SERVER-36015 Remove references to system.namespaces and system.indexes

33 files changed, 80 insertions, 679 deletions

diff --git a/jstests/auth/basic_role_auth.js b/jstests/auth/basic_role_auth.js
index 81e1518152c..f21ef40d962 100644
--- a/jstests/auth/basic_role_auth.js
+++ b/jstests/auth/basic_role_auth.js
@@ -120,7 +120,12 @@ var testOps = function(db, allowedActions) {
     });
 
     checkErr(allowedActions.hasOwnProperty('index_r'), function() {
-        db.system.indexes.findOne();
+        var errorCodeUnauthorized = 13;
+        var res = db.runCommand({"listIndexes": "user"});
+
+        if (res.code == errorCodeUnauthorized) {
+            throw Error("unauthorized listIndexes")
+        }
     });
 
     checkErr(allowedActions.hasOwnProperty('index_w'), function() {
diff --git a/jstests/auth/clac_system_colls.js b/jstests/auth/clac_system_colls.js
index 0b2fd75d69f..d9a6912e0ea 100644
--- a/jstests/auth/clac_system_colls.js
+++ b/jstests/auth/clac_system_colls.js
@@ -10,14 +10,7 @@ function runTest(admindb) {
     admindb.createUser({user: "admin", pwd: "pwd", roles: ["userAdminAnyDatabase"]});
     assert.eq(1, admindb.auth("admin", "pwd"));
 
-    var sysCollections = [
-        "system.indexes",
-        "system.js",
-        "system.namespaces",
-        "system.profile",
-        "system.roles",
-        "system.users"
-    ];
+    var sysCollections = ["system.js", "system.profile", "system.roles", "system.users"];
     var sysPrivs = new Array();
     for (var i in sysCollections) {
         sysPrivs.push(
diff --git a/jstests/auth/indexSystemUsers.js b/jstests/auth/indexSystemUsers.js
index 10bcaf24965..8b9069b1afb 100644
--- a/jstests/auth/indexSystemUsers.js
+++ b/jstests/auth/indexSystemUsers.js
@@ -15,8 +15,6 @@ adminDB.auth('mallory', 'x');
 var res = adminDB.system.users.createIndex({haxx: 1}, {unique: true, dropDups: true});
 assert(!res.ok);
 assert.eq(13, res.code);  // unauthorized
-assert.writeError(adminDB.exploit.system.indexes.insert(
-    {ns: "admin.system.users", key: {haxx: 1.0}, name: "haxx_1", unique: true, dropDups: true}));
 // Make sure that no indexes were built.
 var collectionInfosCursor = adminDB.runCommand("listCollections", {
     filter: {
@@ -34,4 +32,4 @@ adminDB.logout();
 adminDB.auth('admin', 'x');
 // Make sure that no users were actually dropped
 assert.eq(3, adminDB.system.users.count());
-MongoRunner.stopMongod(conn, null, {user: 'admin', pwd: 'x'});
\ No newline at end of file
+MongoRunner.stopMongod(conn, null, {user: 'admin', pwd: 'x'});
diff --git a/jstests/auth/lib/commands_lib.js b/jstests/auth/lib/commands_lib.js
index c50fc1c9d99..b61ab47137a 100644
--- a/jstests/auth/lib/commands_lib.js
+++ b/jstests/auth/lib/commands_lib.js
@@ -4604,34 +4604,24 @@ var authCommandsLib = {
               db.x.drop();
               db.y.drop();
           },
-          testcases: [
-              {
-                runOnDb: firstDbName,
-                roles: {
-                    read: 1,
-                    readAnyDatabase: 1,
-                    readWrite: 1,
-                    readWriteAnyDatabase: 1,
-                    dbAdmin: 1,
-                    dbAdminAnyDatabase: 1,
-                    dbOwner: 1,
-                    backup: 1,
-                    restore: 1,
-                    root: 1,
-                    __system: 1
-                },
-                privileges:
-                    [{resource: {db: firstDbName, collection: ""}, actions: ["listCollections"]}]
+          testcases: [{
+              runOnDb: firstDbName,
+              roles: {
+                  read: 1,
+                  readAnyDatabase: 1,
+                  readWrite: 1,
+                  readWriteAnyDatabase: 1,
+                  dbAdmin: 1,
+                  dbAdminAnyDatabase: 1,
+                  dbOwner: 1,
+                  backup: 1,
+                  restore: 1,
+                  root: 1,
+                  __system: 1
               },
-              // Test legacy (pre 3.0) way of authorizing listCollections.
-              {
-                runOnDb: firstDbName,
-                privileges: [{
-                    resource: {db: firstDbName, collection: "system.namespaces"},
-                    actions: ["find"]
-                }]
-              }
-          ]
+              privileges:
+                  [{resource: {db: firstDbName, collection: ""}, actions: ["listCollections"]}]
+          }]
         },
         {
           testname: "listOwnCollections",
@@ -4668,14 +4658,6 @@ var authCommandsLib = {
                     __system: 1
                 },
               },
-              // Test legacy (pre 3.0) way of authorizing listCollections.
-              {
-                runOnDb: firstDbName,
-                privileges: [{
-                    resource: {db: firstDbName, collection: "system.namespaces"},
-                    actions: ["find"]
-                }]
-              },
               {
                 runOnDb: firstDbName,
                 privileges: [{resource: {db: firstDbName, collection: "x"}, actions: ["find"]}]
@@ -4716,33 +4698,23 @@ var authCommandsLib = {
           teardown: function(db) {
               db.x.drop();
           },
-          testcases: [
-              {
-                runOnDb: firstDbName,
-                roles: {
-                    read: 1,
-                    readAnyDatabase: 1,
-                    readWrite: 1,
-                    readWriteAnyDatabase: 1,
-                    dbAdmin: 1,
-                    dbAdminAnyDatabase: 1,
-                    dbOwner: 1,
-                    backup: 1,
-                    root: 1,
-                    __system: 1
-                },
-                privileges:
-                    [{resource: {db: firstDbName, collection: ""}, actions: ["listIndexes"]}]
+          testcases: [{
+              runOnDb: firstDbName,
+              roles: {
+                  read: 1,
+                  readAnyDatabase: 1,
+                  readWrite: 1,
+                  readWriteAnyDatabase: 1,
+                  dbAdmin: 1,
+                  dbAdminAnyDatabase: 1,
+                  dbOwner: 1,
+                  backup: 1,
+                  root: 1,
+                  __system: 1
               },
-              // Test legacy (pre 3.0) way of authorizing listIndexes.
-              {
-                runOnDb: firstDbName,
-                privileges: [{
-                    resource: {db: firstDbName, collection: "system.indexes"},
-                    actions: ["find"]
-                }]
-              }
-          ]
+              privileges:
+                  [{resource: {db: firstDbName, collection: ""}, actions: ["listIndexes"]}]
+          }]
         },
         {
           testname: "listIndexesWithUUID",
@@ -4759,25 +4731,14 @@ var authCommandsLib = {
           teardown: function(db) {
               db.x.drop();
           },
-          testcases: [
-              {
-                runOnDb: firstDbName,
-                roles: {backup: 1, root: 1, __system: 1},
-                privileges: [
-                    {resource: {db: firstDbName, collection: ""}, actions: ["listIndexes"]},
-                    {resource: {cluster: true}, actions: ["useUUID"]}
-                ]
-              },
-              // Test legacy (pre 3.0) way of authorizing listIndexes.
-              {
-                runOnDb: firstDbName,
-                privileges: [
-                    {resource: {db: firstDbName, collection: "system.indexes"}, actions: ["find"]},
-                    {resource: {cluster: true}, actions: ["useUUID"]}
-
-                ]
-              }
-          ]
+          testcases: [{
+              runOnDb: firstDbName,
+              roles: {backup: 1, root: 1, __system: 1},
+              privileges: [
+                  {resource: {db: firstDbName, collection: ""}, actions: ["listIndexes"]},
+                  {resource: {cluster: true}, actions: ["useUUID"]}
+              ]
+          }]
         },
 
