Details
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Bug
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Status: Open (View Workflow)
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Major
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Resolution: Unresolved
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10.8.0
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None
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None
Description
1. Start server on 4 numa nodes.
2. TPS as reported by 10.6.6: 942187.16
3. TPS as reported by 10.8: 685072.85
4. Closer look suggested increased contention for MDL rwlock
10.8:
wait/synch/rwlock/sql/MDL_lock::rwlock | 2269649.2516 | 483785033 |
So per instance wait: 4.69
10.6:
wait/synch/rwlock/sql/MDL_lock::rwlock | 883513.5605 | 658128191 |
So per instance wait: 1.34
10.8 rw-lock wait is 3.5 times more. Not sure what is causing the increased contention for MDL_lock. Don't see any other mutex contention on InnoDB side or other mutexes.
10.8: 5595ed9d9f20aeb463ac26e075c9cba41927e85e
10.6.6: 21778b8aa88280458f2196aab93044149cf0a18c