MySQL Bugs: #116702: gtid_mode=on but autoposition is 0 MTS recovery perform unnecessary operations

Bug #116702	gtid_mode=on but autoposition is 0 MTS recovery perform unnecessary operations
Submitted:	19 Nov 2024 6:05	Modified:	19 Nov 2024 16:56
Reporter:	karry zhang (OCA)	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Replication	Severity:	S4 (Feature request)
Version:	8.0.40	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
When gtid_mode is on, replicated transactions must be GTID transactions. We don't need to fill the gap of sequence transacion, because when replay the Gtid_log_event, the transaction represented by gtid will be skipped.

But I see when auto_position is not set,  we still need to fill the gap. 

How to repeat:
The mts_recovery_groups function has the following code:

 if (global_gtid_mode.get() == Gtid_mode::ON && rli->mi &&
      rli->mi->is_auto_position()) {
    rli->mts_recovery_group_cnt = 0;
    return false;
  }

gtid_mode must be on and autoposition must be on to skip filling gaps.

Suggested fix:
When gtid_mode is on, we can skip filling gaps.

Hi,

Thanks for the suggestion, I'll log it as feature request