Bug #44770 innodb_buffer_cache_hit_rate_not_optimal advisor needs uptime check

• Submitted: 11 May 2009 0:12
• Modified: 7 Aug 2009 9:24
• Reporter: Roel Van de Paar
• Status: Closed
• Category: MySQL Enterprise Monitor: Advisors/Rules
• Severity: S3 (Non-critical)
• Version: 2.0.5.7153
• OS: Any
• Assigned to: Andy Bang
• CPU Architecture: Any

[11 May 2009 0:12] Roel Van de Paar

Description:
Expression:
(100-((%Innodb_buffer_pool_reads% / %Innodb_buffer_pool_read_requests%)*100))

For: innodb_buffer_cache_hit_rate_not_optimal advisor 

Needs an uptime check, otherwise a premature 'info' may fire (Some text changed for privacy purposes):

Time: 2009-01-01 01:01:01 GMT 
Advisor: Memory Usage - innodb_buffer_cache_hit_rate_not_optimal....
Thresholds Critical : 75 Info : 95 Warning : 85 
Frequency : 00:05:00 
Expression (100-((%Innodb_buffer_pool_reads% / %Innodb_buffer_pool_read_requests%)*100)) < THRESHOLD 
Evaluated Expression (100-((243 / 3534)*100)) < 95

How to repeat:
With values above rule should fire again.

Suggested fix:
Change expression to:

(%Uptime% > 10800) && (100-((%Innodb_buffer_pool_reads% / %Innodb_buffer_pool_read_requests%)*100))

[11 May 2009 21:22] Andy Bang

In 2.0: Pushed up to revision 270.
In 2.1: Pushed up to revision 264.

Please let me know when both the 2.0 and 2.1 versions are tested so we can upload the fixes to the Enterprise website for customers.

[14 May 2009 2:21] Keith Russell

Patch installed in versions => 2.1.0.1039.

[15 May 2009 23:36] Marcos Palacios

Verified fixed in advisor bundle 2.1.0.1039.

Advisor: Memory Usage
Rule:    InnoDB Buffer Cache Has Sub-Optimal Hit Rate

Setting back to 'Patch pending' waiting for the next 2.0 build.

[31 Jul 2009 2:48] Enterprise Tools JIRA Robot

Keith Russell writes: 
Patch installed in versions => 2.0.6.7159.

[4 Aug 2009 20:53] Enterprise Tools JIRA Robot

Bill Weber writes: 
verified uptime check added to 2.1.0.7159 advisor bundle

[4 Aug 2009 21:05] Enterprise Tools JIRA Robot

Marcos Palacios writes: 
Above referenced advisor bundle was meant as "2.0.6.7159" (for the benefit of the bugs DB record).

[7 Aug 2009 9:24] Tony Bedford

An entry was added to the 2.0.6 and 2.1.0 changelogs:

The Rule “InnoDB Buffer Cache Hit Rate Not Optimal” in the “Memory Usage” Advisor did not contain an uptime check. This resulted in premature firing of an info event.