IBM Support

Performance degradation metrics when using PMI

Troubleshooting


Problem

Approximate 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 JVMTI counters are enabled, significant performance degradation is observed.

JVMTI has 4 types of data: GC, Thread, Object, and Monitor. In a full JVMTI configuration where all 4 are enabled, the impact from the full JVMTI data is about 55%.

For PMI request metrics with ARM enabled, and no filters (instrumenting all requests), the overhead is 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%.

[{"Type":"MASTER","Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"ARM Category":[{"code":"a8m50000000L2DEAA0","label":"WebSphere Application Server traditional-All Platforms-\u003EPMI"}],"ARM Case Number":"","Platform":[{"code":"PF002","label":"AIX"},{"code":"PF016","label":"Linux"},{"code":"PF027","label":"Solaris"},{"code":"PF033","label":"Windows"}],"Version":"8.5.5;9.0.5"},{"Product":{"code":"SSNVBF","label":"Runtimes for Java Technology"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Component":"Java SDK","Platform":[{"code":"","label":""}],"Version":"","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
11 October 2023

UID

swg21206317