 1}));
+assert.commandFailed(coll.createIndex({'$db': 1}));
+assert.commandWorked(coll.createIndex({'a$ap': 1}));   // $ in middle is ok
+assert.commandWorked(coll.createIndex({'a.$id': 1}));  // $id/$db/$ref are execptions
 
 coll.dropIndexes();
diff --git a/jstests/core/indexr.js b/jstests/core/indexr.js
index 15cd56e9681..de3afe8cdc1 100644
--- a/jstests/core/indexr.js
+++ b/jstests/core/indexr.js
@@ -15,8 +15,8 @@ assert.eq(1, t.count({a: {b: 3, c: 6}, 'a.c': {$lt: 4}}));
 
 // Check with single key indexes.
 t.remove({});
-t.ensureIndex({'a.b': 1, 'a.c': 1});
-t.ensureIndex({a: 1, 'a.c': 1});
+t.createIndex({'a.b': 1, 'a.c': 1});
+t.createIndex({a: 1, 'a.c': 1});
 assert.eq(0, t.count({'a.b': {$gt: 2}, 'a.c': {$lt: 4}}));
 assert.eq(0, t.count({a: {b: 3, c: 6}, 'a.c': {$lt: 4}}));
 
diff --git a/jstests/core/indexs.js b/jstests/core/indexs.js
index 2fc9724a590..6ee625071e2 100644
--- a/jstests/core/indexs.js
+++ b/jstests/core/indexs.js
@@ -4,16 +4,16 @@
 t = db.jstests_indexs;
 
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: [{b: 3}]});
 assert.eq(1, t.count({a: {b: 3}}));
 
 t.drop();
-t.ensureIndex({a: 1, 'a.b': 1});
+t.createIndex({a: 1, 'a.b': 1});
 t.save({a: {b: 3}});
 assert.eq(1, t.count({a: {b: 3}}));
 
 t.drop();
-t.ensureIndex({a: 1, 'a.b': 1});
+t.createIndex({a: 1, 'a.b': 1});
 t.save({a: [{b: 3}]});
 assert.eq(1, t.count({a: {b: 3}}));
diff --git a/jstests/core/indext.js b/jstests/core/indext.js
index 163a3e4a8a3..1ac92d6be5d 100644
--- a/jstests/core/indext.js
+++ b/jstests/core/indext.js
@@ -3,12 +3,12 @@
 t = db.jstests_indext;
 t.drop();
 
-t.ensureIndex({'a.b': 1}, {sparse: true});
+t.createIndex({'a.b': 1}, {sparse: true});
 t.save({a: []});
 t.save({a: 1});
 assert.eq(0, t.find().hint({'a.b': 1}).itcount());
 
-t.ensureIndex({'a.b': 1, 'a.c': 1}, {sparse: true});
+t.createIndex({'a.b': 1, 'a.c': 1}, {sparse: true});
 t.save({a: []});
 t.save({a: 1});
 assert.eq(0, t.find().hint({'a.b': 1, 'a.c': 1}).itcount());
diff --git a/jstests/core/indexu.js b/jstests/core/indexu.js
index 22af42d5d6a..973fc0e4985 100644
--- a/jstests/core/indexu.js
+++ b/jstests/core/indexu.js
@@ -15,56 +15,56 @@ var noDupDoc = {a: [{'1': 1}]};
 
 // Test that we can't index dupDoc.
 assert.commandWorked(t.save(dupDoc));
-assert.commandFailedWithCode(t.ensureIndex({'a.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0': 1}), 16746);
 
 // Test that we can fail gracefully when dupDoc has a large array padded with nulls.
 // Index is based on max padding constant in mongo/db/update/path_support.h
 assert.commandWorked(t.update({_id: 0}, {$set: {'a.1500001': 1}}));
-assert.commandFailedWithCode(t.ensureIndex({'a.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0': 1}), 16746);
 
 t.remove({});
-assert.commandWorked(t.ensureIndex({'a.0': 1}));
+assert.commandWorked(t.createIndex({'a.0': 1}));
 assert.writeError(t.save(dupDoc));
 
 // Test that we can't index dupDoc2.
 t.drop();
 assert.commandWorked(t.save(dupDoc2));
-assert.commandFailedWithCode(t.ensureIndex({'a.1': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.1': 1}), 16746);
 
 t.remove({});
-assert.commandWorked(t.ensureIndex({'a.1': 1}));
+assert.commandWorked(t.createIndex({'a.1': 1}));
 assert.writeError(t.save(dupDoc2));
 
 // Test that we can index dupDoc with a different index.
 t.drop();
-t.ensureIndex({'a.b': 1});
+t.createIndex({'a.b': 1});
 assert.commandWorked(t.save(dupDoc));
 
 // Test number field starting with hyphen.
 t.drop();
-t.ensureIndex({'a.-1': 1});
+t.createIndex({'a.-1': 1});
 assert.commandWorked(t.save({a: [{'-1': 1}]}));
 
 // Test number field starting with zero.
 t.drop();
-t.ensureIndex({'a.00': 1});
+t.createIndex({'a.00': 1});
 assert.commandWorked(t.save({a: [{'00': 1}]}));
 
 // Test multiple array indexes
 t.drop();
-t.ensureIndex({'a.0': 1, 'a.1': 1});
+t.createIndex({'a.0': 1, 'a.1': 1});
 assert.commandWorked(t.save({a: [{'1': 1}]}));
 assert.writeError(t.save({a: [{'1': 1}, 4]}));
 
 // Test that we can index noDupDoc.
 t.drop();
 t.save(noDupDoc);
-assert.commandWorked(t.ensureIndex({'a.0': 1}));
-assert.commandWorked(t.ensureIndex({'a.1': 1}));
+assert.commandWorked(t.createIndex({'a.0': 1}));
+assert.commandWorked(t.createIndex({'a.1': 1}));
 
 t.drop();
-t.ensureIndex({'a.0': 1});
-t.ensureIndex({'a.1': 1});
+t.createIndex({'a.0': 1});
+t.createIndex({'a.1': 1});
 assert.commandWorked(t.save(noDupDoc));
 
 // Test that we can query noDupDoc.
@@ -76,7 +76,7 @@ assert.eq(1, t.find({'a.0': {'1': 1}}).hint({$natural: 1}).itcount());
 // Check multiple nested array fields.
 t.drop();
 t.save({a: [[1]]});
-assert.commandWorked(t.ensureIndex({'a.0.0': 1}));
+assert.commandWorked(t.createIndex({'a.0.0': 1}));
 assert.eq(1, t.find({'a.0.0': 1}).hint({$natural: 1}).itcount());
 assert.eq(1, t.find({'a.0.0': 1}).hint({'a.0.0': 1}).itcount());
 
@@ -84,36 +84,36 @@ assert.eq(1, t.find({'a.0.0': 1}).hint({'a.0.0': 1}).itcount());
 // field.
 t.drop();
 t.save({a: [[1], {'0': 1}]});
-assert.commandFailed(t.ensureIndex({'a.0.0': 1}));
+assert.commandFailed(t.createIndex({'a.0.0': 1}));
 
 // Check where there is a duplicate for a fully addressed field.
 t.drop();
 assert.commandWorked(t.save({a: [[1], {'0': [1]}]}));
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.0': 1}), 16746);
 
 // Two ways of addressing parse to an array.
 t.drop();
 t.save({a: [{'0': 1}]});
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.0': 1}), 16746);
 
 // Test several key depths - with same arrays being found.
 t.drop();
 t.save({a: [{'0': [{'0': 1}]}]});
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0.0.0.0.0': 1}), 16746);
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0.0.0.0': 1}), 16746);
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0.0.0': 1}), 16746);
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0.0': 1}), 16746);
-assert.commandFailedWithCode(t.ensureIndex({'a.0.0': 1}), 16746);
-assert.commandFailedWithCode(t.ensureIndex({'a.0': 1}), 16746);
-assert.commandWorked(t.ensureIndex({'a': 1}));
+assert.commandFailedWithCode(t.createIndex({'a.0.0.0.0.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.0.0.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.0.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.0': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0': 1}), 16746);
+assert.commandWorked(t.createIndex({'a': 1}));
 
 // Two prefixes extract docs, but one terminates extraction before array.
 t.drop();
 t.save({a: [{'0': {'c': []}}]});
-assert.commandFailedWithCode(t.ensureIndex({'a.0.c': 1}), 16746);
+assert.commandFailedWithCode(t.createIndex({'a.0.c': 1}), 16746);
 
 t.drop();
 t.save({a: [[{'b': 1}]]});
 assert.eq(1, t.find({'a.0.b': 1}).itcount());
-t.ensureIndex({'a.0.b': 1});
+t.createIndex({'a.0.b': 1});
 assert.eq(1, t.find({'a.0.b': 1}).itcount());
diff --git a/jstests/core/insert_illegal_doc.js b/jstests/core/insert_illegal_doc.js
index 64ecb0ae7ad..f6344f1c62b 100644
--- a/jstests/core/insert_illegal_doc.js
+++ b/jstests/core/insert_illegal_doc.js
@@ -2,7 +2,7 @@
 // "parallel indexing of arrays" test
 var coll = db.insert_illegal_doc;
 coll.drop();
-coll.ensureIndex({a: 1, b: 1});
+coll.createIndex({a: 1, b: 1});
 
 var res;
 // test upsert
diff --git a/jstests/core/js3.js b/jstests/core/js3.js
index 89847210714..8698195d6c4 100644
--- a/jstests/core/js3.js
+++ b/jstests/core/js3.js
@@ -18,8 +18,8 @@ for (z = 0; z < 2; z++) {
     t.drop();
 
     if (z > 0) {
-        t.ensureIndex({_id: 1});
-        t.ensureIndex({i: 1});
+        t.createIndex({_id: 1});
+        t.createIndex({i: 1});
     }
 
     for (i = 0; i < 1000; i++)
@@ -51,8 +51,8 @@ for (z = 0; z < 2; z++) {
     debug(ok);
     assert(ok);
 
-    t.ensureIndex({z: 1});
-    t.ensureIndex({q: 1});
+    t.createIndex({z: 1});
+    t.createIndex({q: 1});
 
     debug("before indexed find");
 
diff --git a/jstests/core/list_indexes.js b/jstests/core/list_indexes.js
index 040d30e6290..a81a1adf68a 100644
--- a/jstests/core/list_indexes.js
+++ b/jstests/core/list_indexes.js
@@ -59,7 +59,7 @@ assert.eq(["_id_"], cursorGetIndexNames(getListIndexesCursor(coll)));
 
 coll.drop();
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
-assert.commandWorked(coll.ensureIndex({a: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({a: 1}, {unique: true}));
 specs = cursorGetIndexSpecs(getListIndexesCursor(coll));
 assert.eq(2, specs.length);
 assert.eq("_id_", specs[0].name);
@@ -84,7 +84,7 @@ assert.commandFailed(coll.getDB().runCommand({listIndexes: []}));
 
 coll.drop();
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
-assert.commandWorked(coll.ensureIndex({a: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({a: 1}, {unique: true}));
 
 cursor = getListIndexesCursor(coll, {cursor: {batchSize: 2}});
 assert.eq(2, cursor.objsLeftInBatch());
@@ -124,9 +124,9 @@ assert.eq(["_id_", "a_1"], cursorGetIndexNames(cursor));
 
 coll.drop();
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
-assert.commandWorked(coll.ensureIndex({a: 1}, {unique: true}));
-assert.commandWorked(coll.ensureIndex({b: 1}, {unique: true}));
-assert.commandWorked(coll.ensureIndex({c: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({a: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({b: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({c: 1}, {unique: true}));
 
 cursor = getListIndexesCursor(coll, {cursor: {batchSize: 0}}, 2);
 assert.eq(0, cursor.objsLeftInBatch());
@@ -167,9 +167,9 @@ if (!FixtureHelpers.isMongos(db)) {
 
 coll.drop();
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
-assert.commandWorked(coll.ensureIndex({a: 1}, {unique: true}));
-assert.commandWorked(coll.ensureIndex({b: 1}, {unique: true}));
-assert.commandWorked(coll.ensureIndex({c: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({a: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({b: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({c: 1}, {unique: true}));
 
 res = coll.runCommand("listIndexes", {cursor: {batchSize: 0}});
 cursor = new DBCommandCursor(coll.getDB(), res, 2);
diff --git a/jstests/core/list_indexes_invalid.js b/jstests/core/list_indexes_invalid.js
index 43d64a594c2..7b73a4278ce 100644
--- a/jstests/core/list_indexes_invalid.js
+++ b/jstests/core/list_indexes_invalid.js
@@ -8,7 +8,7 @@ var coll = db.list_indexes_invalid;
 coll.drop();
 
 assert.commandWorked(coll.getDB().createCollection(coll.getName()));
-assert.commandWorked(coll.ensureIndex({a: 1}, {unique: true}));
+assert.commandWorked(coll.createIndex({a: 1}, {unique: true}));
 
 assert.throws(function() {
     getListIndexesCursor(coll, {cursor: 0});
diff --git a/jstests/core/minmax.js b/jstests/core/minmax.js
index 14f4ed0ec2c..b4f181689a2 100644
--- a/jstests/core/minmax.js
+++ b/jstests/core/minmax.js
@@ -16,7 +16,7 @@ function addData() {
     assert.commandWorked(coll.save({a: 2, b: 2}));
 }
 
