SERVER-37947 Fail gracefully when explain is used in transactions

2 files changed, 18 insertions, 8 deletions

diff --git a/jstests/sharding/aggregation_currentop.js b/jstests/sharding/aggregation_currentop.js
index f6f114f1e82..ef629106f23 100644
--- a/jstests/sharding/aggregation_currentop.js
+++ b/jstests/sharding/aggregation_currentop.js
@@ -331,20 +331,15 @@ TestData.skipAwaitingReplicationOnShardsBeforeCheckingUUIDs = true;
         }));
 
         // Test that $currentOp fails if a non-local readConcern is specified for any data-bearing
-        // target. When run on a mongoS with {localOps:true}, read concern is not applicable and is
-        // therefore ignored.
+        // target.
         const linearizableAggCmd = {
             aggregate: 1,
             pipeline: [{$currentOp: curOpSpec}],
             readConcern: {level: "linearizable"},
             cursor: {}
         };
-        if (isLocalMongosCurOp) {
-            assert.commandWorked(adminDB.runCommand(linearizableAggCmd));
-        } else {
-            assert.commandFailedWithCode(adminDB.runCommand(linearizableAggCmd),
-                                         ErrorCodes.InvalidOptions);
-        }
+        assert.commandFailedWithCode(adminDB.runCommand(linearizableAggCmd),
+                                     ErrorCodes.InvalidOptions);
 
         // Test that {idleConnections: false} returns only active connections.
         const idleConn = new Mongo(conn.host);
diff --git a/jstests/sharding/explain_cmd.js b/jstests/sharding/explain_cmd.js
index dece5acff72..2c5f63753b7 100644
--- a/jstests/sharding/explain_cmd.js
+++ b/jstests/sharding/explain_cmd.js
@@ -141,5 +141,20 @@
     });
     assert.commandFailed(explain, tojson(explain));
 
+    // Explain a changeStream, ensure an error is thrown under snapshot read concern which is the
+    // default read concern for a transaction.
+    const session = db.getMongo().startSession();
+    const sessionDB = session.getDatabase(db.getName());
+    explain = sessionDB.runCommand({
+        aggregate: "coll",
+        pipeline: [{$changeStream: {}}],
+        explain: true,
+        txnNumber: NumberLong(0),
+        startTransaction: true,
+        autocommit: false
+    });
+    assert.commandFailedWithCode(
+        explain, ErrorCodes.OperationNotSupportedInTransaction, tojson(explain));
+
     st.stop();
 })();