MySQL Bugs: #53874: SETUP_INSTRUMENTS.TIMED='NO' should not change TIMER

Bug #53874	SETUP_INSTRUMENTS.TIMED='NO' should not change TIMER_WAIT in aggregations
Submitted:	21 May 2010 6:56	Modified:	8 Sep 2010 1:55
Reporter:	Marc ALFF	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Performance Schema	Severity:	S3 (Non-critical)
Version:	5.5.3-m3, 5.5.4-m3	OS:	Any
Assigned to:	Christopher Powers	CPU Architecture:	Any

Description:
When using the performance schema without timers,
the SUM/MIN/MAX/AVG TIMER_WAIT in aggregations are garbage instead of 0.

How to repeat:
update performance_schema.SETUP_INSTRUMENTS set TIMED='NO';
truncate performance_schema.EVENTS_WAITS_SUMMARY_BY_EVENT_NAME;
select * from performance_schema.EVENTS_WAITS_SUMMARY_BY_EVENT_NAME;

Suggested fix:
N/A

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/116305

3188 Christopher Powers	2010-08-19
      Bug#53874, "SETUP_INSTRUMENTS.TIMED='NO' should not change TIMER_WAIT in aggregations"
      
      end_*_wait() functions now honor TIMER_STATE_UNTIMED
     @ storage/perfschema/pfs.cc
        Don't aggregate stats if TIMER_STATE_UNTIMED

Code change looks appropriate and correct.

The end wait functions ignored the timer state when collecting stats such that, even when the 'TIMED' flag in the SETUP_INSTRUMENTS table was set to 'NO', stats were still aggregated.

The patch posted previously is incorrect, and should not be pushed.

Changing the bug status back to in progress.

What needs to happen is:

1) with ENABLED='YES' and TIMED='YES',
update the columns COUNT_STAR, MIN/AVG/MAX TIMER_WAIT

this worked before and after the proposed patch.

2) with ENABLED='YES' and TIMED='NO',
update the column COUNT_STAR only.

This was broken before the fix, because the MIN/AVG/MAX TIMER_WAIT
columns were updated with garbage (hence the bug report).

Now with the proposed patch, the column COUNT_STAR that *was* aggregated
is not updated any more.

The fix introduced a regression, and needs to be re worked.

Also, test cases need to be added to the test suite, to clarify the desired behavior here.

Pushed into mysql-5.5 5.5.6-m3 (revid:alik@ibmvm-20100825092002-2yvkb3iwu43ycpnm) (version source revid:alik@ibmvm-20100825092002-2yvkb3iwu43ycpnm) (merge vers: 5.5.6-m3) (pib:20)

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/116795

3193 Christopher Powers	2010-08-25
      Bug# 53874 "SETUP_INSTRUMENTS.TIMED='NO' should not change TIMER_WAIT
      
      Handle combined instrument states of ENABLED and/or TIMED:
      
      ENABLED TIMED  
        1       1   Aggregate stats, increment counter
        1       0   Increment counter
        0       1   Do nothing
        0       0   Do nothing 
       
     @ storage/perfschema/pfs.cc
        Aggregate stats only if state is both ENABLED and TIMED. If ENABLED
        but not TIMED, only increment the value counter.
     @ storage/perfschema/pfs_stat.h
        Split aggregate and counter increment into separate
        methods for performance.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/116920

3197 Christopher Powers	2010-08-26
      Bug# 53874 "SETUP_INSTRUMENTS.TIMED='NO' should not change TIMER_WAIT
      
      Handle combined instrument states of ENABLED and/or TIMED:
      
      ENABLED TIMED
      1 1 Aggregate stats, increment counter
      1 0 Increment counter
      0 1 Do nothing
      0 0 Do nothing 
     @ storage/perfschema/pfs.cc
        Aggregate stats only if state is both ENABLED and TIMED. If ENABLED
        but not TIMED, only increment the value counter.
     @ storage/perfschema/pfs_stat.h
        Split aggregate and counter increment into separate
        methods for performance.

Last patch 
  http://lists.mysql.com/commits/116920
approved, thanks for the fix.

Patch queued into:

mysql-trunk-bugfixing
mysql-next-mr-bugfixing

Also queued to:

mysql-5.5-bugfixing

Pushed into mysql-trunk 5.6.1-m4 (revid:alik@sun.com-20100830082732-n2eyijnv86exc5ci) (version source revid:alik@sun.com-20100830082732-n2eyijnv86exc5ci) (merge vers: 5.6.1-m4) (pib:21)

Pushed into mysql-next-mr (revid:alik@sun.com-20100830082745-n6sh01wlwh3itasv) (version source revid:alik@sun.com-20100830082745-n6sh01wlwh3itasv) (pib:21)

Pushed into mysql-5.5 5.5.7-m3 (revid:alik@sun.com-20100830082727-5ac4czrxl61w9wle) (version source revid:alik@sun.com-20100830082727-5ac4czrxl61w9wle) (merge vers: 5.5.7-m3) (pib:21)

Noted in 5.5.6, 5.6.1 changelogs.

Setting SETUP_INSTRUMENTS.TIMER = 'NO' caused TIMER_WAIT values for
aggregations to be NULL rather than 0.

Fixed in 5.5.7, not 5.5.6.