Performance degradation metrics when using PMI
 Technote (troubleshooting)
 
Problem(Abstract)
Ballpark performance degradation metrics when using PMI, JVMPI and PMI request metrics with ARM.
 
Resolving the problem
PMI overhead is 3.0% when using the standard level setting, where most of the counters are enabled except for those with maximum level, and when running Tivoli® Performance Viewer at the same time. When JVMPI counters are enabled, significant performance degradation is observed.
JVMPI has 4 types of data: GC, Thread, Object, and Monitor. In a full JVMPI configuration where all 4 are enabled, the impact from the full JVMPI data is about 55%.

For PMI request metrics with ARM enabled, and no filters (instrumenting all requests), the overhead in WebSphere® Application Server 5.1.x is in approximately 7%. This overhead can be further mitigated by using the filtering capabilities.

If both PMI and PMI request metrics are enabled, the expected added performance degradation is 10%.
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > PMI/Performance Tools
Operating system(s): Windows
Software version: 6.1.1
Software edition:
Reference #: 1206317
IBM Group: Software Group
Modified date: Jan 15, 2008