         {
diff --git a/jstests/core/apply_ops1.js b/jstests/core/apply_ops1.js
index e71c33ad9b6..0b098bed8a0 100644
--- a/jstests/core/apply_ops1.js
+++ b/jstests/core/apply_ops1.js
@@ -212,82 +212,6 @@
     }),
                          "Excessively nested applyOps should be rejected");
 
-    // Missing 'o' field value in an operation of type 'i' on 'system.indexes' collection.
-    assert.commandFailedWithCode(
-        db.adminCommand({applyOps: [{op: 'i', ns: db.getName() + '.system.indexes'}]}),
-        ErrorCodes.NoSuchKey,
-        'applyOps should fail on system.indexes insert operation without "o" field');
-
-    // Non-object 'o' field value in an operation of type 'i' on 'system.indexes' collection.
-    assert.commandFailedWithCode(
-        db.adminCommand({applyOps: [{op: 'i', ns: db.getName() + '.system.indexes', o: 'bar'}]}),
-        ErrorCodes.TypeMismatch,
-        'applyOps should fail on system.indexes insert operation with non-object "o" field');
-
-    // Missing 'ns' field in index spec.
-    assert.commandFailedWithCode(
-        db.adminCommand({
-            applyOps: [{
-                op: 'i',
-                ns: db.getName() + '.system.indexes',
-                o: {
-                    key: {a: 1},
-                    name: 'a_1',
-                }
-            }]
-        }),
-        ErrorCodes.NoSuchKey,
-        'applyOps should fail on system.indexes insert operation with missing index namespace');
-
-    // Non-string 'ns' field in index spec.
-    assert.commandFailedWithCode(
-        db.adminCommand({
-            applyOps: [{
-                op: 'i',
-                ns: db.getName() + '.system.indexes',
-                o: {
-                    ns: 12345,
-                    key: {a: 1},
-                    name: 'a_1',
-                }
-            }]
-        }),
-        ErrorCodes.TypeMismatch,
-        'applyOps should fail on system.indexes insert operation with non-string index namespace');
-
-    // Invalid 'ns' field in index spec.
-    assert.commandFailedWithCode(
-        db.adminCommand({
-            applyOps: [{
-                op: 'i',
-                ns: db.getName() + '.system.indexes',
-                o: {
-                    ns: 'invalid_namespace',
-                    key: {a: 1},
-                    name: 'a_1',
-                }
-            }]
-        }),
-        ErrorCodes.InvalidNamespace,
-        'applyOps should fail on system.indexes insert operation with invalid index namespace');
-
-    // Inconsistent database name in index spec namespace.
-    assert.commandFailedWithCode(
-        db.adminCommand({
-            applyOps: [{
-                op: 'i',
-                ns: db.getName() + '.system.indexes',
-                o: {
-                    ns: 'baddbprefix' + t.getFullName(),
-                    key: {a: 1},
-                    name: 'a_1',
-                }
-            }]
-        }),
-        ErrorCodes.InvalidNamespace,
-        'applyOps should fail on system.indexes insert operation with index namespace containing ' +
-            'inconsistent database name');
-
     // Valid 'ns' field value in unknown operation type 'x'.
     assert.commandFailed(
         db.adminCommand({applyOps: [{op: 'x', ns: t.getFullName()}]}),
@@ -476,65 +400,6 @@
     assert.eq(true, res.results[1], "Valid update with transaction number failed");
     assert.eq(true, res.results[2], "Valid delete with transaction number failed");
 
