Page cleaner worker threads are not instrumented for performance schema
Affects | Status | Importance | Assigned to | Milestone | ||
---|---|---|---|---|---|---|
MySQL Server |
Unknown
|
Unknown
|
||||
Percona Server moved to https://jira.percona.com/projects/PS | Status tracked in 5.7 | |||||
5.1 |
Invalid
|
Undecided
|
Unassigned | |||
5.5 |
Invalid
|
Undecided
|
Unassigned | |||
5.6 |
Invalid
|
Undecided
|
Unassigned | |||
5.7 |
Fix Released
|
Medium
|
Laurynas Biveinis |
Bug Description
Copy of https:/
[8 Jan 13:56] Laurynas Biveinis
Description:
Credit shared with Alexey Stroganov.
Page cleaner worker threads do not call pfs_register_
This means:
1) (if I recall correctly how PFS thread instrumentation works) no events by these threads are actually accounted.
2) they are invisible in PERFORMANCE_
If 1) is correct, then any results so far on 5.7 to gain insights into MT page cleaner performance by PFS are basically invalid. To verify 2), start server in default configuration, and query P_S.THREADS. You will see one cleaner thread there only. The three worker threads there are purge. The cleaner worker threads are not there.
How to repeat:
See above, check buf0flu.cc for buf_flush_
Suggested fix:
Add a new thread key, register cleaner worker threads with PFS.
Percona now uses JIRA for bug reports so this bug report is migrated to: https:/ /jira.percona. com/browse/ PS-3356