Bug #75841 Disabling MTS must be safe
Submitted: 10 Feb 2015 14:54 Modified: 4 May 2015 13:46
Reporter: Andrii Nikitin Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server: Replication Severity:S4 (Feature request)
Version: OS:Any
Assigned to: CPU Architecture:Any

[10 Feb 2015 14:54] Andrii Nikitin
Description:
START SLAVE UNTIL SQL_AFTER_MTS_GAPS must be always executed when disabling MTS.
That happens because:
a.  STOP SLAVE doesn't guarantee that all workers will catch up according to bug #74528 
b. Workers may be at different positions in case if replication met an error
 
But this is very unfriendly requirement and it is very easy to lose some transactions when it is omitted.

Server must behave consistently and protect replication environment from accidental logical inconsistency. 
E.g. automatically execute SQL_AFTER_MTS_GAPS part whenever MTS gets disabled or at least show error.

How to repeat:
fr

Suggested fix:
fr
[4 May 2015 13:46] Andrii Nikitin
Progress on bug #74528 indicates that it is not required to run STAR SLAVE SQL_AFTER_MTS_GAPS when MTS is disabled (and only documentation issue did cause confusion).
Thus I close this FR as 'Not a bug'