Bug #74693 is this a code defect in calculate pending jobs size?
Submitted: 5 Nov 2014 3:07
Reporter: yx jiang Email Updates:
Status: Open Impact on me:
None 
Category:MySQL Server: Replication Severity:S3 (Non-critical)
Version:5.6.12 OS:Any
Assigned to: CPU Architecture:Any

[5 Nov 2014 3:07] yx jiang 
Description:
variable:mts_pending_jobs_size of class Relay_log_info 

in parallel mode, this variable is added/reduced in different thread 

in coordinator thread:rli->mts_pending_jobs_size= new_pend_size; 
in worker thread:rli->mts_pending_jobs_size -= ev->data_written; 
finally when stop slave, asserting that "DBUG_ASSERT(rli->mts_pending_jobs_size == 0);" 

In my opinion, this is a defact but will not lead to fatal error.

How to repeat:
when research in code

Suggested fix:
use mutex protection