-assert.commandWorked(coll.ensureIndex({a: 1, b: 1}));
+assert.commandWorked(coll.createIndex({a: 1, b: 1}));
 addData();
 
 assert.eq(1, coll.find().hint({a: 1, b: 1}).min({a: 1, b: 2}).max({a: 2, b: 1}).toArray().length);
@@ -31,7 +31,7 @@ assert.eq(3,
           coll.find().hint({a: 1, b: 1}).max({a: 2, b: 1.5}).hint({a: 1, b: 1}).toArray().length);
 
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1, b: -1}));
+assert.commandWorked(coll.createIndex({a: 1, b: -1}));
 addData();
 assert.eq(4, coll.find().hint({a: 1, b: -1}).min({a: 1, b: 2}).toArray().length);
 assert.eq(4, coll.find().hint({a: 1, b: -1}).max({a: 2, b: 0.5}).toArray().length);
@@ -78,7 +78,7 @@ error = assert.throws(function() {
 assert.eq(error.code, ErrorCodes.NoQueryExecutionPlans);
 
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
 for (let i = 0; i < 10; ++i) {
     assert.commandWorked(coll.save({_id: i, a: i}));
 }
@@ -103,7 +103,7 @@ assert.eq(error.code, 51175);
 
 coll.drop();
 addData();
-assert.commandWorked(coll.ensureIndex({a: 1, b: 1}));
+assert.commandWorked(coll.createIndex({a: 1, b: 1}));
 
 error = assert.throws(function() {
     coll.find().min({a: 1, b: 2}).max({a: 1, b: 2}).hint({a: 1, b: 1}).toArray();
@@ -112,7 +112,7 @@ assert.eq(error.code, 51175);
 
 // Test ascending index.
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
 assert.commandWorked(coll.insert({a: 3}));
 assert.commandWorked(coll.insert({a: 4}));
 assert.commandWorked(coll.insert({a: 5}));
@@ -134,7 +134,7 @@ assert(!cursor.hasNext());
 
 // Test descending index.
 assert.commandWorked(coll.dropIndexes());
-assert.commandWorked(coll.ensureIndex({a: -1}));
+assert.commandWorked(coll.createIndex({a: -1}));
 
 cursor = coll.find().hint({a: -1}).min({a: 4});
 if (FixtureHelpers.numberOfShardsForCollection(coll) === 1) {
diff --git a/jstests/core/mr_multikey_deduping.js b/jstests/core/mr_multikey_deduping.js
index 604635a67fc..e3f729ef16f 100644
--- a/jstests/core/mr_multikey_deduping.js
+++ b/jstests/core/mr_multikey_deduping.js
@@ -39,7 +39,7 @@ outColl.drop();
     assert(outColl.drop());
 
     // Now test that we get the same results when there's an index present.
-    assert.commandWorked(coll.ensureIndex({arr: 1}));
+    assert.commandWorked(coll.createIndex({arr: 1}));
     res = assert.commandWorked(coll.mapReduce(
         mapFn, reduceFn, {out: {merge: outColl.getName()}, query: {arr: {$gte: 0}}}));
     assert(outColl.drop());
@@ -93,7 +93,7 @@ outColl.drop();
         resultsEq([{_id: "cat", value: 1}, {_id: "dog", value: 1}], resultsNoIndexEqualityOnName));
     assert(resultsEq(resultsNoIndexNoQuery, resultsNoIndexRangeOnName));
 
-    assert.commandWorked(coll.ensureIndex({name: 1, tags: 1}));
+    assert.commandWorked(coll.createIndex({name: 1, tags: 1}));
 
     const resultsIndexedNoQuery =
         assert
diff --git a/jstests/core/mr_sort.js b/jstests/core/mr_sort.js
index df98e6a6d3d..c1ce7d3861b 100644
--- a/jstests/core/mr_sort.js
+++ b/jstests/core/mr_sort.js
@@ -12,7 +12,7 @@
 t = db.mr_sort;
 t.drop();
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 t.insert({x: 1});
 t.insert({x: 10});
diff --git a/jstests/core/multi.js b/jstests/core/multi.js
index c7853b18f25..ac961ed7a9c 100644
--- a/jstests/core/multi.js
+++ b/jstests/core/multi.js
@@ -1,7 +1,7 @@
 t = db.jstests_multi;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: [1, 2]});
 assert.eq(1, t.find({a: {$gt: 0}}).count(), "A");
 assert.eq(1, t.find({a: {$gt: 0}}).toArray().length, "B");
diff --git a/jstests/core/multi2.js b/jstests/core/multi2.js
index 8c1c4ea5f3c..64473e4de98 100644
--- a/jstests/core/multi2.js
+++ b/jstests/core/multi2.js
@@ -10,13 +10,13 @@ t.save({});
 
 assert.eq(3, t.find({x: 1}).count(), "A");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 assert.eq(3, t.find({x: 1}).count(), "B");
 assert.eq(4, t.find().sort({x: 1, a: 1}).count(), "s1");
 assert.eq(1, t.find({x: 1, a: null}).count(), "B2");
 
 t.dropIndex({x: 1});
-t.ensureIndex({x: 1, a: 1});
+t.createIndex({x: 1, a: 1});
 assert.eq(3, t.find({x: 1}).count(), "C");  // SERVER-279
 assert.eq(4, t.find().sort({x: 1, a: 1}).count(), "s2");
 assert.eq(1, t.find({x: 1, a: null}).count(), "C2");
diff --git a/jstests/core/multikey_geonear.js b/jstests/core/multikey_geonear.js
index ad24afb0c98..4b1cd5eb482 100644
--- a/jstests/core/multikey_geonear.js
+++ b/jstests/core/multikey_geonear.js
@@ -16,7 +16,7 @@ function checkResults(cursor) {
     assert(!cursor.hasNext());
 }
 
-t.ensureIndex({a: 1, b: "2dsphere"});
+t.createIndex({a: 1, b: "2dsphere"});
 
 t.insert({_id: 0, a: 0, b: {type: "Point", coordinates: [0, 0]}});
 t.insert({_id: 1, a: 0, b: {type: "Point", coordinates: [1, 1]}});
@@ -33,7 +33,7 @@ checkResults(cursor);
 
 // Repeat these tests for a 2d index.
 t.drop();
-t.ensureIndex({a: "2d", b: 1});
+t.createIndex({a: "2d", b: 1});
 t.insert({_id: 0, a: [0, 0], b: 0});
 t.insert({_id: 1, a: [1, 1], b: 1});
 t.insert({_id: 2, a: [2, 2], b: 2});
@@ -47,7 +47,7 @@ checkResults(cursor);
 
 // The fields in the compound 2dsphere index share a prefix.
 t.drop();
-t.ensureIndex({"a.b": 1, "a.c": "2dsphere"});
+t.createIndex({"a.b": 1, "a.c": "2dsphere"});
 t.insert({_id: 0, a: [{b: 0}, {c: {type: "Point", coordinates: [0, 0]}}]});
 t.insert({_id: 1, a: [{b: 1}, {c: {type: "Point", coordinates: [1, 1]}}]});
 t.insert({_id: 2, a: [{b: 2}, {c: {type: "Point", coordinates: [2, 2]}}]});
@@ -66,7 +66,7 @@ assert(!cursor.hasNext());
 
 // The fields in the compound 2d index share a prefix.
 t.drop();
-t.ensureIndex({"a.b": "2d", "a.c": 1});
+t.createIndex({"a.b": "2d", "a.c": 1});
 t.insert({_id: 0, a: [{b: [0, 0]}, {c: 0}]});
 t.insert({_id: 1, a: [{b: [1, 1]}, {c: 1}]});
 t.insert({_id: 2, a: [{b: [2, 2]}, {c: 2}]});
diff --git a/jstests/core/ne1.js b/jstests/core/ne1.js
index 2128bd3a936..5069637eb30 100644
--- a/jstests/core/ne1.js
+++ b/jstests/core/ne1.js
@@ -6,5 +6,5 @@ t.save({x: 2});
 t.save({x: 3});
 
 assert.eq(2, t.find({x: {$ne: 2}}).itcount(), "A");
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 assert.eq(2, t.find({x: {$ne: 2}}).itcount(), "B");
diff --git a/jstests/core/ne2.js b/jstests/core/ne2.js
index db2ee7b01e5..5fef4f1d630 100644
--- a/jstests/core/ne2.js
+++ b/jstests/core/ne2.js
@@ -5,7 +5,7 @@
 
 t = db.jstests_ne2;
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 t.save({a: -0.5});
 t.save({a: 0});
diff --git a/jstests/core/nestedarr1.js b/jstests/core/nestedarr1.js
index 7edef9db512..248a70b5f78 100644
--- a/jstests/core/nestedarr1.js
+++ b/jstests/core/nestedarr1.js
@@ -21,7 +21,7 @@ function makeNestArr(depth) {
 let collection = db.arrNestTest;
 collection.drop();
 
-assert.commandWorked(collection.ensureIndex({a: 1}));
+assert.commandWorked(collection.createIndex({a: 1}));
 
 const kMaxDocumentDepthSoftLimit = 100;
 const kJavaScriptMaxDepthLimit = 150;
diff --git a/jstests/core/nestedobj1.js b/jstests/core/nestedobj1.js
index 44fdd4599d7..ba97f326934 100644
--- a/jstests/core/nestedobj1.js
+++ b/jstests/core/nestedobj1.js
@@ -19,7 +19,7 @@ function makeNestObj(depth) {
 let collection = db.objNestTest;
 collection.drop();
 
-assert.commandWorked(collection.ensureIndex({a: 1}));
+assert.commandWorked(collection.createIndex({a: 1}));
 
 const kMaxDocumentDepthSoftLimit = 100;
 const kJavaScriptMaxDepthLimit = 150;
diff --git a/jstests/core/nin.js b/jstests/core/nin.js
index d8a254357ba..b9887e48828 100644
--- a/jstests/core/nin.js
+++ b/jstests/core/nin.js
@@ -57,5 +57,5 @@ doTest = function(n) {
 
 doTest("no index");
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 doTest("with index");
diff --git a/jstests/core/not1.js b/jstests/core/not1.js
index 1039ae7c910..0726895ebbd 100644
--- a/jstests/core/not1.js
+++ b/jstests/core/not1.js
@@ -16,5 +16,5 @@ function test(name) {
 }
 
 test("no index");
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test("with index");
diff --git a/jstests/core/not2.js b/jstests/core/not2.js
index 0cd9209ce2d..31b2efcfa02 100644
--- a/jstests/core/not2.js
+++ b/jstests/core/not2.js
@@ -86,6 +86,6 @@ function doTest() {
 doTest();
 
 // Run the test with an index present.
-assert.commandWorked(coll.ensureIndex({i: 1}));
+assert.commandWorked(coll.createIndex({i: 1}));
 doTest();
 }());
diff --git a/jstests/core/not3.js b/jstests/core/not3.js
index 9f3014f2c1a..eac6bf8f047 100644
--- a/jstests/core/not3.js
+++ b/jstests/core/not3.js
@@ -4,7 +4,7 @@
 var t = db.jstests_not3;
 t.drop();
 
-t.ensureIndex({arr: 1});
+t.createIndex({arr: 1});
 t.save({_id: 0, arr: [1, 2, 3]});
 t.save({_id: 1, arr: [10, 11]});
 
diff --git a/jstests/core/notablescan.js b/jstests/core/notablescan.js
index eca1bd2e787..adad7f1b725 100644
--- a/jstests/core/notablescan.js
+++ b/jstests/core/notablescan.js
@@ -44,7 +44,7 @@ try {
     assert.includes(err.toString(),
                     "hint $natural is not allowed, because 'notablescan' is enabled");
 
-    t.ensureIndex({a: 1});
+    t.createIndex({a: 1});
     assert.eq(0, t.find({a: 1, b: 1}).itcount());
     assert.eq(1, t.find({a: 1, b: null}).itcount());
 
diff --git a/jstests/core/numberlong2.js b/jstests/core/numberlong2.js
index 4eadb744131..dad87fe30aa 100644
--- a/jstests/core/numberlong2.js
+++ b/jstests/core/numberlong2.js
@@ -8,7 +8,7 @@
 t = db.jstests_numberlong2;
 t.drop();
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 function chk(longNum) {
     t.remove({});
diff --git a/jstests/core/numberlong4.js b/jstests/core/numberlong4.js
index f81a9599e21..d7d73898b34 100644
--- a/jstests/core/numberlong4.js
+++ b/jstests/core/numberlong4.js
@@ -6,7 +6,7 @@ t.drop();
 
 if (0) {  // SERVER-3719
 
-    t.ensureIndex({x: 1});
+    t.createIndex({x: 1});
 
     Random.setRandomSeed();
 
diff --git a/jstests/core/or1.js b/jstests/core/or1.js
index c5975a058f2..d90947d5f87 100644
--- a/jstests/core/or1.js
+++ b/jstests/core/or1.js
@@ -61,13 +61,13 @@ doTest();
 
