1 files changed, 97 insertions, 44 deletions
diff --git a/jstests/multiVersion/clustered_collection.js b/jstests/multiVersion/clustered_collection.js
index 94d89c9a5fa..39f38eac5c1 100644
--- a/jstests/multiVersion/clustered_collection.js
+++ b/jstests/multiVersion/clustered_collection.js
@@ -1,6 +1,11 @@
 /**
- * Regression test validating that on 5.0, documents in a clustered collections whose RecordId
- * exceeds 127 bytes return an error code on access.
+ * Regression test validating that all general-purpose clustered collections must be dropped
+ * before downgrading to 5.0.
+ *
+ * It also validates that on 5.0, documents in a time series buckets collection whose RecordId
+ * exceeds 127 bytes return an error code on access. While there isn't a known use case for
+ * large binary string RecordId encoding on time series collection, this test case is useful for
+ * validating the RecordId KeyString encoding behaviour across versions.
  */
 
 (function() {
@@ -14,48 +19,96 @@ const defaultOptions = {
     noCleanData: true
 };
 
-const kCollName = 'system.buckets.clusteredColl';
+const kBucketsCollName = 'system.buckets.clusteredColl';
+const kClusteredCollName = 'clusteredColl';
 
 let mongodOptions5dot0 = Object.extend({binVersion: '5.0'}, defaultOptions);
-let mongodOptionslatest = Object.extend({binVersion: 'latest'}, defaultOptions);
-
-// Create a clustered collection in `latest' and insert a RecordId > 127 bytes
-// Then downgrade to 5.0 and validate the RecordId cannot be decoded as too large
-
-jsTestLog("Starting version: latest");
-let conn = MongoRunner.runMongod(mongodOptionslatest);
-assert.neq(
-    null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptionslatest));
-
-let db = conn.getDB('test');
-assert.commandWorked(db.createCollection(kCollName, {clusteredIndex: true}));
-assert.commandWorked(db[kCollName].createIndex({a: 1}));
-// 126 characters + kStringLike CType + NULL terminator == 128 bytes
-assert.commandWorked(db[kCollName].insertOne({_id: 'x'.repeat(126), a: 1}));
-assert.eq(1, db[kCollName].find({a: 1}).itcount());
-
-assert.commandWorked(db.adminCommand({setFeatureCompatibilityVersion: "5.0"}));
-MongoRunner.stopMongod(conn);
-
-jsTestLog("Starting version: 5.0");
-conn = MongoRunner.runMongod(mongodOptions5dot0);
-assert.neq(
-    null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot0));
-
-db = conn.getDB('test');
-assert.commandFailedWithCode(db.runCommand({find: kCollName, filter: {a: 1}}), 5577900);
-assert.commandWorked(db[kCollName].insertOne({_id: 'x'.repeat(12), a: 2}));
-
-let stopOptions = {skipValidation: true};
-MongoRunner.stopMongod(conn, 15, stopOptions);
-
-jsTestLog("Starting version: latest");
-conn = MongoRunner.runMongod(mongodOptionslatest);
-assert.neq(
-    null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptionslatest));
-
-db = conn.getDB('test');
-assert.eq(1, db[kCollName].find({a: 1}).itcount());
-assert.eq(1, db[kCollName].find({a: 2}).itcount());
-MongoRunner.stopMongod(conn);
+let mongodOptions5dot1 = Object.extend(
+    {binVersion: '5.1', setParameter: 'featureFlagClusteredIndexes=true'}, defaultOptions);
+
+// Create a clustered collection in 5.1, then downgrade to 5.0 and validate that the
+// server is unable to start up.
+// Then upgrade back to 5.1, drop the clustered collection and validate that the 5.0
+// server starts up correctly.
+function testGeneralPurposeClusteredCollection() {
+    // Create clustered collection on 5.1.
+    jsTestLog("[general-purpose clustered collection] Starting version: 5.1");
