1 files changed, 84 insertions, 0 deletions
diff --git a/jstests/sharding/write_transactions_during_migration.js b/jstests/sharding/write_transactions_during_migration.js
new file mode 100644
index 00000000000..7c52628e05e
--- /dev/null
+++ b/jstests/sharding/write_transactions_during_migration.js
@@ -0,0 +1,84 @@
+/**
+ * Tests that session information are properly transferred to the destination shard while
+ * new writes are being sent to the source shard.
+ */
+
+load('./jstests/libs/chunk_manipulation_util.js');
+
+/**
+ * Test outline:
+ * 1. Pause migration.
+ * 2. Perform writes and allow it to be capture via OpObserver
+ * 3. Unpause migration.
+ * 4. Retry writes and confirm that writes are not duplicated.
+ */
+(function() {
+
+    "use strict";
+
+    var staticMongod = MongoRunner.runMongod({});  // For startParallelOps.
+
+    var st = new ShardingTest({shards: {rs0: {nodes: 1}, rs1: {nodes: 1}}});
+    st.adminCommand({enableSharding: 'test'});
+    st.ensurePrimaryShard('test', st.shard0.shardName);
+    st.adminCommand({shardCollection: 'test.user', key: {x: 1}});
+
+    pauseMoveChunkAtStep(st.shard0, moveChunkStepNames.reachedSteadyState);
+    var joinMoveChunk =
+        moveChunkParallel(staticMongod, st.s.host, {x: 0}, null, 'test.user', st.shard1.shardName);
+
+    var insertCmd = {
+        insert: 'user',
+        documents: [{x: 10}, {x: 30}],
+        ordered: false,
+        lsid: {id: UUID()},
+        txnNumber: NumberLong(34),
+    };
+
+    var testDB = st.getDB('test');
+    var insertResult = assert.commandWorked(testDB.runCommand(insertCmd));
+
+    var findAndModCmd = {
+        findAndModify: 'user',
+        query: {x: 30},
+        update: {$inc: {y: 1}},
+        new: true,
+        upsert: true,
+        lsid: {id: UUID()},
+        txnNumber: NumberLong(37),
+    };
+
+    var findAndModifyResult = assert.commandWorked(testDB.runCommand(findAndModCmd));
+
+    unpauseMoveChunkAtStep(st.shard0, moveChunkStepNames.reachedSteadyState);
+    joinMoveChunk();
+
+    var insertRetryResult = assert.commandWorked(testDB.runCommand(insertCmd));
+
+    assert.eq(insertResult.ok, insertRetryResult.ok);
+    assert.eq(insertResult.n, insertRetryResult.n);
+    assert.eq(insertResult.writeErrors, insertRetryResult.writeErrors);
+    assert.eq(insertResult.writeConcernErrors, insertRetryResult.writeConcernErrors);
+
+    assert.eq(1, testDB.user.find({x: 10}).itcount());
+    assert.eq(1, testDB.user.find({x: 30}).itcount());
+
+    var findAndModifyRetryResult = assert.commandWorked(testDB.runCommand(findAndModCmd));
+
+    assert.eq(findAndModifyResult.ok, findAndModifyRetryResult.ok);
+    assert.eq(findAndModifyResult.value, findAndModifyRetryResult.value);
+
+    // TODO: SERVER-30532: after adding upserted, just compare the entire lastErrorObject
+    var expectedLE = findAndModifyResult.lastErrorObject;
+    var toCheckLE = findAndModifyRetryResult.lastErrorObject;
+
+    assert.neq(null, toCheckLE);
+    assert.eq(findAndModifyResult.updatedExisting, findAndModifyRetryResult.updatedExisting);
+    assert.eq(findAndModifyResult.n, findAndModifyRetryResult.n);
+
+    assert.eq(1, testDB.user.findOne({x: 30}).y);
+
+    st.stop();
+
+    MongoRunner.stopMongod(staticMongod);
+})();