 // not part of SERVER-1003, but good check for subseq. implementations
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({b: 1});
+t.createIndex({b: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 doTest();
diff --git a/jstests/core/or2.js b/jstests/core/or2.js
index 5b520197eba..508b3294931 100644
--- a/jstests/core/or2.js
+++ b/jstests/core/or2.js
@@ -72,17 +72,17 @@ doTest = function(index) {
 
 doTest(false);
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({x: 1, a: 1});
+t.createIndex({x: 1, a: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({x: 1, b: 1});
+t.createIndex({x: 1, b: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({x: 1, a: 1, b: 1});
+t.createIndex({x: 1, a: 1, b: 1});
 doTest();
diff --git a/jstests/core/or3.js b/jstests/core/or3.js
index 22a26d571ca..26628927c87 100644
--- a/jstests/core/or3.js
+++ b/jstests/core/or3.js
@@ -63,17 +63,17 @@ doTest = function(index) {
 
 doTest(false);
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({x: 1, a: 1});
+t.createIndex({x: 1, a: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({x: 1, b: 1});
+t.createIndex({x: 1, b: 1});
 doTest();
 
 t.drop();
-t.ensureIndex({x: 1, a: 1, b: 1});
+t.createIndex({x: 1, a: 1, b: 1});
 doTest();
diff --git a/jstests/core/or4.js b/jstests/core/or4.js
index f065ccbec86..e095eb9961c 100644
--- a/jstests/core/or4.js
+++ b/jstests/core/or4.js
@@ -14,8 +14,8 @@ const coll = db.or4;
 coll.drop();
 db.getCollection("mrOutput").drop();
 
-coll.ensureIndex({a: 1});
-coll.ensureIndex({b: 1});
+coll.createIndex({a: 1});
+coll.createIndex({b: 1});
 
 assert.commandWorked(coll.insert({a: 2}));
 assert.commandWorked(coll.insert({b: 3}));
diff --git a/jstests/core/or5.js b/jstests/core/or5.js
index 40d7792eeeb..eed4c3fc62d 100644
--- a/jstests/core/or5.js
+++ b/jstests/core/or5.js
@@ -6,10 +6,10 @@
 t = db.jstests_or5;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
-t.ensureIndex({c: 1});
+t.createIndex({c: 1});
 
 t.save({a: 2});
 t.save({b: 3});
@@ -36,7 +36,7 @@ for (i = 2; i <= 7; ++i) {
     assert.eq.automsg("6", "t.find( {$or:[{a:2},{b:3},{c:6}]} ).batchSize( i ).toArray().length");
 }
 
-t.ensureIndex({z: "2d"});
+t.createIndex({z: "2d"});
 
 assert.throws.automsg(function() {
                  return t.find({$or: [{z: {$near: [50, 50]}}, {a: 2}]}).toArray();
@@ -45,9 +45,9 @@ assert.throws.automsg(function() {
 function reset() {
     t.drop();
 
-    t.ensureIndex({a: 1});
-    t.ensureIndex({b: 1});
-    t.ensureIndex({c: 1});
+    t.createIndex({a: 1});
+    t.createIndex({b: 1});
+    t.createIndex({c: 1});
 
     t.save({a: 2});
     t.save({a: 2});
diff --git a/jstests/core/or6.js b/jstests/core/or6.js
index 144f9ed7e9e..7b18e1c219a 100644
--- a/jstests/core/or6.js
+++ b/jstests/core/or6.js
@@ -6,8 +6,8 @@
 var t = db.jstests_orq;
 t.drop();
 
-t.ensureIndex({a: 1, c: 1});
-t.ensureIndex({b: 1, c: 1});
+t.createIndex({a: 1, c: 1});
+t.createIndex({b: 1, c: 1});
 
 t.save({a: 1, c: 9});
 t.save({a: 1, c: 10});
diff --git a/jstests/core/or7.js b/jstests/core/or7.js
index d824a90aa81..e639a195739 100644
--- a/jstests/core/or7.js
+++ b/jstests/core/or7.js
@@ -3,7 +3,7 @@
 t = db.jstests_or7;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: 2});
 
 assert.eq.automsg("1", "t.count( {$or:[{a:{$in:[1,3]}},{a:2}]} )");
diff --git a/jstests/core/or8.js b/jstests/core/or8.js
index 41537dbdf83..4af81ec4829 100644
--- a/jstests/core/or8.js
+++ b/jstests/core/or8.js
@@ -14,7 +14,7 @@ t.find({"$or": [{"PropA": {"$lt": "b"}}, {"PropA": {"$lt": "b", "$gt": "a"}}]}).
 
 t.save({a: 1});
 t.save({a: 3});
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.find({$or: [{a: {$in: []}}]}).toArray();
 assert.eq.automsg("2", "t.find({ $or: [ { a: {$in:[]} }, {a:1}, {a:3} ] } ).toArray().length");
 assert.eq.automsg("2", "t.find({ $or: [ {a:1}, { a: {$in:[]} }, {a:3} ] } ).toArray().length");
@@ -24,8 +24,8 @@ assert.eq.automsg("2", "t.find({ $or: [ {a:1}, {a:3}, { a: {$in:[]} } ] } ).toAr
 
 t.drop();
 t.save({a: {b: 1, c: 1}});
-t.ensureIndex({'a.b': 1});
-t.ensureIndex({'a.c': 1});
+t.createIndex({'a.b': 1});
+t.createIndex({'a.c': 1});
 assert.eq(1, t.find({$or: [{'a.b': 1}, {'a.c': 1}]}).itcount());
 
 t.remove({});
diff --git a/jstests/core/or9.js b/jstests/core/or9.js
index 68814c684cb..4938e84ca04 100644
--- a/jstests/core/or9.js
+++ b/jstests/core/or9.js
@@ -5,7 +5,7 @@
 t = db.jstests_or9;
 t.drop();
 
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 
 t.save({a: 2, b: 2});
 
diff --git a/jstests/core/or_inexact.js b/jstests/core/or_inexact.js
index d6a51d66259..0584be98d6d 100644
--- a/jstests/core/or_inexact.js
+++ b/jstests/core/or_inexact.js
@@ -20,7 +20,7 @@ var cursor;
 
 // Case 1: An EXACT predicate and an INEXACT_COVERED
 t.drop();
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 t.insert({_id: 0, name: "thomas"});
 t.insert({_id: 1, name: "alexandra"});
 cursor = t.find({$or: [{name: "thomas"}, {name: /^alexand(er|ra)/}]});
@@ -28,7 +28,7 @@ assert.eq(2, cursor.itcount(), "case 1");
 
 // Case 2: Two INEXACT_COVERED predicates.
 t.drop();
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 t.insert({_id: 0, name: "thomas"});
 t.insert({_id: 1, name: "alexandra"});
 cursor = t.find({$or: [{name: /omas/}, {name: /^alexand(er|ra)/}]});
@@ -36,7 +36,7 @@ assert.eq(2, cursor.itcount(), "case 2");
 
 // Case 3: An EXACT, and INEXACT_COVERED, and an INEXACT_FETCH.
 t.drop();
-t.ensureIndex({names: 1});
+t.createIndex({names: 1});
 t.insert({_id: 0, names: ["thomas", "alexandra"]});
 t.insert({_id: 1, names: "frank"});
 t.insert({_id: 2, names: "alice"});
@@ -47,7 +47,7 @@ assert.eq(3, cursor.itcount(), "case 3");
 
 // Case 4: Two INEXACT_FETCH.
 t.drop();
-t.ensureIndex({names: 1});
+t.createIndex({names: 1});
 t.insert({_id: 0, names: ["thomas", "alexandra"]});
 t.insert({_id: 1, names: ["frank", "alice"]});
 t.insert({_id: 2, names: "frank"});
@@ -58,8 +58,8 @@ assert.eq(2, cursor.itcount(), "case 4");
 // Case 5: Two indices. One has EXACT and INEXACT_COVERED. The other
 // has EXACT and INEXACT_FETCH.
 t.drop();
-t.ensureIndex({first: 1});
-t.ensureIndex({last: 1});
+t.createIndex({first: 1});
+t.createIndex({last: 1});
 t.insert({_id: 0, first: "frank", last: "smith"});
 t.insert({_id: 1, first: "john", last: "doe"});
 t.insert({_id: 2, first: "dave", last: "st"});
@@ -71,7 +71,7 @@ assert.eq(4, cursor.itcount(), "case 5");
 
 // Case 6: Multikey with only EXACT predicates.
 t.drop();
-t.ensureIndex({names: 1});
+t.createIndex({names: 1});
 t.insert({_id: 0, names: ["david", "dave"]});
 t.insert({_id: 1, names: ["joseph", "joe", "joey"]});
 cursor = t.find({$or: [{names: "dave"}, {names: "joe"}]});
@@ -79,7 +79,7 @@ assert.eq(2, cursor.itcount(), "case 6");
 
 // Case 7: Multikey with EXACT and INEXACT_COVERED.
 t.drop();
-t.ensureIndex({names: 1});
+t.createIndex({names: 1});
 t.insert({_id: 0, names: ["david", "dave"]});
 t.insert({_id: 1, names: ["joseph", "joe", "joey"]});
 cursor = t.find({$or: [{names: "dave"}, {names: /joe/}]});
@@ -87,8 +87,8 @@ assert.eq(2, cursor.itcount(), "case 7");
 
 // Case 8: Text with EXACT.
 t.drop();
-t.ensureIndex({pre: 1, names: "text"});
-t.ensureIndex({other: 1});
+t.createIndex({pre: 1, names: "text"});
+t.createIndex({other: 1});
 t.insert({_id: 0, pre: 3, names: "david dave", other: 1});
 t.insert({_id: 1, pre: 4, names: "joseph joe joey", other: 2});
 cursor = t.find({$or: [{$text: {$search: "dave"}, pre: 3}, {other: 2}]});
@@ -96,8 +96,8 @@ assert.eq(2, cursor.itcount(), "case 8");
 
 // Case 9: Text with INEXACT_COVERED.
 t.drop();
-t.ensureIndex({pre: 1, names: "text"});
-t.ensureIndex({other: 1});
+t.createIndex({pre: 1, names: "text"});
+t.createIndex({other: 1});
 t.insert({_id: 0, pre: 3, names: "david dave", other: "foo"});
 t.insert({_id: 1, pre: 5, names: "david dave", other: "foo"});
 t.insert({_id: 2, pre: 4, names: "joseph joe joey", other: "bar"});
@@ -106,8 +106,8 @@ assert.eq(2, cursor.itcount(), "case 9");
 
 // Case 10: Text requiring filter with INEXACT_COVERED.
 t.drop();
-t.ensureIndex({pre: 1, names: "text"});
-t.ensureIndex({other: 1});
+t.createIndex({pre: 1, names: "text"});
+t.createIndex({other: 1});
 t.insert({_id: 0, pre: 3, names: "david dave", other: "foo"});
 t.insert({_id: 1, pre: 3, names: "david dave", other: "foo"});
 t.insert({_id: 2, pre: 4, names: "joseph joe joey", other: "bar"});
@@ -116,7 +116,7 @@ assert.eq(3, cursor.itcount(), "case 10");
 
 // Case 11: GEO with non-geo, same index, 2dsphere.
 t.drop();
-t.ensureIndex({pre: 1, loc: "2dsphere"});
+t.createIndex({pre: 1, loc: "2dsphere"});
 t.insert({_id: 0, pre: 3, loc: {type: "Point", coordinates: [40, 5]}});
 t.insert({_id: 1, pre: 4, loc: {type: "Point", coordinates: [0, 0]}});
 cursor = t.find({
@@ -149,7 +149,7 @@ assert.eq(2, cursor.itcount(), "case 11");
 
 // Case 12: GEO with non-geo, same index, 2d.
 t.drop();
-t.ensureIndex({pre: 1, loc: "2d"});
+t.createIndex({pre: 1, loc: "2d"});
 t.insert({_id: 0, pre: 3, loc: {type: "Point", coordinates: [40, 5]}});
 t.insert({_id: 1, pre: 4, loc: {type: "Point", coordinates: [0, 0]}});
 cursor = t.find({
@@ -182,7 +182,7 @@ assert.eq(2, cursor.itcount(), "case 12");
 
 // Case 13: $elemMatch object.
 t.drop();
-t.ensureIndex({"a.b": 1});
+t.createIndex({"a.b": 1});
 t.insert({_id: 0, a: [{b: 1}, {b: 2}]});
 t.insert({_id: 1, a: [{b: 3}, {b: 4}]});
 cursor = t.find({$or: [{a: {$elemMatch: {b: {$lte: 1}}}}, {a: {$elemMatch: {b: {$gte: 4}}}}]});
@@ -190,7 +190,7 @@ assert.eq(2, cursor.itcount(), "case 13");
 
 // Case 14: $elemMatch object, below an AND.
 t.drop();
-t.ensureIndex({"a.b": 1});
+t.createIndex({"a.b": 1});
 t.insert({_id: 0, a: [{b: 1}, {b: 2}]});
 t.insert({_id: 1, a: [{b: 2}, {b: 4}]});
 cursor =
@@ -199,7 +199,7 @@ assert.eq(2, cursor.itcount(), "case 14");
 
 // Case 15: $or below $elemMatch.
 t.drop();
-t.ensureIndex({"a.b": 1});
+t.createIndex({"a.b": 1});
 t.insert({_id: 0, a: [{b: 1}, {b: 2}]});
 t.insert({_id: 1, a: [{b: 2}, {b: 4}]});
 t.insert({_id: 2, a: {b: 4}});
@@ -208,7 +208,7 @@ assert.eq(2, cursor.itcount(), "case 15");
 
