SERVER-49249 add js test single phase index build conflict during initial sync

1 files changed, 85 insertions, 0 deletions

diff --git a/jstests/replsets/initial_sync_index_conflict.js b/jstests/replsets/initial_sync_index_conflict.js
new file mode 100644
index 00000000000..c1af06307a1
--- /dev/null
+++ b/jstests/replsets/initial_sync_index_conflict.js
@@ -0,0 +1,85 @@
+/**
+ * Asserts that applying a single-phase createIndexes oplog entry doesn't cause initial-sync to fail
+ * if there is an ongoing two-phase index build started by the cloner with the same index specs.
+ * This may happen if the index was first created on the primary when the collection was empty, then
+ * subsequently dropped and recreated after the collection has documents.
+ */
+
+(function() {
+'use strict';
+
+load('jstests/libs/fail_point_util.js');
+load('jstests/noPassthrough/libs/index_build.js');
+
+const dbName = 'test';
+const collectionName = 'coll';
+
+// How many documents to insert on the primary prior to
+// starting initial-sync.
+const initialDocs = 10;
+// Batch-size used for cloning.
+// Used as a fail-point parameter as detailed below.
+const clonerBatchSize = 1;
+
+// Setting initialDocs larger than clonerBatchSize causes
+// the fail-point to be hit because we fetch
+// multiple batches in the InitialSyncer.
+
+// Start one-node repl-set.
+const rst = new ReplSetTest({nodes: 1});
+rst.startSet();
+rst.initiate();
+const primary = rst.getPrimary();
+const primaryDB = primary.getDB(dbName);
+const primaryColl = primaryDB.getCollection(collectionName);
+
+// Add a secondary.
+const secondary = rst.add({
+    rsConfig: {votes: 0, priority: 0},
+    setParameter: {numInitialSyncAttempts: 1},
+});
+secondary.setSecondaryOk();
+const secondaryColl = secondary.getDB(dbName).getCollection(collectionName);
+
+// We set the collectionClonerBatchSize low above, so we will definitely hit
+// this fail-point and hang after the first batch is applied. While the
+// secondary is hung we clone the problematic document.
+const failPoint = configureFailPoint(
+    secondary, 'initialSyncHangBeforeCopyingDatabases', {nss: secondaryColl.getFullName()});
+rst.reInitiate();
+failPoint.wait();
+
+// Create the index using the empty collection fast path. The index build should be replicated
+// in a single createIndexes oplog entry.
+assert.commandWorked(primaryColl.createIndex({a: 1}));
+
+assert.commandWorked(primaryColl.insert({_id: 0, a: 0}));
+
+// Start a two-phase index build using the same spec when the collection has documents.
+// Use a failpoint to keep the index build from finishing when we resume initial sync on
+// the secondary.
+assert.commandWorked(primaryColl.dropIndex({a: 1}));
+IndexBuildTest.pauseIndexBuilds(primary);
+IndexBuildTest.pauseIndexBuilds(secondary);
+const createIdx = IndexBuildTest.startIndexBuild(primary, primaryColl.getFullName(), {a: 1});
+IndexBuildTest.waitForIndexBuildToScanCollection(primaryDB, primaryColl.getName(), 'a_1');
+try {
+    // Resume initial sync. The createIndexes oplog entry will be applied.
+    failPoint.off();
+
+    assert.soon(function() {
+        return rawMongoProgramOutput().search(
+                   /Invariant failure.*indexSpecs.size\(\) > 1.*test.coll.*a_1.*multi_index_block\.cpp/) >=
+            0;
+    });
+} finally {
+    IndexBuildTest.resumeIndexBuilds(primary);
+    createIdx();
+}
+
+IndexBuildTest.assertIndexes(primaryColl, 2, ['_id_', 'a_1']);
+
+rst.stop(secondary, undefined, {allowedExitCode: MongoRunner.EXIT_ABORT});
+TestData.skipCheckDBHashes = true;
+rst.stopSet();
+})();