+    let conn = MongoRunner.runMongod(mongodOptions5dot1);
+    assert.neq(
+        null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot1));
+
+    let db = conn.getDB('test');
+    assert.commandWorked(
+        db.createCollection(kClusteredCollName, {clusteredIndex: {key: {_id: 1}, unique: true}}));
+
+    assert.commandWorked(db.adminCommand({setFeatureCompatibilityVersion: "5.0"}));
+    MongoRunner.stopMongod(conn);
+
+    // Expect 5.0 to fail due to the presence of a clustered collection.
+    jsTestLog("[general-purpose clustered collection] Starting version: 5.0");
+    assert.throws(
+        () => MongoRunner.runMongod(mongodOptions5dot0), [], "The server unexpectedly started");
+
+    // Restart on 5.1, drop the clustered collection.
+    jsTestLog("[general-purpose clustered collection] Starting version: 5.1");
+    conn = MongoRunner.runMongod(mongodOptions5dot1);
+    assert.neq(
+        null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot1));
+
+    db = conn.getDB('test');
+    assert.commandWorked(db.runCommand({drop: kClusteredCollName}));
+    MongoRunner.stopMongod(conn);
+
+    // Expect 5.0 to start up successfully as there's no clustered collection around.
+    jsTestLog("[general-purpose clustered collection] Starting version: 5.0");
+    conn = MongoRunner.runMongod(mongodOptions5dot0);
+    assert.neq(
+        null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot0));
+    MongoRunner.stopMongod(conn);
+}
+
+// Create a time series buckets collection in 5.1 and insert a RecordId > 127 bytes
+// Then downgrade to 5.0 and validate the RecordId cannot be decoded as too large.
+// Then upgrade back to 5.1 and validate correct operation.
+function testTimeSeriesBucketsCollection() {
+    jsTestLog("[time series buckets collection] Starting version: 5.1");
+    let conn = MongoRunner.runMongod(mongodOptions5dot1);
+    assert.neq(
+        null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot1));
+
+    let db = conn.getDB('test');
+    assert.commandWorked(db.createCollection(kBucketsCollName, {clusteredIndex: true}));
+    assert.commandWorked(db[kBucketsCollName].createIndex({a: 1}));
+    // 126 characters + kStringLike CType + NULL terminator == 128 bytes
+    assert.commandWorked(db[kBucketsCollName].insertOne({_id: 'x'.repeat(126), a: 1}));
+    assert.eq(1, db[kBucketsCollName].find({a: 1}).itcount());
+
+    assert.commandWorked(db.adminCommand({setFeatureCompatibilityVersion: "5.0"}));
+    MongoRunner.stopMongod(conn);
+
+    jsTestLog("[time series buckets collection] Starting version: 5.0");
+    conn = MongoRunner.runMongod(mongodOptions5dot0);
+    assert.neq(
+        null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot0));
+
+    db = conn.getDB('test');
+    assert.commandFailedWithCode(db.runCommand({find: kBucketsCollName, filter: {a: 1}}), 5577900);
+    assert.commandWorked(db[kBucketsCollName].insertOne({_id: 'x'.repeat(12), a: 2}));
+
+    let stopOptions = {skipValidation: true};
+    MongoRunner.stopMongod(conn, 15, stopOptions);
+
+    jsTestLog("[time series buckets collection] Starting version: 5.1");
+    conn = MongoRunner.runMongod(mongodOptions5dot1);
+    assert.neq(
+        null, conn, 'mongod was unable able to start with version ' + tojson(mongodOptions5dot1));
+
+    db = conn.getDB('test');
+    assert.eq(1, db[kBucketsCollName].find({a: 1}).itcount());
+    assert.eq(1, db[kBucketsCollName].find({a: 2}).itcount());
+    MongoRunner.stopMongod(conn);
+}
+
+testGeneralPurposeClusteredCollection();
+testTimeSeriesBucketsCollection();
 })();