 // Case 16: $or below $elemMatch with INEXACT_COVERED.
 t.drop();
-t.ensureIndex({"a.b": 1});
+t.createIndex({"a.b": 1});
 t.insert({_id: 0, a: [{b: "x"}, {b: "y"}]});
 t.insert({_id: 1, a: [{b: "y"}, {b: ["y", "z"]}]});
 t.insert({_id: 2, a: {b: ["y", "z"]}});
@@ -217,7 +217,7 @@ assert.eq(2, cursor.itcount(), "case 16");
 
 // Case 17: case from SERVER-14030.
 t.drop();
-t.ensureIndex({number: 1});
+t.createIndex({number: 1});
 t.insert({number: null, user_id: 1});
 t.insert({number: 2, user_id: 1});
 t.insert({number: 1, user_id: 1});
@@ -226,7 +226,7 @@ assert.eq(3, cursor.itcount(), "case 17");
 
 // Case 18: $in with EXACT and INEXACT_COVERED.
 t.drop();
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 t.insert({_id: 0, name: "thomas"});
 t.insert({_id: 1, name: "alexandra"});
 cursor = t.find({name: {$in: ["thomas", /^alexand(er|ra)/]}});
@@ -234,7 +234,7 @@ assert.eq(2, cursor.itcount(), "case 18");
 
 // Case 19: $in with EXACT, INEXACT_COVERED, and INEXACT_FETCH.
 t.drop();
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 t.insert({_id: 0, name: "thomas"});
 t.insert({_id: 1, name: "alexandra"});
 t.insert({_id: 2});
@@ -243,8 +243,8 @@ assert.eq(3, cursor.itcount(), "case 19");
 
 // Case 20: $in with EXACT, INEXACT_COVERED, and INEXACT_FETCH, two indices.
 t.drop();
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 t.insert({_id: 0, a: "x", b: "y"});
 t.insert({_id: 1, a: "z", b: "z"});
 t.insert({_id: 2});
@@ -256,7 +256,7 @@ assert.eq(5, cursor.itcount(), "case 19");
 
 // Case 21: two $geoWithin that collapse to a single GEO index scan.
 t.drop();
-t.ensureIndex({loc: "2dsphere"});
+t.createIndex({loc: "2dsphere"});
 t.insert({_id: 0, loc: {type: "Point", coordinates: [40, 5]}});
 t.insert({_id: 1, loc: {type: "Point", coordinates: [0, 0]}});
 cursor = t.find({
diff --git a/jstests/core/ora.js b/jstests/core/ora.js
index 06d8f39c48f..ca07516cae3 100644
--- a/jstests/core/ora.js
+++ b/jstests/core/ora.js
@@ -19,7 +19,7 @@ assert.eq.automsg("10", "t.find({$or: [{$where: 'this.x === 2'}, {x: {$ne: 2}}]}
 
 // geo
 t.drop();
-t.ensureIndex({loc: "2d"});
+t.createIndex({loc: "2d"});
 
 assert.throws(function() {
     t.find({$or: [{loc: {$near: [11, 11]}}]}).limit(1).next();
diff --git a/jstests/core/orb.js b/jstests/core/orb.js
index 345ac92d26e..aa75bb97e0b 100644
--- a/jstests/core/orb.js
+++ b/jstests/core/orb.js
@@ -4,14 +4,14 @@ var t = db.jstests_orb;
 t.drop();
 
 t.save({a: 1});
-t.ensureIndex({a: -1});
+t.createIndex({a: -1});
 
 assert.eq.automsg("1", "t.count( {$or: [ { a: { $gt:0,$lt:2 } }, { a: { $gt:-1,$lt:3 } } ] } )");
 
 t.drop();
 
 t.save({a: 1, b: 1});
-t.ensureIndex({a: 1, b: -1});
+t.createIndex({a: 1, b: -1});
 
 assert.eq.automsg("1", "t.count( {$or: [ { a: { $gt:0,$lt:2 } }, { a: { $gt:-1,$lt:3 } } ] } )");
 assert.eq.automsg(
diff --git a/jstests/core/orc.js b/jstests/core/orc.js
index dc46d6de4ad..001d6f4bc9f 100644
--- a/jstests/core/orc.js
+++ b/jstests/core/orc.js
@@ -20,7 +20,7 @@ t.drop();
 // possible to write a more
 // robust test.
 
-t.ensureIndex({a: -1, b: 1, c: 1});
+t.createIndex({a: -1, b: 1, c: 1});
 
 // sanity test
 t.save({a: null, b: 4, c: 4});
diff --git a/jstests/core/ord.js b/jstests/core/ord.js
index ddbae540ffc..4a76f831246 100644
--- a/jstests/core/ord.js
+++ b/jstests/core/ord.js
@@ -16,8 +16,8 @@ load("jstests/libs/fixture_helpers.js");  // For FixtureHelpers.
 const t = db.jstests_ord;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 for (let i = 0; i < 80; ++i) {
     t.save({a: 1});
diff --git a/jstests/core/ore.js b/jstests/core/ore.js
index 959f43f5101..756db6215c5 100644
--- a/jstests/core/ore.js
+++ b/jstests/core/ore.js
@@ -4,8 +4,8 @@
 t = db.jstests_ore;
 t.drop();
 
-t.ensureIndex({a: -1});
-t.ensureIndex({b: 1});
+t.createIndex({a: -1});
+t.createIndex({b: 1});
 
 t.save({a: 1, b: 1});
 t.save({a: 2, b: 1});
diff --git a/jstests/core/org.js b/jstests/core/org.js
index 7479db062e4..0c6808330c8 100644
--- a/jstests/core/org.js
+++ b/jstests/core/org.js
@@ -5,8 +5,8 @@
 t = db.jstests_org;
 t.drop();
 
-t.ensureIndex({a: 1}, {sparse: true});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1}, {sparse: true});
+t.createIndex({b: 1});
 
 t.remove({});
 t.save({a: 1, b: 2});
diff --git a/jstests/core/orh.js b/jstests/core/orh.js
index 1ceed1d501f..91ce121e5a4 100644
--- a/jstests/core/orh.js
+++ b/jstests/core/orh.js
@@ -5,8 +5,8 @@
 t = db.jstests_orh;
 t.drop();
 
-t.ensureIndex({a: 1}, {sparse: true});
-t.ensureIndex({b: 1, a: 1});
+t.createIndex({a: 1}, {sparse: true});
+t.createIndex({b: 1, a: 1});
 
 t.remove({});
 t.save({b: 2});
diff --git a/jstests/core/orj.js b/jstests/core/orj.js
index 0ec304d9e52..deee0c4821c 100644
--- a/jstests/core/orj.js
+++ b/jstests/core/orj.js
@@ -84,26 +84,26 @@ function check() {
 
 check();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 check();
 t.dropIndexes();
 
-t.ensureIndex({b: 1});
+t.createIndex({b: 1});
 check();
 t.dropIndexes();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 check();
 t.dropIndexes();
 
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 check();
 t.dropIndexes();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
+t.createIndex({a: 1, b: 1});
 check();
 
 function checkHinted(hint) {
diff --git a/jstests/core/ork.js b/jstests/core/ork.js
index 7f203c74e5f..9079d3819ba 100644
--- a/jstests/core/ork.js
+++ b/jstests/core/ork.js
@@ -6,7 +6,7 @@
 t = db.jstests_ork;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: [1, 2], b: 5});
 t.save({a: [2, 4], b: 5});
 
diff --git a/jstests/core/oro.js b/jstests/core/oro.js
index 80684869f6d..aa884d306c6 100644
--- a/jstests/core/oro.js
+++ b/jstests/core/oro.js
@@ -13,7 +13,7 @@ orClauses = [];
 for (idxKey = 'a'; idxKey <= 'aaaaaaaaaa'; idxKey += 'a') {
     idx = {};
     idx[idxKey] = 1;
-    t.ensureIndex(idx);
+    t.createIndex(idx);
     for (i = 0; i < 200; ++i) {
         t.insert(idx);
     }
diff --git a/jstests/core/orp.js b/jstests/core/orp.js
index a706d6f4c1a..a2918fc5a56 100644
--- a/jstests/core/orp.js
+++ b/jstests/core/orp.js
@@ -4,9 +4,9 @@
 t = db.jstests_orp;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
-t.ensureIndex({c: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
+t.createIndex({c: 1});
 
 for (i = 0; i < 200; ++i) {
     t.save({a: 1, b: 1});
@@ -23,7 +23,7 @@ assert.eq(201, t.count({$or: [{a: 1}, {c: 1}, {b: 1}]}));
 // Deduping results that would normally be index only matches on overlapping and double scanned $or
 // field regions.
 t.drop();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 for (i = 0; i < 16; ++i) {
     for (j = 0; j < 16; ++j) {
         t.save({a: i, b: j});
@@ -33,8 +33,8 @@ assert.eq(16 * 16, t.count({$or: [{a: {$gte: 0}, b: {$gte: 0}}, {a: {$lte: 16},
 
 // Deduping results from a clause that completed before the multi cursor takeover.
 t.drop();
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 t.save({a: 1, b: 200});
 for (i = 0; i < 200; ++i) {
     t.save({b: i});
diff --git a/jstests/core/profile_list_indexes.js b/jstests/core/profile_list_indexes.js
index 359dd9e85cf..92389bf5642 100644
--- a/jstests/core/profile_list_indexes.js
+++ b/jstests/core/profile_list_indexes.js
@@ -19,7 +19,7 @@ const numIndexes = 5;
 for (let i = 0; i < numIndexes; ++i) {
     let indexSpec = {};
     indexSpec["fakeField_" + i] = 1;
-    assert.commandWorked(testColl.ensureIndex(indexSpec));
+    assert.commandWorked(testColl.createIndex(indexSpec));
 }
 
 testDB.setProfilingLevel(2);
diff --git a/jstests/core/proj_key1.js b/jstests/core/proj_key1.js
index af6d6d9d9fe..51ca23d0c37 100644
--- a/jstests/core/proj_key1.js
+++ b/jstests/core/proj_key1.js
@@ -13,7 +13,7 @@ for (i = 0; i < 10; i++) {
     t.insert({a: i, b: i});
 }
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(as, t.find({a: {$gte: 0}}, {a: 1, _id: 0}).sort({a: 1}).toArray());
 assert.eq(as, t.find({a: {$gte: 0}}, {a: 1, _id: 0}).sort({a: 1}).batchSize(2).toArray());
diff --git a/jstests/core/queryoptimizera.js b/jstests/core/queryoptimizera.js
index 5daccbba232..55d0d5c424a 100644
--- a/jstests/core/queryoptimizera.js
+++ b/jstests/core/queryoptimizera.js
@@ -83,7 +83,7 @@ t.find({_id: 0, a: 0}).itcount();
 assertNoNewWarnings();
 
 // Warnings should not be printed when an index is added on _id.
-t.ensureIndex({_id: 1});
+t.createIndex({_id: 1});
 
 t.find({_id: 0}).itcount();
 assertNoNewWarnings();
diff --git a/jstests/core/record_store_count.js b/jstests/core/record_store_count.js
index 89dcf8d4cdc..f89f1cfea17 100644
--- a/jstests/core/record_store_count.js
+++ b/jstests/core/record_store_count.js
@@ -15,7 +15,7 @@ coll.drop();
 assert.commandWorked(coll.insert({x: 0}));
 assert.commandWorked(coll.insert({x: 1}));
 
-assert.commandWorked(coll.ensureIndex({x: 1}));
+assert.commandWorked(coll.createIndex({x: 1}));
 
 //
 // Logically empty predicates should use the record store's count.
@@ -78,7 +78,7 @@ const kNewIndexSpec = {
     x: 1,
     _id: 1
 };
-assert.commandWorked(coll.ensureIndex(kNewIndexSpec));
+assert.commandWorked(coll.createIndex(kNewIndexSpec));
 testExplainAndExpectStage({
     expectedStages: ["COUNT", "SHARDING_FILTER"],
     unexpectedStages: ["FETCH"],
diff --git a/jstests/core/regex3.js b/jstests/core/regex3.js
index 46b18c03028..158d0607647 100644
--- a/jstests/core/regex3.js
+++ b/jstests/core/regex3.js
@@ -14,7 +14,7 @@ t.save({name: "aaron"});
 assert.eq(2, t.find({name: /^e.*/}).itcount(), "no index count");
 assert.eq(
     4, t.find({name: /^e.*/}).explain(true).executionStats.totalDocsExamined, "no index explain");
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 assert.eq(2, t.find({name: /^e.*/}).itcount(), "index count");
 assert.eq(2,
           t.find({name: /^e.*/}).explain(true).executionStats.totalKeysExamined,
@@ -28,7 +28,7 @@ t.save({name: "ac"});
 t.save({name: "c"});
 
 assert.eq(3, t.find({name: /^aa*/}).itcount(), "B ni");
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 assert.eq(3, t.find({name: /^aa*/}).itcount(), "B i 1");
 assert.eq(4, t.find({name: /^aa*/}).explain(true).executionStats.totalKeysExamined, "B i 1 e");
 