-    // Foreground index build.
-    res = assert.commandWorked(db.adminCommand({
-        applyOps: [{
-            "op": "i",
-            "ns": db.getName() + ".system.indexes",
-            "o": {
-                ns: t.getFullName(),
-                key: {a: 1},
-                name: "a_1",
-            }
-        }]
-    }));
-    assert.eq(1, res.applied, "Incorrect number of operations applied");
-    assert.eq(true, res.results[0], "Foreground index creation failed");
-    var allIndexes = t.getIndexes();
-    var spec = GetIndexHelpers.findByName(allIndexes, "a_1");
-    assert.neq(null, spec, "Foreground index 'a_1' not found: " + tojson(allIndexes));
-    assert.eq(1, spec.v, "Expected v=1 index to be built since 'v' field was omitted");
-
-    // Background indexes are created in the foreground when processed by applyOps.
-    res = assert.commandWorked(db.adminCommand({
-        applyOps: [{
-            "op": "i",
-            "ns": db.getName() + ".system.indexes",
-            "o": {
-                ns: t.getFullName(),
-                key: {b: 1},
-                name: "b_1",
-                background: true,
-            }
-        }]
-    }));
-    assert.eq(1, res.applied, "Incorrect number of operations applied");
-    assert.eq(true, res.results[0], "Background index creation failed");
-    allIndexes = t.getIndexes();
-    spec = GetIndexHelpers.findByName(allIndexes, "b_1");
-    assert.neq(null, spec, "Background index 'b_1' not found: " + tojson(allIndexes));
-    assert.eq(1, spec.v, "Expected v=1 index to be built since 'v' field was omitted");
-
-    // Foreground v=2 index build.
-    res = assert.commandWorked(db.adminCommand({
-        applyOps: [{
-            "op": "i",
-            "ns": db.getName() + ".system.indexes",
-            "o": {
-                ns: t.getFullName(),
-                key: {c: 1},
-                name: "c_1",
-                v: 2,
-            }
-        }]
-    }));
-    assert.eq(1, res.applied, "Incorrect number of operations applied");
-    assert.eq(true, res.results[0], "Foreground v=2 index creation failed");
-    allIndexes = t.getIndexes();
-    spec = GetIndexHelpers.findByName(allIndexes, "c_1");
-    assert.neq(null, spec, "Foreground index 'c_1' not found: " + tojson(allIndexes));
-    assert.eq(2, spec.v, "Expected v=2 index to be built");
-
     // When applying a "u" (update) op, we default to 'UpdateNode' update semantics, and $set
     // operations add new fields in lexicographic order.
     res = assert.commandWorked(db.adminCommand({
diff --git a/jstests/core/apply_ops_index_collation.js b/jstests/core/apply_ops_index_collation.js
index 135cb37483f..d58d3659223 100644
--- a/jstests/core/apply_ops_index_collation.js
+++ b/jstests/core/apply_ops_index_collation.js
@@ -87,66 +87,4 @@
     assert.neq(null, spec, "Index 'b_1' not found: " + tojson(allIndexes));
     assert.eq(1, spec.v, tojson(spec));
     assert(!spec.hasOwnProperty("collation"), tojson(spec));
-
-    // An index created using an insert-style oplog entry with a non-simple collation does not
-    // inherit the collection default collation.
-    res = assert.commandWorked(db.adminCommand({
-        applyOps: [{
-            op: "i",
-            ns: db.system.indexes.getFullName(),
-            o: {
-                v: 2,
-                key: {c: 1},
-                name: "c_1_en",
-                ns: coll.getFullName(),
-                collation: {
-                    locale: "en_US",
-                    caseLevel: false,
-                    caseFirst: "off",
-                    strength: 3,
-                    numericOrdering: false,
-                    alternate: "non-ignorable",
-                    maxVariable: "punct",
-                    normalization: false,
-                    backwards: false,
-                    version: "57.1"
-                }
-            }
-        }]
-    }));
-    allIndexes = coll.getIndexes();
-    spec = GetIndexHelpers.findByName(allIndexes, "c_1_en");
-    assert.neq(null, spec, "Index 'c_1_en' not found: " + tojson(allIndexes));
-    assert.eq(2, spec.v, tojson(spec));
-    assert.eq("en_US", spec.collation.locale, tojson(spec));
-
-    // An index created using an insert-style oplog entry with a simple collation does not inherit
-    // the collection default collation.
-    res = assert.commandWorked(db.adminCommand({
-        applyOps: [{
-            op: "i",
-            ns: db.system.indexes.getFullName(),
-            o: {v: 2, key: {c: 1}, name: "c_1", ns: coll.getFullName()}
-        }]
-    }));
-    allIndexes = coll.getIndexes();
-    spec = GetIndexHelpers.findByName(allIndexes, "c_1");
-    assert.neq(null, spec, "Index 'c_1' not found: " + tojson(allIndexes));
-    assert.eq(2, spec.v, tojson(spec));
-    assert(!spec.hasOwnProperty("collation"), tojson(spec));
-
-    // A v=1 index created using an insert-style oplog entry does not inherit the collection default
-    // collation.
-    res = assert.commandWorked(db.adminCommand({
-        applyOps: [{
-            op: "i",
-            ns: db.system.indexes.getFullName(),
-            o: {v: 1, key: {d: 1}, name: "d_1", ns: coll.getFullName()}
-        }]
-    }));
-    allIndexes = coll.getIndexes();
-    spec = GetIndexHelpers.findByName(allIndexes, "d_1");
-    assert.neq(null, spec, "Index 'd_1' not found: " + tojson(allIndexes));
-    assert.eq(1, spec.v, tojson(spec));
-    assert(!spec.hasOwnProperty("collation"), tojson(spec));
 })();
diff --git a/jstests/core/batch_write_command_insert.js b/jstests/core/batch_write_command_insert.js
index d1e3fc8b600..5d0a85fa763 100644
--- a/jstests/core/batch_write_command_insert.js
+++ b/jstests/core/batch_write_command_insert.js
@@ -261,129 +261,6 @@ coll.find().forEach(function(doc) {
 });
 
