LP #1278426: pt-table-checksum false reporting when used with 5.6 multithreaded replication

**Reported in Launchpad by Noel last update 13-12-2014 04:17:27

I have recently used 5.6 multithreaded replication in my environment. With the basic workflow of multithreaded replication each threads work per database schema. Suppose we have DB1 & DB2 on same Host with 3MultiThread Replication working. When we have pt-table-checksum run in such condition with a different DB name assuming perconaDB so a total of 3 DB per host due to multithreaded replication each thread will run DB specific sql from relay log without linear hierarchy due to which it doesnt get a constant checksum snapshot and may report false. Only solution i figured out is write a script to have the checksum table in each DB and run pt-table-checksum DB specific to get proper output in for loop. I cant have this solution work if im having huge DB nos in same host and it will be hard to manage such setup having multiple checksum table under each DB.