SERVER-34520 Forbid multi-document transactions run through mongoS

1 files changed, 57 insertions, 0 deletions

diff --git a/jstests/sharding/transactions_prohibited_in_sharded_cluster.js b/jstests/sharding/transactions_prohibited_in_sharded_cluster.js
new file mode 100644
index 00000000000..6ad97243043
--- /dev/null
+++ b/jstests/sharding/transactions_prohibited_in_sharded_cluster.js
@@ -0,0 +1,57 @@
+/**
+ * Verify that multi-statement transactions are disallowed on mongos.
+ */
+(function() {
+    'use strict';
+
+    const st = new ShardingTest({shards: 1, mongos: 1, config: 1, rsOptions: {nodes: 1}});
+    const mongos = st.s0;
+    const dbName = "test";
+    const collName = "coll";
+
+    // Start a session on the mongos.
+    const session = mongos.getDB(dbName).getMongo().startSession();
+    const sessionDb = session.getDatabase(dbName);
+    let txnNumber = 0;
+
+    // Unable to start a transaction via mongos with a read.
+    assert.commandFailedWithCode(sessionDb.runCommand({
+        find: collName,
+        readConcern: {level: "snapshot"},
+        txnNumber: NumberLong(txnNumber++),
+        startTransaction: true,
+        autocommit: false
+    }),
+                                 50841);
+
+    // Unable to start a transaction via mongos with a write.
+    assert.commandFailedWithCode(sessionDb.runCommand({
+        insert: collName,
+        documents: [{_id: 1}],
+        readConcern: {level: "snapshot"},
+        txnNumber: NumberLong(txnNumber++),
+        startTransaction: true,
+        autocommit: false
+    }),
+                                 50841);
+
+    // 'startTransaction' and 'autocommit' arguments are always rejected by mongos.
+    assert.commandFailedWithCode(sessionDb.runCommand({
+        find: collName,
+        readConcern: {level: "snapshot"},
+        txnNumber: NumberLong(txnNumber++),
+        autocommit: false
+    }),
+                                 50841);
+
+    assert.commandFailedWithCode(sessionDb.runCommand({
+        find: collName,
+        readConcern: {level: "snapshot"},
+        txnNumber: NumberLong(txnNumber++),
+        startTransaction: true
+    }),
+                                 50841);
+
+    st.stop();
+
+})();