Bug 979436

Summary: [One-Off] BRMS has performance decrease after applied Roll Up patch BRMS_5.3.1_2_2013 (BZ-953308)
Product: [JBoss] JBoss Enterprise BRMS Platform 5 Reporter: Alessandro Lazarotti <alazarot>
Component: BRE (Expert, Fusion)Assignee: Mario Fusco <mfusco>
Status: CLOSED NOTABUG QA Contact: Lukáš Petrovický <lpetrovi>
Severity: high Docs Contact:
Priority: unspecified    
Version: BRMS 5.3.1CC: brms-jira
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Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2013-07-04 15:06:24 UTC Type: Support Patch
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 976824    
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Description Alessandro Lazarotti 2013-06-28 14:01:55 UTC
After applied the Roll Up patch BRMS_5.3.1_2_2013 the rule engine has decreased in 6% its performance.

This regression is related to BZs: Bug 976824 and Bug 969467

Comment 1 Mario Fusco 2013-07-01 10:25:37 UTC
The problem reported here https://bugzilla.redhat.com/show_bug.cgi?id=969467 was caused by a wrong synchronization pattern that, in order to be fixed, required a change in the policy in how locks are acquired, together with the introduction of a new type of lock. This caused a performance degradation that I partially addressed by tweaking the internal data structures of the before mentioned new lock. Unfortunately I don't see a way to avoid both the deadlock reported in that ticket and the remaining 6% of performance loss reported here. 

Of course performance is an important feature and we are striving to keep the rule engine as fast as possible, but at the same time we cannot trade correctness for performance.

Comment 3 Alessandro Lazarotti 2013-07-04 15:06:24 UTC
As commented by engineer and after some reviews, a minor loss of performance, which can vary between 3% to 6%, is expected due additional locks needed to fix Bug 969467. This value is not noticeable for most use cases. 

I am closing this ticket as "not a bug" status.