@@ -39,5 +39,5 @@ t.drop();
 
 t.save({name: ""});
 assert.eq(1, t.find({name: /^a?/}).itcount(), "C 1");
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 assert.eq(1, t.find({name: /^a?/}).itcount(), "C 2");
diff --git a/jstests/core/regex4.js b/jstests/core/regex4.js
index 4ced6d06924..0e631082352 100644
--- a/jstests/core/regex4.js
+++ b/jstests/core/regex4.js
@@ -17,7 +17,7 @@ assert.eq(
 // assert.eq( 2 , t.find( { name : { $ne : /^e.*/ } } ).count() , "no index count ne" ); //
 // SERVER-251
 
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 
 assert.eq(2, t.find({name: /^e.*/}).count(), "index count");
 assert.eq(2,
diff --git a/jstests/core/regex5.js b/jstests/core/regex5.js
index 69537e149e5..d0836a62686 100644
--- a/jstests/core/regex5.js
+++ b/jstests/core/regex5.js
@@ -31,7 +31,7 @@ doit = function() {
 };
 
 doit();
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 print("now indexed");
 doit();
 
diff --git a/jstests/core/regex6.js b/jstests/core/regex6.js
index 7af6c7d8400..f21152d8c55 100644
--- a/jstests/core/regex6.js
+++ b/jstests/core/regex6.js
@@ -14,7 +14,7 @@ t.save({name: "bob"});
 t.save({name: "aaron"});
 t.save({name: "[with]some?symbols"});
 
-t.ensureIndex({name: 1});
+t.createIndex({name: 1});
 
 assert.eq(0, t.find({name: /^\//}).count(), "index count");
 assert.eq(
diff --git a/jstests/core/regex7.js b/jstests/core/regex7.js
index 290cbe387a9..f864f29be8e 100644
--- a/jstests/core/regex7.js
+++ b/jstests/core/regex7.js
@@ -17,7 +17,7 @@ assert.eq(/^b/, t.findOne({r: /^b/}).r, '3 1 a');
 assert.eq(1, t.count({r: /^b/}), '3 2 a');
 
 // with index
-t.ensureIndex({r: 1});
+t.createIndex({r: 1});
 assert.eq(/^a/, t.findOne({r: /^a/}).r, '1 1 b');
 assert.eq(1, t.count({r: /^a/}), '1 2 b');
 assert.eq(/^a/i, t.findOne({r: /^a/i}).r, '2 1 b');
diff --git a/jstests/core/regex8.js b/jstests/core/regex8.js
index c92e82e4aa6..d65a6836b26 100644
--- a/jstests/core/regex8.js
+++ b/jstests/core/regex8.js
@@ -20,5 +20,5 @@ function test(msg) {
 
 test("A");
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test("B");
diff --git a/jstests/core/regex_embed1.js b/jstests/core/regex_embed1.js
index baaa8937962..c74ffb4aa32 100644
--- a/jstests/core/regex_embed1.js
+++ b/jstests/core/regex_embed1.js
@@ -23,5 +23,5 @@ function test(m) {
 
 test("A");
 
-t.ensureIndex({"a.x": 1});
+t.createIndex({"a.x": 1});
 test("B");
diff --git a/jstests/core/regexa.js b/jstests/core/regexa.js
index b56e2cf405e..694436e87a8 100644
--- a/jstests/core/regexa.js
+++ b/jstests/core/regexa.js
@@ -13,7 +13,7 @@ function check() {
 t.save({a: 'a'});
 
 check();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 if (1) {  // SERVER-3298
     check();
 }
diff --git a/jstests/core/regexc.js b/jstests/core/regexc.js
index d7df4f7d574..e9e2ba613aa 100644
--- a/jstests/core/regexc.js
+++ b/jstests/core/regexc.js
@@ -7,7 +7,7 @@ var t = db.jstests_regexc;
 
 // $and using same index twice
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: "0"});
 t.save({a: "1"});
 t.save({a: "10"});
@@ -15,7 +15,7 @@ assert.eq(1, t.find({$and: [{a: /0/}, {a: /1/}]}).itcount());
 
 // implicit $and using compound index twice
 t.drop();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 t.save({a: "0", b: "1"});
 t.save({a: "10", b: "10"});
 t.save({a: "10", b: "2"});
@@ -23,7 +23,7 @@ assert.eq(2, t.find({a: /0/, b: /1/}).itcount());
 
 // $or using same index twice
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({a: "0"});
 t.save({a: "1"});
 t.save({a: "2"});
diff --git a/jstests/core/remove.js b/jstests/core/remove.js
index 37754c74190..f08792aeca5 100644
--- a/jstests/core/remove.js
+++ b/jstests/core/remove.js
@@ -6,7 +6,7 @@
 t = db.removetest;
 
 function f(n, dir) {
-    t.ensureIndex({x: dir || 1});
+    t.createIndex({x: dir || 1});
     for (i = 0; i < n; i++)
         t.save({x: 3, z: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"});
 
diff --git a/jstests/core/remove2.js b/jstests/core/remove2.js
index d01c1e2e58c..4193b8dd11f 100644
--- a/jstests/core/remove2.js
+++ b/jstests/core/remove2.js
@@ -38,10 +38,10 @@ f();
 t.drop();
 g();
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 t.remove({});
 f();
 t.drop();
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 g();
 })();
diff --git a/jstests/core/remove6.js b/jstests/core/remove6.js
index b91d28fa4e5..f60200a8d81 100644
--- a/jstests/core/remove6.js
+++ b/jstests/core/remove6.js
@@ -23,7 +23,7 @@ function test(n, idx) {
     pop();
     assert.eq(N, t.count(), n + " A " + idx);
     if (idx)
-        t.ensureIndex(idx);
+        t.createIndex(idx);
     var res = del();
     assert(!res.hasWriteError(), "error deleting: " + res.toString());
     assert.eq(0, t.count(), n + " B " + idx);
diff --git a/jstests/core/remove7.js b/jstests/core/remove7.js
index 4a1548fbce2..9cc86329990 100644
--- a/jstests/core/remove7.js
+++ b/jstests/core/remove7.js
@@ -18,7 +18,7 @@ for (i = 0; i < 1000; i++) {
     t.save({tags: getTags()});
 }
 
-t.ensureIndex({tags: 1});
+t.createIndex({tags: 1});
 
 for (i = 0; i < 200; i++) {
     for (var j = 0; j < 10; j++)
diff --git a/jstests/core/remove9.js b/jstests/core/remove9.js
index dc3f84a9c34..4962dd9a06f 100644
--- a/jstests/core/remove9.js
+++ b/jstests/core/remove9.js
@@ -13,7 +13,7 @@
 
 const t = db.jstests_remove9;
 t.drop();
-t.ensureIndex({i: 1});
+t.createIndex({i: 1});
 
 const bulk = t.initializeUnorderedBulkOp();
 for (let i = 0; i < 1000; ++i) {
diff --git a/jstests/core/removea.js b/jstests/core/removea.js
index 2c45ee665f4..9fd489b7005 100644
--- a/jstests/core/removea.js
+++ b/jstests/core/removea.js
@@ -10,7 +10,7 @@ Random.setRandomSeed();
 
 for (let v = 0; v < 2; ++v) {  // Try each index version.
     t.drop();
-    t.ensureIndex({a: 1}, {v: v});
+    t.createIndex({a: 1}, {v: v});
     const S = 100;
     const B = 100;
     for (let x = 0; x < S; x++) {
diff --git a/jstests/core/removeb.js b/jstests/core/removeb.js
index b81c0818d21..d4ea12aa8f6 100644
--- a/jstests/core/removeb.js
+++ b/jstests/core/removeb.js
@@ -13,7 +13,7 @@
 const t = db.jstests_removeb;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 // Make the index multikey to trigger cursor dedup checking.
 t.insert({a: [-1, -2]});
diff --git a/jstests/core/removec.js b/jstests/core/removec.js
index 500437e8891..560f7405de3 100644
--- a/jstests/core/removec.js
+++ b/jstests/core/removec.js
@@ -8,7 +8,7 @@
 
 t = db.jstests_removec;
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 /** @return an array containing a sequence of numbers from i to i + 10. */
 function runStartingWith(i) {
diff --git a/jstests/core/rename.js b/jstests/core/rename.js
index 08d254bbe29..a8d888393b5 100644
--- a/jstests/core/rename.js
+++ b/jstests/core/rename.js
@@ -12,8 +12,8 @@ c.drop();
 
 a.save({a: 1});
 a.save({a: 2});
-a.ensureIndex({a: 1});
-a.ensureIndex({b: 1});
+a.createIndex({a: 1});
+a.createIndex({b: 1});
 
 c.save({a: 100});
 assert.commandFailed(
diff --git a/jstests/core/rename4.js b/jstests/core/rename4.js
index 1ce3b30f177..98a9dd80d11 100644
--- a/jstests/core/rename4.js
+++ b/jstests/core/rename4.js
@@ -124,7 +124,7 @@ good({a: 1, c: 4}, {$rename: {b: 'c.d'}}, {a: 1, c: 4});
 
 // check index
 t.drop();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 function l(start, mod, query, expected) {
     t.remove({});
diff --git a/jstests/core/rename5.js b/jstests/core/rename5.js
index 357d67fc9ee..3d5646c7ee5 100644
--- a/jstests/core/rename5.js
+++ b/jstests/core/rename5.js
@@ -5,7 +5,7 @@
 t = db.jstests_rename5;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 t.save({b: 1});
 
 t.update({}, {$rename: {a: 'b'}});
diff --git a/jstests/core/rename6.js b/jstests/core/rename6.js
index faa36a448dd..1122623c165 100644
--- a/jstests/core/rename6.js
+++ b/jstests/core/rename6.js
@@ -17,7 +17,7 @@ const dbd = testDB.getCollection(d);
 dbc.drop();
 dbd.drop();
 
-dbc.ensureIndex({
+dbc.createIndex({
     "name": 1,
     "date": 1,
     "time": 1,
diff --git a/jstests/core/rename7.js b/jstests/core/rename7.js
index 8f209e83acd..a538f36e2dc 100644
--- a/jstests/core/rename7.js
+++ b/jstests/core/rename7.js
@@ -28,8 +28,8 @@ b.drop();
 a.save({a: 1});
 a.save({a: 2});
 a.save({a: 3});
-a.ensureIndex({a: 1});
-a.ensureIndex({b: 1});
+a.createIndex({a: 1});
+a.createIndex({b: 1});
 
 assert.commandWorked(admin.runCommand({renameCollection: "db_a.rename7", to: "db_b.rename7"}));
 
diff --git a/jstests/core/return_key.js b/jstests/core/return_key.js
index 9d30477bd54..96c6284ebf4 100644
--- a/jstests/core/return_key.js
+++ b/jstests/core/return_key.js
@@ -24,8 +24,8 @@ assert.commandWorked(coll.insert({a: 1, b: 3}));
 assert.commandWorked(coll.insert({a: 2, b: 2}));
 assert.commandWorked(coll.insert({a: 3, b: 1}));
 
-assert.commandWorked(coll.ensureIndex({a: 1}));
-assert.commandWorked(coll.ensureIndex({b: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
+assert.commandWorked(coll.createIndex({b: 1}));
 
 // Basic returnKey.
 results = coll.find().hint({a: 1}).sort({a: 1}).returnKey().toArray();
diff --git a/jstests/core/server14747.js b/jstests/core/server14747.js
index f9a650defa4..c792f214259 100644
--- a/jstests/core/server14747.js
+++ b/jstests/core/server14747.js
@@ -10,8 +10,8 @@
 var t = db.jstests_server14747;
 
 t.drop();
-t.ensureIndex({a: 1, b: 1});
-t.ensureIndex({a: 1, c: 1});
+t.createIndex({a: 1, b: 1});
+t.createIndex({a: 1, c: 1});
 t.insert({a: 1});
 for (var i = 0; i < 10; i++) {
     t.find({a: 1}).explain(true);
diff --git a/jstests/core/server14753.js b/jstests/core/server14753.js
index e8de183f2d7..4fac2e06485 100644
--- a/jstests/core/server14753.js
+++ b/jstests/core/server14753.js
@@ -7,8 +7,8 @@
 var t = db.jstests_server14753;
 
 t.drop();
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 for (var i = 0; i < 20; i++) {
     t.insert({b: i});
 }
diff --git a/jstests/core/server9547.js b/jstests/core/server9547.js
index 66b17644e15..5e2d6aba566 100644
--- a/jstests/core/server9547.js
+++ b/jstests/core/server9547.js
@@ -8,7 +8,7 @@ for (var i = 0; i < 10; i++) {
     t.save({a: i});
 }
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 // note: max() value is exclusive upper bound
 assert.eq(4, t.find({}).max({a: 4}).hint({a: 1}).toArray().length, "no order");
diff --git a/jstests/core/set_type_change.js b/jstests/core/set_type_change.js
index 12035cc39a9..a0976b3ea44 100644
--- a/jstests/core/set_type_change.js
+++ b/jstests/core/set_type_change.js
@@ -12,7 +12,7 @@
 
 var coll = db.set_type_change;
 coll.drop();
-assert.commandWorked(coll.ensureIndex({a: 1}));
+assert.commandWorked(coll.createIndex({a: 1}));
 
 assert.commandWorked(coll.insert({a: 2}));
 
diff --git a/jstests/core/show_record_id.js b/jstests/core/show_record_id.js
index d111858bc7d..0f2df332354 100644
--- a/jstests/core/show_record_id.js
+++ b/jstests/core/show_record_id.js
@@ -25,7 +25,7 @@ t.save({});
 checkResults(t.find().batchSize(2).showRecordId().toArray());
 