 //
-//
-// Index insertion tests - currently supported via bulk write commands
-
-//
-// Successful index creation
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString(), key: {x: 1}, name: "x_1"}]
-};
-result = coll.runCommand(request);
-assert(result.ok, tojson(result));
-assert.eq(1, result.n);
-var allIndexes = coll.getIndexes();
-var spec = GetIndexHelpers.findByName(allIndexes, "x_1");
-assert.neq(null, spec, "Index with name 'x_1' not found: " + tojson(allIndexes));
-assert.lte(2, spec.v, tojson(spec));
-
-// Test that a v=1 index can be created by inserting into the system.indexes collection.
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString(), key: {x: 1}, name: "x_1", v: 1}]
-};
-result = coll.runCommand(request);
-assert(result.ok, tojson(result));
-assert.eq(1, result.n);
-allIndexes = coll.getIndexes();
-spec = GetIndexHelpers.findByName(allIndexes, "x_1");
-assert.neq(null, spec, "Index with name 'x_1' not found: " + tojson(allIndexes));
-assert.eq(1, spec.v, tojson(spec));
-
-//
-// Duplicate index insertion gives n = 0
-coll.drop();
-coll.ensureIndex({x: 1}, {unique: true});
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString(), key: {x: 1}, name: "x_1", unique: true}]
-};
-result = coll.runCommand(request);
-assert(result.ok, tojson(result));
-assert.eq(0, result.n, 'duplicate index insertion should give n = 0: ' + tojson(result));
-assert(!('writeErrors' in result));
-assert.eq(coll.getIndexes().length, 2);
-
-//
-// Invalid index insertion with mismatched collection db
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{ns: "invalid." + coll.getName(), key: {x: 1}, name: "x_1", unique: true}]
-};
-result = coll.runCommand(request);
-assert(!result.ok || (result.n == 0 && result.writeErrors.length == 1), tojson(result));
-assert.eq(coll.getIndexes().length, 0);
-
-//
-// Empty index insertion
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{}]
-};
-result = coll.runCommand(request);
-assert(!result.ok || (result.n == 0 && result.writeErrors.length == 1), tojson(result));
-assert.eq(coll.getIndexes().length, 0);
-
-//
-// Invalid index desc
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString()}]
-};
-result = coll.runCommand(request);
-assert(result.ok, tojson(result));
-assert.eq(0, result.n);
-assert.eq(0, result.writeErrors[0].index);
-assert.eq(coll.getIndexes().length, 0);
-
-//
-// Invalid index desc
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString(), key: {x: 1}}]
-};
-result = coll.runCommand(request);
-print(tojson(result));
-assert(result.ok, tojson(result));
-assert.eq(0, result.n);
-assert.eq(0, result.writeErrors[0].index);
-assert.eq(coll.getIndexes().length, 0);
-
-//
-// Invalid index desc
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString(), name: "x_1"}]
-};
-result = coll.runCommand(request);
-assert(result.ok, tojson(result));
-assert.eq(0, result.n);
-assert.eq(0, result.writeErrors[0].index);
-assert.eq(coll.getIndexes().length, 0);
-
-//
-// Cannot insert more than one index at a time through the batch writes
-coll.drop();
-request = {
-    insert: "system.indexes",
-    documents: [
-        {ns: coll.toString(), key: {x: 1}, name: "x_1"},
-        {ns: coll.toString(), key: {y: 1}, name: "y_1"}
-    ]
-};
-result = coll.runCommand(request);
-assert(!result.ok, tojson(result));
-assert.eq(coll.getIndexes().length, 0);
-
-//
 // Ensure we error out correctly in the middle of a batch
 coll.drop();
 coll.insert({_id: 50});  // Create a document to force a duplicate key exception.
@@ -398,21 +275,3 @@ try {
 } catch (err) {
     assert(coll.count() == 50, "Unexpected number inserted by bulk write: " + coll.count());
 }
-
-//
-// Background index creation
-// Note: due to SERVER-13304 this test is at the end of this file, and we don't drop
-// the collection afterwards.
-coll.drop();
-coll.insert({x: 1});
-request = {
-    insert: "system.indexes",
-    documents: [{ns: coll.toString(), key: {x: 1}, name: "x_1", background: true}]
-};
-result = coll.runCommand(request);
-assert(result.ok, tojson(result));
-assert.eq(1, result.n);
-allIndexes = coll.getIndexes();
-spec = GetIndexHelpers.findByName(allIndexes, "x_1");
-assert.neq(null, spec, "Index with name 'x_1' not found: " + tojson(allIndexes));
-assert.lte(2, spec.v, tojson(spec));
diff --git a/jstests/core/cannot_create_system_dot_indexes.js b/jstests/core/cannot_create_system_dot_indexes.js
deleted file mode 100644
index 50928d5a27d..00000000000
--- a/jstests/core/cannot_create_system_dot_indexes.js
+++ /dev/null
@@ -1,51 +0,0 @@
-// Tests that a user cannot create the 'system.indexes' collection.
-// @tags: [requires_non_retryable_commands]
-(function() {
-    "use strict";
-
-    // Cannot create system.indexes using the 'create' command.
-    assert.commandFailedWithCode(db.createCollection("system.indexes"),
-                                 ErrorCodes.InvalidNamespace);
-    assert.eq(
-        0, db.getCollectionInfos({name: "system.indexes"}).length, tojson(db.getCollectionInfos()));
-
-    // Cannot create system.indexes using the 'renameCollection' command.
-    db.coll.drop();
-    assert.commandWorked(db.coll.insert({}));
-    assert.commandFailed(db.coll.renameCollection("system.indexes"));
-    assert.eq(
-        0, db.getCollectionInfos({name: "system.indexes"}).length, tojson(db.getCollectionInfos()));
-
-    // Cannot create system.indexes using the 'createIndexes' command.
-    assert.commandFailedWithCode(db.system.indexes.createIndex({a: 1}),
-                                 ErrorCodes.InvalidNamespace);
-    assert.eq(
-        0, db.getCollectionInfos({name: "system.indexes"}).length, tojson(db.getCollectionInfos()));
-
-    // Cannot create system.indexes using the 'insert' command.
-    assert.commandWorked(
-        db.system.indexes.insert({ns: "test.coll", v: 2, key: {a: 1}, name: "a_1"}));
-    assert.eq(
-        0, db.getCollectionInfos({name: "system.indexes"}).length, tojson(db.getCollectionInfos()));
-
-    // Cannot create system.indexes using the 'update' command with upsert=true.
-    assert.commandFailedWithCode(
-        db.system.indexes.update({ns: "test.coll", v: 2, key: {a: 1}, name: "a_1"},
-                                 {$set: {name: "a_1"}},
-                                 {upsert: true}),
-        ErrorCodes.InvalidNamespace);
-    assert.eq(
-        0, db.getCollectionInfos({name: "system.indexes"}).length, tojson(db.getCollectionInfos()));
-
-    // Cannot create system.indexes using the 'findAndModify' command with upsert=true.
-    let error = assert.throws(() => {
-        db.system.indexes.findAndModify({
-            query: {ns: "test.coll", v: 2, key: {a: 1}, name: "a_1"},
-            update: {$set: {name: "a_1"}},
-            upsert: true
-        });
-    });
-    assert.eq(error.code, ErrorCodes.InvalidNamespace);
-    assert.eq(
-        0, db.getCollectionInfos({name: "system.indexes"}).length, tojson(db.getCollectionInfos()));
-}());
diff --git a/jstests/core/indexOtherNamespace.js b/jstests/core/indexOtherNamespace.js
deleted file mode 100644
index 86589714a35..00000000000
--- a/jstests/core/indexOtherNamespace.js
+++ /dev/null
@@ -1,19 +0,0 @@
-// SERVER-8814: Test that only the system.indexes namespace can be used to build indexes.
-
-// Include helpers for analyzing explain output.
-load("jstests/libs/analyze_plan.js");
-
-var otherDB = db.getSiblingDB("indexOtherNS");
-otherDB.dropDatabase();
-
-otherDB.foo.insert({a: 1});
-assert.eq(1, otherDB.foo.getIndexes().length);
-assert(isCollscan(db, otherDB.foo.find({a: 1}).explain().queryPlanner.winningPlan));
-
-assert.writeError(
-    otherDB.randomNS.system.indexes.insert({ns: "indexOtherNS.foo", key: {a: 1}, name: "a_1"}));
-
-// Assert that index didn't actually get built
-assert.eq(1, otherDB.foo.getIndexes().length);
-assert(isCollscan(db, otherDB.foo.find({a: 1}).explain().queryPlanner.winningPlan));
-otherDB.dropDatabase();
diff --git a/jstests/core/indexapi.js b/jstests/core/indexapi.js
index 3153519501a..14cf634e556 100644
--- a/jstests/core/indexapi.js
+++ b/jstests/core/indexapi.js
@@ -43,7 +43,3 @@ idx = t.getIndexes();
 assert.eq(2, idx.length, "M1");
 assert.eq(key, idx[1].key, "M2");
 assert(idx[1].unique, "M3");
-// printjson( idx );
-
-// Test that attempting to create index in an invalid namespace fails.
-assert.writeError(db.system.indexes.insert({ns: "test", key: {x: 1}, name: "x"}));
diff --git a/jstests/core/indexes_on_indexes.js b/jstests/core/indexes_on_indexes.js
deleted file mode 100644
index b7c4b7edcb5..00000000000
--- a/jstests/core/indexes_on_indexes.js
+++ /dev/null
@@ -1,25 +0,0 @@
-// Ensure an index cannot be created on system.indexes
-(function() {
-    var t = db.getSiblingDB("indexes_on_indexes");
-    t.dropDatabase();
-    t.coll.insert({});
-
-    printjson(t.system.indexes.getIndexes());
-    assert.eq(t.system.indexes.getIndexes().length, 0);
-
-    print("trying via ensureIndex");
-    assert.commandFailed(t.system.indexes.ensureIndex({_id: 1}));
-    printjson(t.system.indexes.getIndexes());
-    assert.eq(t.system.indexes.getIndexes().length, 0);
-
-    print("trying via createIndex");
-    assert.commandFailed(t.system.indexes.createIndex({_id: 1}));
-    printjson(t.system.indexes.getIndexes());
-    assert.eq(t.system.indexes.getIndexes().length, 0);
-
-    print("trying via direct insertion");
-    assert.commandFailed(t.system.indexes.insert(
-        {v: 1, key: {_id: 1}, ns: "indexes_on_indexes.system.indexes", name: "wontwork"}));
-    printjson(t.system.indexes.getIndexes());
-    assert.eq(t.system.indexes.getIndexes().length, 0);
-}());
diff --git a/jstests/core/list_collections1.js b/jstests/core/list_collections1.js
index f23331b97ce..33377c2db97 100644
--- a/jstests/core/list_collections1.js
+++ b/jstests/core/list_collections1.js
@@ -58,20 +58,6 @@
     assert(!collObj.hasOwnProperty("idIndex"), tojson(collObj));
 
