Bug #76309 Log a warning if timer_overhead is huge
Submitted: 13 Mar 2015 7:51 Modified: 20 Nov 2015 10:06
Reporter: Daniël van Eeden (OCA) Email Updates:
Status: Verified Impact on me:
Category:MySQL Server: Performance Schema Severity:S4 (Feature request)
Version:5.6 OS:Any
Assigned to: CPU Architecture:Any

[13 Mar 2015 7:51] Daniël van Eeden
I've seen some situations where the TIMER_OVERHEAD column from the performance_schema.performance_timers table for the CYCLE timer had a unexpectedly high number.

This can cause a high performance_schema overhead.

How to repeat:
See description

Suggested fix:
Log a warning to the error log if the overhead for the CYCLE timer is more than 200.
[10 May 2015 13:35] Daniël van Eeden
This was observed with RHEL on VMWare ESXi. If I recall it correctly the processor was an Intel Xeon in a HP blade.