// // Tests that a migration does not overwrite duplicate _ids on data transfer // var st = new ShardingTest({ shards : 2, mongos : 1 }); st.stopBalancer(); var mongos = st.s0; var shards = mongos.getDB( "config" ).shards.find().toArray(); shards[0].conn = st.shard0; shards[1].conn = st.shard1; var admin = mongos.getDB( "admin" ); var coll = mongos.getCollection( "foo.bar" ); assert( admin.runCommand({ enableSharding : coll.getDB() + "" }).ok ); printjson( admin.runCommand({ movePrimary : coll.getDB() + "", to : shards[0]._id }) ); assert( admin.runCommand({ shardCollection : coll + "", key : { skey : 1 } }).ok ); assert( admin.runCommand({ split : coll + "", middle : { skey : 0 } }).ok ); assert( admin.runCommand({ moveChunk : coll + "", find : { skey : 0 }, to : shards[1]._id }).ok ); var id = 12345; jsTest.log( "Inserting a document with id : 12345 into both shards with diff shard key..." ); assert.writeOK(coll.insert({ _id : id, skey : -1 })); assert.writeOK(coll.insert({ _id : id, skey : 1 })); printjson( shards[0].conn.getCollection( coll + "" ).find({ _id : id }).toArray() ); printjson( shards[1].conn.getCollection( coll + "" ).find({ _id : id }).toArray() ); assert.eq( 2, coll.find({ _id : id }).itcount() ); jsTest.log( "Moving both chunks to same shard..." ); var result = admin.runCommand({ moveChunk : coll + "", find : { skey : -1 }, to : shards[1]._id }); printjson( result ); printjson( shards[0].conn.getCollection( coll + "" ).find({ _id : id }).toArray() ); printjson( shards[1].conn.getCollection( coll + "" ).find({ _id : id }).toArray() ); assert.eq( 2, coll.find({ _id : id }).itcount() ); st.stop();