     //
-    // Test basic command output for system.indexes.
-    //
-
-    collObj = res.cursor.firstBatch.filter(function(c) {
-        return c.name === "system.indexes";
-    })[0];
-    if (collObj) {
-        assert.eq("object", typeof(collObj.options), tojson(collObj));
-        assert.eq("collection", collObj.type, tojson(collObj));
-        assert.eq(false, collObj.info.readOnly, tojson(collObj));
-        assert(!collObj.hasOwnProperty("idIndex"), tojson(collObj));
-    }
-
-    //
     // Test basic usage with DBCommandCursor.
     //
 
diff --git a/jstests/core/list_collections_filter.js b/jstests/core/list_collections_filter.js
index 76feeb9dd4b..ef162642bdf 100644
--- a/jstests/core/list_collections_filter.js
+++ b/jstests/core/list_collections_filter.js
@@ -24,16 +24,12 @@
         function stripToName(result) {
             return result.name;
         }
-        function isNotSystemIndexes(result) {
-            return result !== "system.indexes";
-        }
-        var cursorResultNames = cursor.toArray().map(stripToName).filter(isNotSystemIndexes);
+        var cursorResultNames = cursor.toArray().map(stripToName);
 
         assert.eq(cursorResultNames.sort(), expectedNames.sort());
 
         // Assert the shell helper returns the same list, but in sorted order.
-        var shellResultNames =
-            mydb.getCollectionInfos(filter).map(stripToName).filter(isNotSystemIndexes);
+        var shellResultNames = mydb.getCollectionInfos(filter).map(stripToName);
         assert.eq(shellResultNames, expectedNames.sort());
     }
 
diff --git a/jstests/core/list_collections_no_views.js b/jstests/core/list_collections_no_views.js
index 7ff19c9adce..b380f8c3db6 100644
--- a/jstests/core/list_collections_no_views.js
+++ b/jstests/core/list_collections_no_views.js
@@ -26,9 +26,6 @@
 
     assert.eq(allExpected,
               all.cursor.firstBatch
-                  .filter(function(c) {
-                      return c.name != "system.indexes";
-                  })
                   .map(function(c) {
                       return {name: c.name, type: c.type};
                   })
@@ -66,9 +63,6 @@
 
     assert.eq(collOnlyExpected,
               collOnly.cursor.firstBatch
-                  .filter(function(c) {
-                      return c.name != "system.indexes";
-                  })
                   .map(function(c) {
                       return {name: c.name, type: c.type};
                   })
@@ -93,9 +87,6 @@
 
     assert.eq(viewOnlyExpected,
               viewOnly.cursor.firstBatch
-                  .filter(function(c) {
-                      return c.name != "system.indexes";
-                  })
                   .map(function(c) {
                       return {name: c.name, type: c.type};
                   })
@@ -117,9 +108,6 @@
     let collOnlyInvalidView = mydb.runCommand(collOnlyCommand);
     assert.eq(collOnlyExpected,
               collOnlyInvalidView.cursor.firstBatch
-                  .filter(function(c) {
-                      return c.name != "system.indexes";
-                  })
                   .map(function(c) {
                       return {name: c.name, type: c.type};
                   })
diff --git a/jstests/core/list_indexes_invalidation.js b/jstests/core/list_indexes_invalidation.js
index 75a62da531a..38a70ce4005 100644
--- a/jstests/core/list_indexes_invalidation.js
+++ b/jstests/core/list_indexes_invalidation.js
@@ -2,7 +2,6 @@
 // on sharded collections.
 // @tags: [assumes_unsharded_collection, requires_non_retryable_commands, requires_fastcount]
 
