SERVER-41008: Check lastCommittedOpTime instead of awaitReplication for tests that prepare with {w: 1}

3 files changed, 35 insertions, 7 deletions

diff --git a/jstests/core/txns/libs/prepare_helpers.js b/jstests/core/txns/libs/prepare_helpers.js
index 1bbabf2d224..f6a33bbcfc6 100644
--- a/jstests/core/txns/libs/prepare_helpers.js
+++ b/jstests/core/txns/libs/prepare_helpers.js
@@ -123,6 +123,24 @@ const PrepareHelpers = (function() {
         }
     }
 
+    /**
+     * Waits for the oplog entry of the given timestamp to be majority committed.
+     */
+    function awaitMajorityCommitted(replSet, timestamp) {
+        print(`Waiting for majority commit point to advance past the given timestamp ${timestamp}`);
+        const primary = replSet.getPrimary();
+        assert.soon(() => {
+            const ts = assert.commandWorked(primary.adminCommand({replSetGetStatus: 1}))
+                           .optimes.lastCommittedOpTime.ts;
+            if (ts >= timestamp) {
+                return true;
+            } else {
+                print(`Awaiting lastCommittedOpTime.ts, now at ${ts}`);
+                return false;
+            }
+        }, "Timeout waiting for majority commit point", ReplSetTest.kDefaultTimeoutMS, 1000);
+    }
+
     return {
         prepareTransaction: prepareTransaction,
         commitTransaction: commitTransaction,
@@ -131,6 +149,7 @@ const PrepareHelpers = (function() {
         oplogSizeBytes: oplogSizeBytes,
         replSetStartSetOptions: {oplogSize: oplogSizeMB},
         growOplogPastMaxSize: growOplogPastMaxSize,
-        awaitOplogTruncation: awaitOplogTruncation
+        awaitOplogTruncation: awaitOplogTruncation,
+        awaitMajorityCommitted: awaitMajorityCommitted
     };
 })();
diff --git a/jstests/replsets/prepare_transaction_index_build.js b/jstests/replsets/prepare_transaction_index_build.js
index 543d9b919e9..cac5445c139 100644
--- a/jstests/replsets/prepare_transaction_index_build.js
+++ b/jstests/replsets/prepare_transaction_index_build.js
@@ -48,6 +48,7 @@
     assert.commandWorked(sessionColl.insert({x: 1000}));
 
     const prepareTimestamp = PrepareHelpers.prepareTransaction(session, {w: 1});
+    jsTestLog("Prepared a transaction at " + prepareTimestamp);
 
     jsTestLog("Unblocking index build.");
 
@@ -55,11 +56,13 @@
     secondary.getDB("admin").runCommand(
         {configureFailPoint: 'hangAfterStartingIndexBuild', mode: 'off'});
 
-    jsTestLog("Waiting for all index builds to finish on all nodes.");
-
-    // wait for the index build to finish; we know it's done if the prepare has finished on the
-    // secondary.
-    replTest.awaitReplication();
+    // It's illegal to commit a prepared transaction before its prepare oplog entry has been
+    // majority committed. So wait for prepare oplog entry to be majority committed before issuing
+    // the commitTransaction command. We know the index build is also done if the prepare has
+    // finished on the secondary.
+    jsTestLog(
+        "Waiting for prepare oplog entry to be majority committed and all index builds to finish on all nodes.");
+    PrepareHelpers.awaitMajorityCommitted(replTest, prepareTimestamp);
 
     jsTestLog("Committing txn");
     // Commit the transaction.
diff --git a/jstests/replsets/recover_prepared_transactions_startup_secondary_application.js b/jstests/replsets/recover_prepared_transactions_startup_secondary_application.js
index cd7a6ddefc0..215d97b5157 100644
--- a/jstests/replsets/recover_prepared_transactions_startup_secondary_application.js
+++ b/jstests/replsets/recover_prepared_transactions_startup_secondary_application.js
@@ -47,10 +47,12 @@
     session.startTransaction();
     assert.commandWorked(sessionColl.update({_id: 1}, {_id: 1, a: 1}));
     let prepareTimestamp = PrepareHelpers.prepareTransaction(session, {w: 1});
+    jsTestLog("Prepared a transaction at " + prepareTimestamp);
 
     session2.startTransaction();
     assert.commandWorked(sessionColl2.update({_id: 2}, {_id: 2, a: 1}));
     const prepareTimestamp2 = PrepareHelpers.prepareTransaction(session2, {w: 1});
+    jsTestLog("Prepared another transaction at " + prepareTimestamp2);
 
     const lsid = session.getSessionId();
     const txnNumber = session.getTxnNumber_forTesting();
@@ -71,7 +73,11 @@
 
     assert.commandWorked(
         primary.adminCommand({configureFailPoint: "disableSnapshotting", mode: "off"}));
-    replTest.awaitReplication();
+
+    // It's illegal to commit a prepared transaction before its prepare oplog entry has been
+    // majority committed. So wait for prepare oplog entry to be majority committed before issuing
+    // the commitTransaction command.
+    PrepareHelpers.awaitMajorityCommitted(replTest, prepareTimestamp2);
 
     jsTestLog("Checking that the first transaction is properly prepared");