 // Check with a covered index.
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 checkResults(t.find({}, {_id: 0, a: 1}).hint({a: 1}).showRecordId().toArray());
 checkResults(t.find({}, {_id: 0, a: 1}).hint({a: 1}).showRecordId().toArray());
 
diff --git a/jstests/core/skip1.js b/jstests/core/skip1.js
index ae8f589d616..3b99e6b4cdd 100644
--- a/jstests/core/skip1.js
+++ b/jstests/core/skip1.js
@@ -6,7 +6,7 @@ var t = db.jstests_skip1;
 if (0) {  // SERVER-2845
     t.drop();
 
-    t.ensureIndex({a: 1});
+    t.createIndex({a: 1});
     t.save({a: 5});
     t.save({a: 5});
     t.save({a: 5});
diff --git a/jstests/core/sort1.js b/jstests/core/sort1.js
index 39c8d3d333d..2a11771fd16 100644
--- a/jstests/core/sort1.js
+++ b/jstests/core/sort1.js
@@ -22,7 +22,7 @@ for (var pass = 0; pass < 2; pass++) {
     assert(coll.find().sort({x: -1})[1].x == 3);
     assert.eq(coll.find().sort({x: -1}).skip(0)[0].x, 5);
     assert.eq(coll.find().sort({x: -1}).skip(1)[0].x, 3);
-    coll.ensureIndex({x: 1});
+    coll.createIndex({x: 1});
 }
 
 assert(coll.validate().valid);
@@ -38,7 +38,7 @@ for (var pass = 0; pass < 2; pass++) {
     assert.eq("a", coll.find().sort({'x': 1}).next().x, "c.2");
     assert.eq("zed", coll.find().sort({'x': -1}).limit(1).next().x, "c.3");
     assert.eq("zed", coll.find().sort({'x': -1}).next().x, "c.4");
-    coll.ensureIndex({x: 1});
+    coll.createIndex({x: 1});
 }
 
 assert(coll.validate().valid);
diff --git a/jstests/core/sort10.js b/jstests/core/sort10.js
index 167cf74bbfc..6819c76fa5b 100644
--- a/jstests/core/sort10.js
+++ b/jstests/core/sort10.js
@@ -11,7 +11,7 @@ function checkSorting1(opts) {
     var d = new Date(-50);
     for (var pass = 0; pass < 2; pass++) {
         assert(t.find().sort({x: 1})[0].x.valueOf() == d.valueOf());
-        t.ensureIndex({x: 1}, opts);
+        t.createIndex({x: 1}, opts);
         t.insert({x: new Date()});
     }
 }
@@ -42,10 +42,10 @@ reverseDates = dates.slice(0).reverse();
 
 checkSorting2(dates, 1);
 checkSorting2(reverseDates, -1);
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 checkSorting2(dates, 1);
 checkSorting2(reverseDates, -1);
 t.dropIndexes();
-t.ensureIndex({x: -1});
+t.createIndex({x: -1});
 checkSorting2(dates, 1);
 checkSorting2(reverseDates, -1);
diff --git a/jstests/core/sort2.js b/jstests/core/sort2.js
index ca2d3dc80bf..c584dc48114 100644
--- a/jstests/core/sort2.js
+++ b/jstests/core/sort2.js
@@ -15,7 +15,7 @@ for (var pass = 0; pass < 2; pass++) {
     assert(res[0].y.a == 2);
     assert(res[1].y.a == 5);
     assert(res.length == 4);
-    t.ensureIndex({"y.a": 1});
+    t.createIndex({"y.a": 1});
 }
 assert(t.validate().valid);
 
@@ -31,5 +31,5 @@ for (var pass = 0; pass < 2; pass++) {
     for (var i = 0; i < good.length; i++) {
         assert(good[i].toString() == res[i].x.toString());
     }
-    t.ensureIndex({x: 1});
+    t.createIndex({x: 1});
 }
diff --git a/jstests/core/sort4.js b/jstests/core/sort4.js
index 0afe2cebe80..e74df1f4bd6 100644
--- a/jstests/core/sort4.js
+++ b/jstests/core/sort4.js
@@ -36,10 +36,10 @@ nice({name: 1, prename: 1}, "A,AB,AC,BB,BD", "e1");
 assert.commandWorked(coll.insert({name: 'C'}));
 nice({name: 1, prename: 1}, "A,AB,AC,BB,BD,C", "e2");  // SERVER-282
 
-assert.commandWorked(coll.ensureIndex({name: 1, prename: 1}));
+assert.commandWorked(coll.createIndex({name: 1, prename: 1}));
 nice({name: 1, prename: 1}, "A,AB,AC,BB,BD,C", "e2ia");  // SERVER-282
 
 assert.commandWorked(coll.dropIndexes());
-assert.commandWorked(coll.ensureIndex({name: 1}));
+assert.commandWorked(coll.createIndex({name: 1}));
 nice({name: 1, prename: 1}, "A,AB,AC,BB,BD,C", "e2ib");  // SERVER-282
 }());
diff --git a/jstests/core/sort5.js b/jstests/core/sort5.js
index 2f604225d7a..be40802ade4 100644
--- a/jstests/core/sort5.js
+++ b/jstests/core/sort5.js
@@ -16,7 +16,7 @@ assert.eq([4, 2, 3, 1],
               return z.x;
           }),
           "A no index");
-t.ensureIndex({"y.b": 1, "y.a": -1});
+t.createIndex({"y.b": 1, "y.a": -1});
 assert.eq([4, 2, 3, 1],
           t.find().sort({"y.b": 1, "y.a": -1}).map(function(z) {
               return z.x;
@@ -31,7 +31,7 @@ assert.eq([4, 2, 3, 1],
               return z.x;
           }),
           "B no index");
-t.ensureIndex({"y.b": 1, "_id": -1});
+t.createIndex({"y.b": 1, "_id": -1});
 assert.eq([4, 2, 3, 1],
           t.find().sort({"y.b": 1, _id: -1}).map(function(z) {
               return z.x;
diff --git a/jstests/core/sort6.js b/jstests/core/sort6.js
index 2373969f7f6..f2658bbcbad 100644
--- a/jstests/core/sort6.js
+++ b/jstests/core/sort6.js
@@ -16,7 +16,7 @@ t.insert({_id: 3, c: 2});
 assert.eq([3, 2, 1], get(-1), "A1");  // SERVER-635
 assert.eq([1, 2, 3], get(1), "A2");
 
-t.ensureIndex({c: 1});
+t.createIndex({c: 1});
 
 assert.eq([3, 2, 1], get(-1), "B1");
 assert.eq([1, 2, 3], get(1), "B2");
@@ -31,7 +31,7 @@ t.insert({_id: 3, c: 2});
 assert.eq([3, 2, 1], get(-1), "C1");  // SERVER-635
 assert.eq([1, 2, 3], get(1), "C2");
 
-t.ensureIndex({c: 1});
+t.createIndex({c: 1});
 
 assert.eq([3, 2, 1], get(-1), "D1");
 assert.eq([1, 2, 3], get(1), "X2");
diff --git a/jstests/core/sort8.js b/jstests/core/sort8.js
index 75d393445a7..65dc2c10fc2 100644
--- a/jstests/core/sort8.js
+++ b/jstests/core/sort8.js
@@ -10,7 +10,7 @@ t.save({a: [1, 10]});
 t.save({a: 5});
 unindexedForward = t.find().sort({a: 1}).toArray();
 unindexedReverse = t.find().sort({a: -1}).toArray();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 indexedForward = t.find().sort({a: 1}).hint({a: 1}).toArray();
 indexedReverse = t.find().sort({a: -1}).hint({a: 1}).toArray();
 
@@ -25,7 +25,7 @@ assert.eq([1, 10], unindexedReverse[0].a);
 t.dropIndexes();
 unindexedForward = t.find({a: {$gte: 5}}).sort({a: 1}).toArray();
 unindexedReverse = t.find({a: {$lte: 5}}).sort({a: -1}).toArray();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 indexedForward = t.find({a: {$gte: 5}}).sort({a: 1}).hint({a: 1}).toArray();
 indexedReverse = t.find({a: {$lte: 5}}).sort({a: -1}).hint({a: 1}).toArray();
 
diff --git a/jstests/core/sort_numeric.js b/jstests/core/sort_numeric.js
index df4e914b87b..5ff3e71a066 100644
--- a/jstests/core/sort_numeric.js
+++ b/jstests/core/sort_numeric.js
@@ -27,7 +27,7 @@ for (var pass = 0; pass < 2; pass++) {
     assert(t.find({a: 3.0}).count() == 1);
     assert(t.find({a: 3.0}).length() == 1);
 
-    t.ensureIndex({a: 1});
+    t.createIndex({a: 1});
 }
 
 assert(t.validate().valid);
diff --git a/jstests/core/sortb.js b/jstests/core/sortb.js
index 34fb94951e9..7f24592e84a 100644
--- a/jstests/core/sortb.js
+++ b/jstests/core/sortb.js
@@ -8,7 +8,7 @@ load("jstests/libs/fixture_helpers.js");  // For FixtureHelpers.
 const t = db.jstests_sortb;
 t.drop();
 
-t.ensureIndex({b: 1});
+t.createIndex({b: 1});
 
 let i;
 for (i = 0; i < 100; ++i) {
diff --git a/jstests/core/sortd.js b/jstests/core/sortd.js
index 87c0453cd7a..e18671005e4 100644
--- a/jstests/core/sortd.js
+++ b/jstests/core/sortd.js
@@ -21,7 +21,7 @@ t.drop();
 
 t.save({a: [1, 2, 3, 4, 5]});
 t.save({a: 10});
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 assert.eq(2, t.find({a: {$gt: 0}}).sort({a: 1}).itcount());
 assert.eq(2, t.find({a: {$gt: 0}, b: null}).sort({a: 1}).itcount());
@@ -38,7 +38,7 @@ for (i = 2; i <= 9; ++i) {
 for (i = 0; i < 30; ++i) {
     t.save({a: 100});
 }
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 checkNumSorted(10, t.find({a: {$gte: 0, $lte: 10}}).sort({a: 1}));
 checkNumSorted(10, t.find({a: {$gte: 0, $lte: 10}, b: null}).sort({a: 1}));
@@ -56,7 +56,7 @@ for (i = 2; i <= 199; ++i) {
 for (i = 0; i < 30; ++i) {
     t.save({a: 2000});
 }
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 checkNumSorted(200, t.find({a: {$gte: 0, $lte: 200}}).sort({a: 1}));
 checkNumSorted(200, t.find({a: {$gte: 0, $lte: 200}, b: null}).sort({a: 1}));
@@ -69,6 +69,6 @@ t.drop();
 for (i = 399; i >= 0; --i) {
     t.save({a: i});
 }
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 checkNumSorted(400, t.find({a: {$gte: 0, $lte: 400}, b: null}).batchSize(50).sort({a: 1}));
diff --git a/jstests/core/sortf.js b/jstests/core/sortf.js
index 6f34d80a59d..adb54f38b9c 100644
--- a/jstests/core/sortf.js
+++ b/jstests/core/sortf.js
@@ -9,8 +9,8 @@
 t = db.jstests_sortf;
 t.drop();
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 for (i = 0; i < 100; ++i) {
     t.save({a: 0, b: 0});
diff --git a/jstests/core/sortg.js b/jstests/core/sortg.js
index 64edbce53d0..bdf44f4db7b 100644
--- a/jstests/core/sortg.js
+++ b/jstests/core/sortg.js
@@ -47,9 +47,9 @@ noMemoryException({$natural: 1});
 
 assert.eq(1, t.getIndexes().length);
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
-t.ensureIndex({c: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
+t.createIndex({c: 1});
 
 assert.eq(4, t.getIndexes().length);
 
diff --git a/jstests/core/sorth.js b/jstests/core/sorth.js
index 4b5aa02c281..41563caa205 100644
--- a/jstests/core/sorth.js
+++ b/jstests/core/sorth.js
@@ -84,7 +84,7 @@ function reset(sort, index) {
     t.save({a: 2, b: 0});
     t.save({a: 2, b: 3});
     t.save({a: 2, b: 5});
-    t.ensureIndex(index);
+    t.createIndex(index);
     _sort = sort;
     _hint = index;
 }
diff --git a/jstests/core/sorti.js b/jstests/core/sorti.js
index b6518818683..e30739b4867 100644
--- a/jstests/core/sorti.js
+++ b/jstests/core/sorti.js
@@ -20,6 +20,6 @@ function checkBOrder(query) {
 
 checkBOrder(t.find().sort({a: 1}));
 checkBOrder(t.find({}, {_id: 0, b: 1}).sort({a: 1}));
-t.ensureIndex({b: 1});
+t.createIndex({b: 1});
 checkBOrder(t.find({}, {_id: 0, b: 1}).sort({a: 1}));
 checkBOrder(t.find({}, {_id: 0, b: 1}).sort({a: 1}).hint({b: 1}));
diff --git a/jstests/core/sortj.js b/jstests/core/sortj.js
index 58125c2c00c..a4e8dd599d4 100644
--- a/jstests/core/sortj.js
+++ b/jstests/core/sortj.js
@@ -11,7 +11,7 @@ load("jstests/libs/fixture_helpers.js");  // For FixtureHelpers.
 const t = db.jstests_sortj;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 const numShards = FixtureHelpers.numberOfShardsForCollection(t);
 
diff --git a/jstests/core/sortk.js b/jstests/core/sortk.js
index e207c8f1f78..f1b055c2bcc 100644
--- a/jstests/core/sortk.js
+++ b/jstests/core/sortk.js
@@ -23,7 +23,7 @@ function resetCollection() {
 }
 
 resetCollection();
-t.ensureIndex({a: 1, b: 1});
+t.createIndex({a: 1, b: 1});
 
 function simpleQuery(extraFields, sort, hint) {
     query = {a: {$in: [1, 2]}};
@@ -93,7 +93,7 @@ assert.eq(3, simpleQueryWithLimit(-3).itcount());
 
