function moveChunk(st, fromMongod, toMongod, epoch) { var chunk = st.s.getDB( "config" ).chunks.findOne({shard: fromMongod.shardName}); assert (chunk, "no chunks on shard to move" ); epoch = epoch || chunk.lastmodEpoch; var cmd = { moveChunk: coll + "", from: fromMongod.host, to: toMongod.host, fromShard: fromMongod.shardName, toShard: toMongod.shardName, min: {x: chunk.min.x}, max: {x: chunk.max.x}, maxChunkSizeBytes: 52428800, shardId: chunk._id, configdb: st.config0.host, secondaryThrottle: true , waitForDelete: true , maxTimeMS: 0, epoch: epoch }; // moveChunk should fail with epoch that is not the same as the one in the chunk // if (!chunk.lastmodEpoch.equals(epoch)) { // assert .commandFailed(fromMongod.adminCommand(cmd), "moveChunk failed " + tojson(epoch)); //} else { assert .commandWorked(fromMongod.adminCommand(cmd), "moveChunk worked " + tojson(epoch)); //} } var st = new ShardingTest({name: "epoch" , shards: 2, chunkSize: 1}); st.stopBalancer(); var configDB = st.s.getDB( "config" ); var testDB = st.s.getDB( "test" ); var collName = "epoch" ; var coll = testDB[collName]; configDB.adminCommand({enableSharding: "test" }); configDB.adminCommand({movePrimary: "test" , to: "shard0000" }); configDB.adminCommand({shardCollection: coll + "", key: {x: 1}}); assert .commandWorked( configDB.adminCommand({split: coll + "", middle: {x: 100}}), "split" ); assert .commandWorked( configDB.adminCommand({moveChunk: coll + "", find: {x: 100}, to: " shard0001"}), "moveChunk" ); var collectionDoc = configDB.collections.findOne({_id: coll + ""}); var lastmodEpoch = collectionDoc.lastmodEpoch; moveChunk(st, st.d0, st.d1, "abc" ); // Works, should fail moveChunk(st, st.d1, st.d0, 12345); // Works, should fail moveChunk(st, st.d0, st.d1, lastmodEpoch); // Works st.stop();