-// SERVER-24963/SERVER-27930 Missing invalidation for system.indexes writes
 (function() {
     'use strict';
     let collName = 'system_indexes_invalidations';
diff --git a/jstests/core/list_namespaces_invalidation.js b/jstests/core/list_namespaces_invalidation.js
index da5d392b9f5..ebd5dd82542 100644
--- a/jstests/core/list_namespaces_invalidation.js
+++ b/jstests/core/list_namespaces_invalidation.js
@@ -1,6 +1,4 @@
 // @tags: [requires_non_retryable_commands, requires_fastcount]
-
-// SERVER-27996/SERVER-28022 Missing invalidation for system.namespaces writes
 (function() {
     'use strict';
     let dbInvalidName = 'system_namespaces_invalidations';
diff --git a/jstests/core/operation_latency_histogram.js b/jstests/core/operation_latency_histogram.js
index 1e971dc93eb..a8f0800b327 100644
--- a/jstests/core/operation_latency_histogram.js
+++ b/jstests/core/operation_latency_histogram.js
@@ -121,12 +121,7 @@
 
     // CreateIndex
     assert.commandWorked(testColl.createIndex({pt: "2dsphere"}));
-    // The createIndex shell helper is run as an insert when writeMode is not "commands".
-    if (testDB.getMongo().writeMode() === "commands") {
-        lastHistogram = assertHistogramDiffEq(testColl, lastHistogram, 0, 0, 1);
-    } else {
-        lastHistogram = assertHistogramDiffEq(testColl, lastHistogram, 0, 1, 0);
-    }
+    lastHistogram = assertHistogramDiffEq(testColl, lastHistogram, 0, 0, 1);
 
     // $geoNear aggregation stage
     assert.commandWorked(testDB.runCommand({
diff --git a/jstests/core/rename8.js b/jstests/core/rename8.js
index d0a2a2fea60..923b0a52cec 100644
--- a/jstests/core/rename8.js
+++ b/jstests/core/rename8.js
@@ -5,7 +5,6 @@
 var testdb =
     db.getSiblingDB("rename8");  // to avoid breaking other tests when we touch system.users
 var coll = testdb.rename8;
-var systemNamespaces = testdb.system.namespaces;
 var systemFoo = testdb.system.foo;
 var systemUsers = testdb.system.users;
 
@@ -18,11 +17,6 @@ coll.insert({});
 assert.commandFailed(coll.renameCollection(systemFoo.getName()));
 assert.commandFailed(systemFoo.renameCollection(coll.getName()));
 
-// same with system.namespaces, even though it does exist
-assert.commandFailed(coll.renameCollection(systemNamespaces.getName()));
-assert.commandFailed(coll.renameCollection(systemNamespaces.getName(), /*dropTarget*/ true));
-assert.commandFailed(systemNamespaces.renameCollection(coll.getName()));
-
 // system.users is whitelisted so these should work
 assert.commandWorked(coll.renameCollection(systemUsers.getName()));
 assert.commandWorked(systemUsers.renameCollection(coll.getName()));
diff --git a/jstests/core/top.js b/jstests/core/top.js
index 5919cdbe59d..eca4570472f 100644
--- a/jstests/core/top.js
+++ b/jstests/core/top.js
@@ -114,12 +114,7 @@
     // createIndex
     res = assert.commandWorked(testColl.createIndex({x: 1}));
     assertTopDiffEq(testColl, lastTop, "writeLock", 1);
-    // The createIndex shell helper is run as an insert when writeMode is not "commands".
-    if (testDB.getMongo().writeMode() === "commands") {
-        lastTop = assertTopDiffEq(testColl, lastTop, "commands", 1);
-    } else {
-        lastTop = assertTopDiffEq(testColl, lastTop, "insert", 1);
-    }
+    lastTop = assertTopDiffEq(testColl, lastTop, "commands", 1);
 
     // dropIndex
     res = assert.commandWorked(testColl.dropIndex({x: 1}));
diff --git a/jstests/core/txns/do_txn_atomicity.js b/jstests/core/txns/do_txn_atomicity.js
index f7077bd863e..59307a4641b 100644
--- a/jstests/core/txns/do_txn_atomicity.js
+++ b/jstests/core/txns/do_txn_atomicity.js
@@ -31,7 +31,7 @@
         ],
         txnNumber: NumberLong(txnNumber++)
     }),
-                                 16886);  // nsToCollectionSubstring: no .
+                                 ErrorCodes.InvalidNamespace);
     assert.eq(t.count({x: 1}), 0);
 
     // Operations on non-existent databases cannot be atomic.
diff --git a/jstests/core/views/views_creation.js b/jstests/core/views/views_creation.js
index 7fd2686dff5..68c896118a5 100644
--- a/jstests/core/views/views_creation.js
+++ b/jstests/core/views/views_creation.js
@@ -20,11 +20,6 @@
         ErrorCodes.InvalidNamespace,
         "Created an illegal view named 'system.views'");
 
-    assert.commandFailedWithCode(
-        viewsDB.runCommand({create: "system.indexes", viewOn: "collection"}),
-        ErrorCodes.InvalidNamespace,
-        "Created an illegal view named 'system.indexes'");
-
     // Collections that start with 'system.' that are not special to MongoDB fail with a different
     // error code.
     assert.commandFailedWithCode(viewsDB.runCommand({create: "system.foo", viewOn: "collection"}),
diff --git a/jstests/core/views/views_drop.js b/jstests/core/views/views_drop.js
index bc2a654415e..bf3498d85a6 100644
--- a/jstests/core/views/views_drop.js
+++ b/jstests/core/views/views_drop.js
@@ -27,7 +27,7 @@
     // Database should now be empty.
     let res = viewsDB.runCommand({listCollections: 1});
     assert.commandWorked(res);
-    assert.eq(res.cursor.firstBatch.filter((entry) => entry.name != "system.indexes"),
+    assert.eq(res.cursor.firstBatch,
               [],
               viewsDBName + " is not empty after deleting views and system.views");
 })();
diff --git a/jstests/multiVersion/index_bigkeys_secondary_downgrade_during_index_build_background.js b/jstests/multiVersion/index_bigkeys_secondary_downgrade_during_index_build_background.js
index 80f1a911b61..20836332643 100644
--- a/jstests/multiVersion/index_bigkeys_secondary_downgrade_during_index_build_background.js
+++ b/jstests/multiVersion/index_bigkeys_secondary_downgrade_during_index_build_background.js
@@ -45,7 +45,16 @@
 