 // The index ordering is reversed.
 resetCollection();
-t.ensureIndex({a: 1, b: -1});
+t.createIndex({a: 1, b: -1});
 
 // The sort order is consistent with the index order.
 assert.eq(5, simpleQuery({}, {b: -1}, {a: 1, b: -1}).limit(-1)[0].b);
@@ -103,7 +103,7 @@ assert.eq(0, simpleQuery({}, {b: 1}, {a: 1, b: -1}).limit(-1)[0].b);
 
 // An equality constraint precedes the $in constraint.
 t.drop();
-t.ensureIndex({a: 1, b: 1, c: 1});
+t.createIndex({a: 1, b: 1, c: 1});
 t.save({a: 0, b: 0, c: -1});
 t.save({a: 0, b: 2, c: 1});
 t.save({a: 1, b: 1, c: 1});
diff --git a/jstests/core/splitvector.js b/jstests/core/splitvector.js
index da117c7d3ef..73903a45bb9 100644
--- a/jstests/core/splitvector.js
+++ b/jstests/core/splitvector.js
@@ -111,7 +111,7 @@ assert.eq(
 // -------------------------
 // Case 3: empty collection
 
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 assert.eq(
     [],
     db.runCommand({splitVector: "test.jstests_splitvector", keyPattern: {x: 1}, maxChunkSize: 1})
@@ -122,7 +122,7 @@ assert.eq(
 // Case 4: uniform collection
 
 resetCollection();
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 
 var case4 = function() {
     // Get baseline document size
@@ -156,7 +156,7 @@ case4();
 // Case 5: limit number of split points
 
 resetCollection();
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 
 var case5 = function() {
     // Fill collection and get split vector for 1MB maxChunkSize
@@ -180,7 +180,7 @@ case5();
 // Case 6: limit number of objects in a chunk
 
 resetCollection();
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 
 var case6 = function() {
     // Fill collection and get split vector for 1MB maxChunkSize
@@ -205,7 +205,7 @@ case6();
 // [1111111111111111,2,3)
 
 resetCollection();
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 
 var case7 = function() {
     // Fill collection and get split vector for 1MB maxChunkSize
@@ -227,7 +227,7 @@ case7();
 // [1, 22222222222222, 3)
 
 resetCollection();
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 
 var case8 = function() {
     bulkInsertDocsFixedX(f, 9, filler, 1);
@@ -251,7 +251,7 @@ case8();
 //
 
 resetCollection();
-f.ensureIndex({x: 1});
+f.createIndex({x: 1});
 
 var case9 = function() {
     f.save({x: 1});
@@ -286,51 +286,51 @@ case9();
 //
 
 resetCollection();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 case4();
 
 resetCollection();
-f.ensureIndex({x: 1, y: -1, z: 1});
+f.createIndex({x: 1, y: -1, z: 1});
 case4();
 
 resetCollection();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 case5();
 
 resetCollection();
-f.ensureIndex({x: 1, y: -1, z: 1});
+f.createIndex({x: 1, y: -1, z: 1});
 case5();
 
 resetCollection();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 case6();
 
 resetCollection();
-f.ensureIndex({x: 1, y: -1, z: 1});
+f.createIndex({x: 1, y: -1, z: 1});
 case6();
 
 resetCollection();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 case7();
 
 resetCollection();
-f.ensureIndex({x: 1, y: -1, z: 1});
+f.createIndex({x: 1, y: -1, z: 1});
 case7();
 
 resetCollection();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 case8();
 
 resetCollection();
-f.ensureIndex({x: 1, y: -1, z: 1});
+f.createIndex({x: 1, y: -1, z: 1});
 case8();
 
 resetCollection();
-f.ensureIndex({x: 1, y: 1});
+f.createIndex({x: 1, y: 1});
 case9();
 
 resetCollection();
-f.ensureIndex({x: 1, y: -1, z: 1});
+f.createIndex({x: 1, y: -1, z: 1});
 case9();
 
 print("PASSED");
diff --git a/jstests/core/stages_and_hash.js b/jstests/core/stages_and_hash.js
index aa91f27e542..e5260c6c1b1 100644
--- a/jstests/core/stages_and_hash.js
+++ b/jstests/core/stages_and_hash.js
@@ -13,9 +13,9 @@ for (var i = 0; i < N; ++i) {
     t.insert({foo: i, bar: N - i, baz: i});
 }
 
-t.ensureIndex({foo: 1});
-t.ensureIndex({bar: 1});
-t.ensureIndex({baz: 1});
+t.createIndex({foo: 1});
+t.createIndex({bar: 1});
+t.createIndex({baz: 1});
 
 // Scan foo <= 20
 ixscan1 = {
diff --git a/jstests/core/stages_and_sorted.js b/jstests/core/stages_and_sorted.js
index 97387d84064..aa4a2fa08c1 100644
--- a/jstests/core/stages_and_sorted.js
+++ b/jstests/core/stages_and_sorted.js
@@ -23,9 +23,9 @@ for (var i = 0; i < N; ++i) {
     t.insert({baz: 12});
 }
 
-t.ensureIndex({foo: 1});
-t.ensureIndex({bar: 1});
-t.ensureIndex({baz: 1});
+t.createIndex({foo: 1});
+t.createIndex({bar: 1});
+t.createIndex({baz: 1});
 
 // Scan foo == 1
 ixscan1 = {
diff --git a/jstests/core/stages_fetch.js b/jstests/core/stages_fetch.js
index 48d761e53e7..032cc930cf8 100644
--- a/jstests/core/stages_fetch.js
+++ b/jstests/core/stages_fetch.js
@@ -13,7 +13,7 @@ for (var i = 0; i < N; ++i) {
     t.insert({foo: i, bar: N - i, baz: i});
 }
 
-t.ensureIndex({foo: 1});
+t.createIndex({foo: 1});
 
 // 20 <= foo <= 30
 // bar == 25 (not covered, should error.)
diff --git a/jstests/core/stages_ixscan.js b/jstests/core/stages_ixscan.js
index 78e22e997c4..86184206e33 100644
--- a/jstests/core/stages_ixscan.js
+++ b/jstests/core/stages_ixscan.js
@@ -13,8 +13,8 @@ for (var i = 0; i < N; ++i) {
     t.insert({foo: i, bar: N - i, baz: i});
 }
 
-t.ensureIndex({foo: 1});
-t.ensureIndex({foo: 1, baz: 1});
+t.createIndex({foo: 1});
+t.createIndex({foo: 1, baz: 1});
 
 // Test that stageDebug fails if neither the keyPattern nor the index name are present.
 assert.commandFailed(db.runCommand({
diff --git a/jstests/core/stages_limit_skip.js b/jstests/core/stages_limit_skip.js
index b2621623260..00ba7aae4f0 100644
--- a/jstests/core/stages_limit_skip.js
+++ b/jstests/core/stages_limit_skip.js
@@ -13,7 +13,7 @@ for (var i = 0; i < N; ++i) {
     t.insert({foo: i, bar: N - i, baz: i});
 }
 
-t.ensureIndex({foo: 1});
+t.createIndex({foo: 1});
 
 // foo <= 20, decreasing
 // Limit of 5 results.
diff --git a/jstests/core/stages_mergesort.js b/jstests/core/stages_mergesort.js
index c4c4125c1f3..6679da3d5a5 100644
--- a/jstests/core/stages_mergesort.js
+++ b/jstests/core/stages_mergesort.js
@@ -14,8 +14,8 @@ for (var i = 0; i < N; ++i) {
     t.insert({baz: 1, bar: i});
 }
 
-t.ensureIndex({foo: 1, bar: 1});
-t.ensureIndex({baz: 1, bar: 1});
+t.createIndex({foo: 1, bar: 1});
+t.createIndex({baz: 1, bar: 1});
 
 // foo == 1
 // We would (internally) use "": MinKey and "": MaxKey for the bar index bounds.
diff --git a/jstests/core/stages_or.js b/jstests/core/stages_or.js
index 0fd78bdfc5c..d255404a21c 100644
--- a/jstests/core/stages_or.js
+++ b/jstests/core/stages_or.js
@@ -13,9 +13,9 @@ for (var i = 0; i < N; ++i) {
     t.insert({foo: i, bar: N - i, baz: i});
 }
 
-t.ensureIndex({foo: 1});
-t.ensureIndex({bar: 1});
-t.ensureIndex({baz: 1});
+t.createIndex({foo: 1});
+t.createIndex({bar: 1});
+t.createIndex({baz: 1});
 
 // baz >= 40
 ixscan1 = {
diff --git a/jstests/core/stages_sort.js b/jstests/core/stages_sort.js
index 46b81662100..60f22c680eb 100644
--- a/jstests/core/stages_sort.js
+++ b/jstests/core/stages_sort.js
@@ -8,7 +8,7 @@ if (false) {
         t.insert({foo: i, bar: N - i});
     }
 
-    t.ensureIndex({foo: 1});
+    t.createIndex({foo: 1});
 
     // Foo <= 20, descending.
     ixscan1 = {
diff --git a/jstests/core/stages_text.js b/jstests/core/stages_text.js
index 50182b04bb4..4b5379a0e4c 100644
--- a/jstests/core/stages_text.js
+++ b/jstests/core/stages_text.js
@@ -11,7 +11,7 @@ var collname = "stages_text";
 
 t.save({x: "az b x"});
 
-t.ensureIndex({x: "text"});
+t.createIndex({x: "text"});
 
 // We expect to retrieve 'b'
 res = db.runCommand({stageDebug: {collection: collname, plan: {text: {args: {search: "b"}}}}});
diff --git a/jstests/core/type1.js b/jstests/core/type1.js
index aae040dee90..8066de2a5c4 100644
--- a/jstests/core/type1.js
+++ b/jstests/core/type1.js
@@ -13,7 +13,7 @@ assert.eq(1, t.find({x: {$type: 1}}).count(), "A2");
 assert.eq(3, t.find({x: {$type: 2}}).count(), "A3");
 assert.eq(0, t.find({x: {$type: 3}}).count(), "A4");
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 assert.eq(4, t.find().count(), "B1");
 assert.eq(1, t.find({x: {$type: 1}}).count(), "B2");
diff --git a/jstests/core/type2.js b/jstests/core/type2.js
index 9c6baa37b94..d93d313d60f 100644
--- a/jstests/core/type2.js
+++ b/jstests/core/type2.js
@@ -15,5 +15,5 @@ function test() {
 }
 
 test();
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 test();
 \ No newline at end of file
diff --git a/jstests/core/type3.js b/jstests/core/type3.js
index 6c2c71e2b0c..1b57e9bb989 100644
--- a/jstests/core/type3.js
+++ b/jstests/core/type3.js
@@ -8,7 +8,7 @@
 t = db.jstests_type3;
 t.drop();
 
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 
 // Type Object
 t.save({a: {'': ''}});
diff --git a/jstests/core/uniqueness.js b/jstests/core/uniqueness.js
index d138f59d0ae..af4dfb1507f 100644
--- a/jstests/core/uniqueness.js
+++ b/jstests/core/uniqueness.js
@@ -40,7 +40,7 @@ db.jstests_uniqueness2.drop();
 db.jstests_uniqueness2.insert({a: 3});
 db.jstests_uniqueness2.insert({a: 3});
 assert.eq(2, db.jstests_uniqueness2.count());
-res = db.jstests_uniqueness2.ensureIndex({a: 1}, true);
+res = db.jstests_uniqueness2.createIndex({a: 1}, true);
 assert.commandFailed(res);
 assert(res.errmsg.match(/E11000/));
 
