pt-table-checksum doesn't work with autocommit=0

[Matthew B]

When MySQL is operating in autocommit=0 mode, as defined in /etc/my.cnf, pt-table-checksum will not work as pt-table-checksum does not execute COMMIT statements.

Suggested fix: Add COMMIT after all checksum statements executed by the script when autocommit=0 (or just do it all the time)

Suggested fix: As pt-table-checksum will force binlog format = RBR, likewise, pt-t-c should force autocommit=1 for its sessions

[Carlos Salguero (carlos-salguero)]

Also, if autocommit = 0, CPU usage goes to 100%
  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
28917 karl 20 0 104416 35116 9160 R 100,0 0,2 7:53.38 perl

[Matthew B (utdrmac)]

CPU spins up because when running pt-t-c on master, it continuously waits/contacts each slave looking for the checksums which never come because there was no commit. ouch!

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PT-730