     // Make sure index build starts on the secondary.
     assert.soon(() => {
-        let res = secondaryDB.currentOp({"ns": "test.system.indexes"});
+        // The currentOp entry for createIndexes looks like:
+        // {...,
+        //  "command": {"v": 2,
+        //              "key": {x: 1},
+        //              "name": "x_1",
+        //              "background": true,
+        //              "ns": "test.index_bigkeys_downgrade_during_index_build"},
+        //  ...
+        // }
+        let res = secondaryDB.currentOp({'command.name': "x_1"});
         return res['ok'] === 1 && res["inprog"].length > 0;
     });
 
diff --git a/jstests/noPassthrough/plan_cache_index_create.js b/jstests/noPassthrough/plan_cache_index_create.js
index 57f63a7a326..9213f59bc38 100644
--- a/jstests/noPassthrough/plan_cache_index_create.js
+++ b/jstests/noPassthrough/plan_cache_index_create.js
@@ -16,10 +16,7 @@
             "command.indexes.0.name": indexName
         };
         // TODO SERVER-34830: Add command name filter for secondaries once available.
-        const secondaryIndexBuildFilter = {
-            ns: dbName + ".system.indexes",
-            "command.name": indexName
-        };
+        const secondaryIndexBuildFilter = {"command.name": indexName};
         const curOp = testDB.getSiblingDB("admin").aggregate([
             {$currentOp: {}},
             {$match: {$or: [primaryIndexBuildFilter, secondaryIndexBuildFilter]}}
diff --git a/jstests/noPassthroughWithMongod/create_indexes_shell_helper.js b/jstests/noPassthroughWithMongod/create_indexes_shell_helper.js
index 6d9937139ae..8a36f7ee11e 100644
--- a/jstests/noPassthroughWithMongod/create_indexes_shell_helper.js
+++ b/jstests/noPassthroughWithMongod/create_indexes_shell_helper.js
@@ -9,11 +9,8 @@
         var commandsRan = [];
         var insertsRan = [];
         var mockMongo = {
-            forceWriteMode: function(mode) {
-                this._writeMode = mode;
-            },
             writeMode: function() {
-                return this._writeMode;
+                return "commands";
             },
             getSlaveOk: function() {
                 return true;
@@ -22,10 +19,6 @@
                 commandsRan.push({db: db, cmd: cmd, opts: opts});
                 return {ok: 1.0};
             },
-            insert: function(db, indexSpecs, opts) {
-                insertsRan.push({db: db, indexSpecs: indexSpecs, opts: opts});
-                return {ok: 1.0};
-            },
             getWriteConcern: function() {
                 return null;
             },
@@ -58,8 +51,6 @@
         db._mongo = mockMongo;
         db._session = new _DummyDriverSession(mockMongo);
 
-        mockMongo.forceWriteMode("commands");
-
         t.createIndexes([{x: 1}]);
         assert.eq(commandsRan.length, 1);
         assert(commandsRan[0].cmd.hasOwnProperty("createIndexes"));
@@ -79,19 +70,6 @@
         assert.eq(commandsRan.length, 1);
         assert(commandsRan[0].cmd.hasOwnProperty("createIndexes"));
         assert.eq(commandsRan[0].cmd["indexes"][0], {key: {a: 1}, name: "a_1"});
-
-        db.getMongo().forceWriteMode("compatibility");
-
-        commandsRan = [];
-        assert.eq(commandsRan.length, 0);
-        t.createIndex({b: 1});
-        assert.eq(insertsRan.length, 1);
-        assert.eq(insertsRan[0]["indexSpecs"]["ns"], "test.create_indexes_shell_helper");
-        assert.eq(insertsRan[0]["indexSpecs"]["key"], {b: 1});
-        assert.eq(insertsRan[0]["indexSpecs"]["name"], "b_1");
-        // getLastError is called in the course of the bulk insert
-        assert.eq(commandsRan.length, 1);
-        assert(commandsRan[0].cmd.hasOwnProperty("getlasterror"));
     } finally {
         db._mongo = mongo;
         db._session = new _DummyDriverSession(mongo);
diff --git a/jstests/replsets/apply_ops_create_indexes.js b/jstests/replsets/apply_ops_create_indexes.js
index 4fe813b5ed4..f400265afb0 100644
--- a/jstests/replsets/apply_ops_create_indexes.js
+++ b/jstests/replsets/apply_ops_create_indexes.js
@@ -1,6 +1,5 @@
 /* This test ensures that indexes created by running applyOps are successfully replicated (see
- * SERVER-31435). Both insertion into system.indexes and createIndexes style oplog entries are
- * passed to applyOps here.
+ * SERVER-31435).
  */
 (function() {
     "use strict";
@@ -70,33 +69,5 @@
         ensureIndexExists(secondaryTestDB, collName, cmdFormatIndexName, 2);
     }
 
-    // Create an index by inserting into system.indexes in applyOps.
-    let insertFormatIndexName = "b_1";
-    cmd = {
-        applyOps: [{
-            "op": "i",
-            "ns": dbName + ".system.indexes",
-            "o": {
-                ns: dbName + "." + collName,
-                key: {b: 1},
-                name: insertFormatIndexName,
-            }
-        }]
-    };
-    res = primaryTestDB.adminCommand(cmd);
-    assert.commandWorked(res, "could not run " + tojson(cmd));
-    rst.awaitReplication();
-    ensureIndexExists(primaryTestDB, collName, insertFormatIndexName, 3);
-
-    // Make sure the index was replicated to the secondaries.
-    secondaries = rst.getSecondaries();
-    for (let j = 0; j < secondaries.length; j++) {
-        let secondaryTestDB = secondaries[j].getDB(dbName);
-        ensureIndexExists(secondaryTestDB, collName, insertFormatIndexName, 3);
-    }
-
-    localDB = rst.getPrimary().getDB("local");
-    ensureOplogEntryExists(localDB, insertFormatIndexName);
-
     rst.stopSet();
 }());
diff --git a/jstests/replsets/oplog_format_create_indexes.js b/jstests/replsets/oplog_format_create_indexes.js
index ec779e28457..0697df44b07 100644
--- a/jstests/replsets/oplog_format_create_indexes.js
+++ b/jstests/replsets/oplog_format_create_indexes.js
@@ -26,13 +26,10 @@
             indexSpec,
             "Index with key pattern " + tojson(keyPattern) + " not found: " + tojson(allIndexes));
 
