SERVER-37872 Add targeted jstest for sharded transactions with afterClusterTime

1 files changed, 78 insertions, 0 deletions

diff --git a/jstests/sharding/transactions_causal_consistency.js b/jstests/sharding/transactions_causal_consistency.js
new file mode 100644
index 00000000000..88a7762d501
--- /dev/null
+++ b/jstests/sharding/transactions_causal_consistency.js
@@ -0,0 +1,78 @@
+// Verifies basic sharded transaction behavior with causal consistency.
+//
+// @tags: [
+//   requires_find_command,
+//   requires_sharding,
+//   uses_multi_shard_transaction,
+//   uses_transactions,
+// ]
+(function() {
+    "use strict";
+
+    const dbName = "test";
+    const collName = "foo";
+    const ns = dbName + "." + collName;
+
+    const st = new ShardingTest({shards: 2, mongos: 2});
+
+    // Set up a sharded collection with 2 chunks, [min, 0) and [0, max), one on each shard, with one
+    // document in each.
+
+    assert.commandWorked(st.s.adminCommand({enableSharding: dbName}));
+    st.ensurePrimaryShard(dbName, st.shard0.shardName);
+
+    assert.commandWorked(st.s.adminCommand({shardCollection: ns, key: {_id: 1}}));
+    assert.commandWorked(st.s.adminCommand({split: ns, middle: {_id: 0}}));
+    assert.commandWorked(
+        st.s.adminCommand({moveChunk: ns, find: {_id: 1}, to: st.shard1.shardName}));
+
+    assert.writeOK(st.s.getDB(dbName)[collName].insert({_id: -1}, {writeConcern: {w: "majority"}}));
+    assert.writeOK(st.s.getDB(dbName)[collName].insert({_id: 1}, {writeConcern: {w: "majority"}}));
+
+    // Verifies transactions using causal consistency read all causally prior operations.
+    function runTest(st, readConcern) {
+        jsTestLog("Testing readConcern: " + tojson(readConcern));
+
+        const session = st.s.startSession({causalConsistency: true});
+        const sessionDB = session.getDatabase(dbName);
+
+        // Insert data to one shard in a causally consistent session.
+        const docToInsert = {_id: 5};
+        assert.commandWorked(sessionDB.runCommand({insert: collName, documents: [docToInsert]}));
+
+        // Through a separate router move the chunk that was inserted to, so the original router is
+        // stale when it starts its transaction.
+        const otherRouter = st.s1;
+        assert.commandWorked(
+            otherRouter.adminCommand({moveChunk: ns, find: docToInsert, to: st.shard0.shardName}));
+
+        session.startTransaction({readConcern: readConcern});
+
+        // The transaction should always see the document written earlier through its session,
+        // regardless of the move.
+        //
+        // Note: until transactions can read from secondaries and/or disabling speculative snapshot
+        // is allowed, read concerns that do not require global snapshots (i.e. local and majority)
+        // will always read the inserted document here because the local snapshot established on
+        // this shard will include all currently applied operations, which must include all earlier
+        // acknowledged writes.
+        assert.docEq(docToInsert,
+                     sessionDB[collName].findOne(docToInsert),
+                     "sharded transaction with read concern " + tojson(readConcern) +
+                         " did not see expected document");
+
+        session.commitTransaction();
+
+        // Clean up for the next iteration.
+        assert.commandWorked(
+            st.s.adminCommand({moveChunk: ns, find: docToInsert, to: st.shard1.shardName}));
+        assert.writeOK(sessionDB[collName].remove(docToInsert));
+    }
+
+    const kAllowedReadConcernLevels = ["local", "majority", "snapshot"];
+    for (let readConcernLevel of kAllowedReadConcernLevels) {
+        runTest(st, {level: readConcernLevel});
+    }
+
+    st.stop();
+})();