@@ -49,7 +49,7 @@ db.jstests_uniqueness2.drop();
 db.jstests_uniqueness2.insert({a: 3});
 db.jstests_uniqueness2.insert({a: 3});
 assert.eq(2, db.jstests_uniqueness2.count());
-res = db.jstests_uniqueness2.ensureIndex({a: 1}, {unique: true, background: true});
+res = db.jstests_uniqueness2.createIndex({a: 1}, {unique: true, background: true});
 assert.commandFailed(res);
 assert(res.errmsg.match(/E11000/));
 
diff --git a/jstests/core/update2.js b/jstests/core/update2.js
index 558e3c7f558..080875b50bd 100644
--- a/jstests/core/update2.js
+++ b/jstests/core/update2.js
@@ -12,7 +12,7 @@ assert.eq(6, f.findOne().a);
 
 f.drop();
 f.save({a: 4});
-f.ensureIndex({a: 1});
+f.createIndex({a: 1});
 f.update({a: 4}, {$inc: {a: 2}});
 assert.eq(6, f.findOne().a);
 
diff --git a/jstests/core/update5.js b/jstests/core/update5.js
index 7f41096889c..fafc0d72ce0 100644
--- a/jstests/core/update5.js
+++ b/jstests/core/update5.js
@@ -26,7 +26,7 @@ function go(key) {
     var ik = {};
     for (k in key)
         ik[k] = 1;
-    t.ensureIndex(ik);
+    t.createIndex(ik);
 
     t.update(key, {$inc: {n: 1}}, true);
     check(4, "D");
diff --git a/jstests/core/update7.js b/jstests/core/update7.js
index cb15f211d63..30dd79951dc 100644
--- a/jstests/core/update7.js
+++ b/jstests/core/update7.js
@@ -49,8 +49,8 @@ assert.eq("3,6", s(), "B3");
 t.update({b: 3}, {$inc: {x: 1}}, false, true);
 assert.eq("3,6", s(), "B4");
 
-t.ensureIndex({a: 1});
-t.ensureIndex({b: 1});
+t.createIndex({a: 1});
+t.createIndex({b: 1});
 
 t.update({a: 1}, {$inc: {x: 1}}, false, true);
 assert.eq("4,7", s(), "B5");
@@ -91,7 +91,7 @@ t.drop();
 
 t.save({_id: 1, x: 1, a: [1, 2]});
 t.save({_id: 2, x: 5, a: [2, 3]});
-t.ensureIndex({a: 1});
+t.createIndex({a: 1});
 assert.eq("1,5", s(), "D1");
 
 t.update({a: 1}, {$inc: {x: 1}}, false, true);
@@ -134,7 +134,7 @@ t.save({x: 1});
 t.save({x: 2});
 t.save({x: 3});
 
-t.ensureIndex({x: 1});
+t.createIndex({x: 1});
 
 assert.eq("1,2,3", s(), "F1");
 t.update({x: {$gt: 0}}, {$inc: {x: 5}}, false, true);
diff --git a/jstests/core/update_arraymatch4.js b/jstests/core/update_arraymatch4.js
index bda7de512b8..3c087e53ca5 100644
--- a/jstests/core/update_arraymatch4.js
+++ b/jstests/core/update_arraymatch4.js
@@ -17,7 +17,7 @@ x.arr[0] = "A2";
 t.update({arr: "A1"}, {$set: {"arr.$": "A2"}});
 assert.eq(x, t.findOne(), "A2");
 
-t.ensureIndex({arr: 1});
+t.createIndex({arr: 1});
 x.arr[0] = "A3";
 t.update({arr: "A2"}, {$set: {"arr.$": "A3"}});
 assert.eq(x, t.findOne(), "A3");  // SERVER-1055
diff --git a/jstests/core/update_arraymatch5.js b/jstests/core/update_arraymatch5.js
index eeca2598d1c..4bddcb1ea26 100644
--- a/jstests/core/update_arraymatch5.js
+++ b/jstests/core/update_arraymatch5.js
@@ -7,7 +7,7 @@ t = db.update_arraymatch5;
 t.drop();
 
 t.insert({abc: {visible: true}, testarray: [{foobar_id: 316, visible: true, xxx: 1}]});
-t.ensureIndex({'abc.visible': 1, 'testarray.visible': 1, 'testarray.xxx': 1});
+t.createIndex({'abc.visible': 1, 'testarray.visible': 1, 'testarray.xxx': 1});
 assert(t.findOne({'abc.visible': true, testarray: {'$elemMatch': {visible: true, xxx: 1}}}), "A1");
 assert(t.findOne({testarray: {'$elemMatch': {visible: true, xxx: 1}}}), "A2");
 
diff --git a/jstests/core/update_arraymatch6.js b/jstests/core/update_arraymatch6.js
index ec318370561..1241753b866 100644
--- a/jstests/core/update_arraymatch6.js
+++ b/jstests/core/update_arraymatch6.js
@@ -16,5 +16,5 @@ function doTest() {
 
 doTest();
 t.drop();
-t.ensureIndex({'a.id': 1});
+t.createIndex({'a.id': 1});
 doTest();
 \ No newline at end of file
diff --git a/jstests/core/update_arraymatch7.js b/jstests/core/update_arraymatch7.js
index 4ee9ed26f7c..cded4ba56f4 100644
--- a/jstests/core/update_arraymatch7.js
+++ b/jstests/core/update_arraymatch7.js
@@ -20,5 +20,5 @@ function testPositionalInc() {
 testPositionalInc();
 
 // Now check with a non multikey index.
-t.ensureIndex({'a.b': 1});
+t.createIndex({'a.b': 1});
 testPositionalInc();
diff --git a/jstests/core/update_arraymatch8.js b/jstests/core/update_arraymatch8.js
index 6340acdb2ab..88b9d3374e8 100644
--- a/jstests/core/update_arraymatch8.js
+++ b/jstests/core/update_arraymatch8.js
@@ -12,7 +12,7 @@
 // array.$.name
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({'array': [{'name': 'old'}]});
 assert(t.findOne({'array.name': 'old'}));
 t.update({'array.name': 'old'}, {$set: {'array.$.name': 'new'}});
@@ -22,7 +22,7 @@ assert(!t.findOne({'array.name': 'old'}));
 // array.$   (failed in 2.2.2)
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({'array': [{'name': 'old'}]});
 assert(t.findOne({'array.name': 'old'}));
 t.update({'array.name': 'old'}, {$set: {'array.$': {'name': 'new'}}});
@@ -32,7 +32,7 @@ assert(!t.findOne({'array.name': 'old'}));
 // array.0.name
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({'array': [{'name': 'old'}]});
 assert(t.findOne({'array.name': 'old'}));
 t.update({'array.name': 'old'}, {$set: {'array.0.name': 'new'}});
@@ -42,7 +42,7 @@ assert(!t.findOne({'array.name': 'old'}));
 // array.0   (failed in 2.2.2)
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({'array': [{'name': 'old'}]});
 assert(t.findOne({'array.name': 'old'}));
 t.update({'array.name': 'old'}, {$set: {'array.0': {'name': 'new'}}});
@@ -56,7 +56,7 @@ arr = new Array();
 for (var i = 0; i < 20; i++) {
     arr.push({'name': 'old'});
 }
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({_id: 0, 'array': arr});
 assert(t.findOne({'array.name': 'old'}));
 t.update({_id: 0}, {$set: {'array.12.name': 'new'}});
@@ -71,7 +71,7 @@ arr = new Array();
 for (var i = 0; i < 20; i++) {
     arr.push({'name': 'old'});
 }
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({_id: 0, 'array': arr});
 assert(t.findOne({'array.name': 'old'}));
 t.update({_id: 0}, {$set: {'array.12': {'name': 'new'}}});
@@ -82,7 +82,7 @@ assert(t.findOne({'array.name': 'old'}));
 // array.$.123a.name
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.123a.name': 1});
+t.createIndex({'array.123a.name': 1});
 t.insert({'array': [{'123a': {'name': 'old'}}]});
 assert(t.findOne({'array.123a.name': 'old'}));
 t.update({'array.123a.name': 'old'}, {$set: {'array.$.123a.name': 'new'}});
@@ -92,7 +92,7 @@ assert(!t.findOne({'array.123a.name': 'old'}));
 // array.$.123a
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({'array': [{'123a': {'name': 'old'}}]});
 assert(t.findOne({'array.123a.name': 'old'}));
 t.update({'array.123a.name': 'old'}, {$set: {'array.$.123a': {'name': 'new'}}});
@@ -102,7 +102,7 @@ assert(!t.findOne({'array.123a.name': 'old'}));
 // array.0.123a.name
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.123a.name': 1});
+t.createIndex({'array.123a.name': 1});
 t.insert({'array': [{'123a': {'name': 'old'}}]});
 assert(t.findOne({'array.123a.name': 'old'}));
 t.update({'array.123a.name': 'old'}, {$set: {'array.0.123a.name': 'new'}});
@@ -112,7 +112,7 @@ assert(!t.findOne({'array.123a.name': 'old'}));
 // array.0.123a
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'array.name': 1});
+t.createIndex({'array.name': 1});
 t.insert({'array': [{'123a': {'name': 'old'}}]});
 assert(t.findOne({'array.123a.name': 'old'}));
 t.update({'array.123a.name': 'old'}, {$set: {'array.0.123a': {'name': 'new'}}});
@@ -122,7 +122,7 @@ assert(!t.findOne({'array.123a.name': 'old'}));
 // a.0.b
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'a.0.b': 1});
+t.createIndex({'a.0.b': 1});
 t.insert({'a': [[{b: 'old'}]]});
 assert(t.findOne({'a.0.0.b': 'old'}));
 assert(t.findOne({'a.0.b': 'old'}));
@@ -133,7 +133,7 @@ assert(!t.findOne({'a.0.b': 'old'}));
 // a.0.b.c
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'a.0.b.c': 1});
+t.createIndex({'a.0.b.c': 1});
 t.insert({'a': [{b: [{c: 'old'}]}]});
 assert(t.findOne({'a.0.b.0.c': 'old'}));
 assert(t.findOne({'a.b.0.c': 'old'}));
@@ -146,7 +146,7 @@ assert(!t.findOne({'a.0.b.c': 'old'}));
 // a.b.$ref
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'a.b.$ref': 1});
+t.createIndex({'a.b.$ref': 1});
 t.insert({'a': [{'b': {'$ref': 'old', '$id': 0}}]});
 assert(t.findOne({'a.b.$ref': 'old'}));
 assert(t.findOne({'a.0.b.$ref': 'old'}));
@@ -157,8 +157,8 @@ assert(!t.findOne({'a.b.$ref': 'old'}));
 // a.b and a-b
 t = db.jstests_update_arraymatch8;
 t.drop();
-t.ensureIndex({'a.b': 1});
-t.ensureIndex({'a-b': 1});
+t.createIndex({'a.b': 1});
+t.createIndex({'a-b': 1});
 t.insert({'a': {'b': 'old'}});
 assert(t.findOne({'a.b': 'old'}));
 t.update({}, {$set: {'a': {'b': 'new'}}});
diff --git a/jstests/core/update_multi3.js b/jstests/core/update_multi3.js
index 0077bfefead..c8a1fa3b11d 100644
--- a/jstests/core/update_multi3.js
+++ b/jstests/core/update_multi3.js
@@ -6,7 +6,7 @@ function test(useIndex) {
     t.drop();
 
     if (useIndex)
-        t.ensureIndex({k: 1});
+        t.createIndex({k: 1});
 
     for (i = 0; i < 10; i++) {
         t.save({_id: i, k: 'x', a: []});
diff --git a/jstests/core/update_multi4.js b/jstests/core/update_multi4.js
index d2030c5dc4b..38fd75358f0 100644
--- a/jstests/core/update_multi4.js
+++ b/jstests/core/update_multi4.js
@@ -7,7 +7,7 @@ for (i = 0; i < 1000; i++) {
     t.insert({_id: i, k: i % 12, v: "v" + i % 12});
 }
 
-t.ensureIndex({k: 1});
+t.createIndex({k: 1});
 
 assert.eq(84, t.count({k: 2, v: "v2"}), "A0");
 
diff --git a/jstests/core/update_setOnInsert.js b/jstests/core/update_setOnInsert.js
index 430f23ce6dd..9457c69f325 100644
--- a/jstests/core/update_setOnInsert.js
+++ b/jstests/core/update_setOnInsert.js
@@ -5,7 +5,7 @@ var res;
 function dotest(useIndex) {
     t.drop();
     if (useIndex) {
-        t.ensureIndex({a: 1});
+        t.createIndex({a: 1});
     }
 
     t.update({_id: 5}, {$inc: {x: 2}, $setOnInsert: {a: 3}}, true);
diff --git a/jstests/core/useindexonobjgtlt.js b/jstests/core/useindexonobjgtlt.js
index 4d2368f316f..7b393de7c2f 100644
--- a/jstests/core/useindexonobjgtlt.js
+++ b/jstests/core/useindexonobjgtlt.js
@@ -3,7 +3,7 @@
 t = db.factories;
 t.drop();
 t.insert({name: "xyz", metro: {city: "New York", state: "NY"}});
-t.ensureIndex({metro: 1});
+t.createIndex({metro: 1});
 
 assert(db.factories.find().count());
author	Rishab Joshi <rishab.joshi@mongodb.com>	2020-11-10 13:42:25 +0000
committer	Evergreen Agent <no-reply@evergreen.mongodb.com>	2020-11-12 10:38:50 +0000
commit	e69c967ff8b53634770438dfe9a5c7d13548351b (patch)
tree	cf8f6b10b2374f388d51213d172f28b4fd3d05e8 /jstests/core
parent	916c466afac10d34e61b6ca42a12e35d7c4828f1 (diff)
download	mongo-e69c967ff8b53634770438dfe9a5c7d13548351b.tar.gz