Diagnostics AIX high CPU

WebSphere App Server v5.5 / 6.1 (based on JDK 1.5 or higher) has a CPU spike / usage issue whenever HP Diagnostics is enabled. Apparently this issue does not just effect Diagnostics, but any application that tries to use the -javaagent interface (so... Wily, ITCAM, etc). HP Diagnostics Probe v8.03 resolves this issue, but requires special / non-standard installation. Below are instructions on how to enable.

Completely uninstall the probe rather than upgrade. Upgrading to 8.03 and using the CPU fix does NOT work. You now have to run the JREInstrumenter, it is not optional since we are now doing a xbootclasspath. Also HeapWalker now works w/ AIX JVM.

  1. Run the JREInstrumenter and locate the JVM bundled with WebSphere if it is not found automatically. The default JVM location on AIX is in /opt/IBM/WebSphere/AppServer/java). Click the "Instrument" button, even though the instructions say this step is optional.
  2. _Modify the server.xml file(s) appropriate for your installation. For example, on AIX it could be /opt/IBM/WebSphere/AppServer/profiles/AppSrv01/config/cells/ovribmt11Node01Cell/nodes/ovribmt11Node01/servers/server1/server.xml. Find the "jvmEntries" element and set its "genericJvmArguments" property to say: "-Xbootclasspath/p:/opt/MercuryDiagnostics/JavaAgent/DiagnosticsAgent/classes/IBM/1.5.0:/opt/MercuryDiagnostics/JavaAgent/DiagnosticsAgent/classes/boot -Xshareclasses:none -agentpath:/opt/MercuryDiagnostics/JavaAgent/DiagnosticsAgent/lib/ppc-aix64/libjvmti.a". (This is where previously the "-javaagent" option went). Modify the paths according to your installation, of course. Please note that Heap Walker is now available and supported for this JVM.
    _
  3. Modify the server.policy file (for example, in /opt/IBM/WebSphere/AppServer/profiles/AppSrv01/properties) by adding the following lines at the end
    // Mercury Diagnostics 
    grant codeBase "file:/opt/MercuryDiagnostics/JavaAgent/DiagnosticsAgent/lib/probe-jmx.jar" { 
    permission java.security.AllPermission; 
    };

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This code was tested in the lab on WebSphere 6.1 running on AIX 5.3.

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