-        // Find either the old-style insert into system.indexes index creations, or new-style
-        // createIndexes command entries.
+        // Find the createIndexes command entries.
         const indexCreationOplogQuery = {
-            $or: [
-                {op: "i", ns: testDB.system.indexes.getFullName()},
-                {op: "c", ns: testDB.getName() + ".$cmd", "o.createIndexes": coll.getName()}
-            ]
+            op: "c",
+            ns: testDB.getName() + ".$cmd", "o.createIndexes": coll.getName()
         };
 
         const allOplogEntries = oplogColl.find(indexCreationOplogQuery).toArray();
diff --git a/jstests/replsets/rollback_views.js b/jstests/replsets/rollback_views.js
index a833ed82ecc..a7c89014de6 100644
--- a/jstests/replsets/rollback_views.js
+++ b/jstests/replsets/rollback_views.js
@@ -23,11 +23,10 @@ load("jstests/replsets/rslib.js");
     let checkedRunCommand = (db, cmd) =>
         ((res, msg) => (assert.commandWorked(res, msg), res))(db.runCommand(cmd), tojson(cmd));
 
-    // Like db.getCollectionNames, but allows a filter and works without system.namespaces.
+    // Like db.getCollectionNames, but allows a filter.
     let getCollectionNames = (db, filter) => checkedRunCommand(db, {listCollections: 1, filter})
                                                  .cursor.firstBatch.map((entry) => entry.name)
-                                                 .sort()
-                                                 .filter((name) => name != "system.indexes");
+                                                 .sort();
 
     // Function that checks that all array elements are equal, and returns the unique element.
     let checkEqual = (array, what) =>
diff --git a/jstests/sharding/clone_catalog_data.js b/jstests/sharding/clone_catalog_data.js
index f0cf4fac12d..dfb5863f69f 100644
--- a/jstests/sharding/clone_catalog_data.js
+++ b/jstests/sharding/clone_catalog_data.js
@@ -54,7 +54,7 @@
 
     var res = fromShard.getDB('test').runCommand({listCollections: 1});
     assert.commandWorked(res);
-    var collections = res.cursor.firstBatch.filter(coll => coll.name != 'system.indexes');
+    var collections = res.cursor.firstBatch;
 
     collections.sort(sortByName);
     var coll2uuid = collections[1].info.uuid;
@@ -67,7 +67,7 @@
     res = toShard.getDB('test').runCommand({listCollections: 1});
     assert.commandWorked(res);
 
-    collections = res.cursor.firstBatch.filter(coll => coll.name != 'system.indexes');
+    collections = res.cursor.firstBatch;
 
     // There should be 2 collections: coll1, coll2
     assert.eq(collections.length, 2);
diff --git a/jstests/sharding/move_primary_clone_test.js b/jstests/sharding/move_primary_clone_test.js
index 2ef19b044bf..6c30ff56b46 100644
--- a/jstests/sharding/move_primary_clone_test.js
+++ b/jstests/sharding/move_primary_clone_test.js
@@ -13,9 +13,7 @@
         var res = toShard.getDB("test1").runCommand({listCollections: 1});
         assert.commandWorked(res);
 
-        // Remove system.indexes collection (which exists in mmap)
-        // Indexes are checked separately below.
-        var collections = res.cursor.firstBatch.filter(coll => coll.name != 'system.indexes');
+        var collections = res.cursor.firstBatch;
 
         // Sort collections by name.
         collections.sort(sortByName);
@@ -145,8 +143,7 @@
         assert.eq(0, toShard.getDB("test1").bar.count(), "to shard has data before move");
 
         var listCollsFrom = fromShard.getDB("test1").runCommand({listCollections: 1});
-        var fromColls =
-            listCollsFrom.cursor.firstBatch.filter(coll => coll.name != 'system.indexes');
+        var fromColls = listCollsFrom.cursor.firstBatch;
         fromColls.sort(sortByName);
         var baruuid = fromColls[0].info.uuid;
         var foouuid = fromColls[1].info.uuid;
@@ -194,8 +191,7 @@
         assert.eq(0, toShard.getDB("test1").bar.count(), "to shard has data before move");
 
         var listCollsFrom = fromShard.getDB("test1").runCommand({listCollections: 1});
-        var fromColls =
-            listCollsFrom.cursor.firstBatch.filter(coll => coll.name != 'system.indexes');
+        var fromColls = listCollsFrom.cursor.firstBatch;
         fromColls.sort(sortByName);
         var baruuid = fromColls[0].info.uuid;
         var foouuid = fromColls[1].info.uuid;
diff --git a/jstests/sharding/sharding_system_namespaces.js b/jstests/sharding/sharding_system_namespaces.js
index b46487dacd8..d44f1150d64 100644
--- a/jstests/sharding/sharding_system_namespaces.js
+++ b/jstests/sharding/sharding_system_namespaces.js
@@ -1,12 +1,6 @@
-// SERVER-16498 d_migrate.cpp should not rely on system.namespaces
-//
 // This test creates a sharded collection with wiredtiger options.
 // When the chunks of this collection get migrated to the other shard,
 // the other shard should create the collection with the same options.
-// However, before SERVER-16498, the receiver relies on checking
-// system.namespaces on the donor, which is empty on wiredtiger.
-// As a result, the new collection created on receiver has different
-// options.
 
 var st = new ShardingTest({shards: 2});
 
diff --git a/jstests/sharding/stats.js b/jstests/sharding/stats.js
index 26bd656ac4d..76c64c8b41f 100644
--- a/jstests/sharding/stats.js
+++ b/jstests/sharding/stats.js
@@ -84,10 +84,8 @@
            'indexDetails should not be present in s.shard1.shardName: ' +
                tojson(x.shards[s.shard1.shardName]));
 
-    a_extras =
-        a.stats().objects - a.foo.count();  // things like system.namespaces and system.indexes
-    b_extras =
-        b.stats().objects - b.foo.count();  // things like system.namespaces and system.indexes
+    a_extras = a.stats().objects - a.foo.count();
+    b_extras = b.stats().objects - b.foo.count();
     print("a_extras: " + a_extras);
     print("b_extras: " + b_extras);
 
diff --git a/jstests/tool/dumprestoreWithNoOptions.js b/jstests/tool/dumprestoreWithNoOptions.js
index a1782d3ff7c..e6fdbd87ca8 100644
--- a/jstests/tool/dumprestoreWithNoOptions.js
+++ b/jstests/tool/dumprestoreWithNoOptions.js
@@ -13,10 +13,6 @@ t = new ToolTest("dumprestoreWithNoOptions");
 t.startDB("foo");
 db = t.db;
 
-// We turn this off to prevent the server from touching the 'options' field in system.namespaces.
-// This is important because we check exact values of the 'options' field in this test.
-db.adminCommand({setParameter: 1, newCollectionsUsePowerOf2Sizes: false});
-
 dbname = db.getName();
 dbname2 = "NOT_" + dbname;