Core classes instrumentation

Owned by Copy Space for Confluence
May 20, 2015

from version 1.3

InspectIT is now able to instrument all Java classes, even the native (core) classes, with new instrumentation techniques coming in the version 1.3. Core class instrumentation is automatically activated and does not require any additional settings in the configuration file.

Benefits

The benefits of the core class instrumentation lay in several new possibilities. First of all, now all Exceptions can be instrumented by the inspectIT exception sensor. This means, that even core Java exceptions can be now caught and analyzed with inspectIT. Furthermore, some of the important Java APIs from the java. and javax. packages can now be instrumented, too. For example, the classes from Java Remote Method Invocation can be instrumented and performance of RMI analyzed.

Be careful with core class instrumentation

Note that special care needs to be used when instrumenting the core classes. It is highly discouraged to instrument any class from the java.lang. package, because this kind of instrumentation can bring a massive overload to the application.

Limitations

Note that even with the core classes instrumentation, the following classes will never be instrumented:

  • all inspectIT classes in the package info.novatec.inspectit.
  • all classes in the package sun.
  • java.lang.ThreadLocal
  • java.lang.ref.Reference

Installation instructions

For core class instrumentation to work it is necessary to include inspectit-agent.jar to the -Xbootclasspath/p: parameter of the Java virtual machine when running the monitored application on an application server. For standalone Java applications this options is not necessary. Please have a look at the Installation Guide for concrete installation instructions.

When starting the application, the inspectIT Agent will display the following message if the core instrumentation was successful:

Oct 6, 2011 6:13:09 PM info.novatec.inspectit.agent.javaagent.JavaAgent analyzeAlreadyLoadedClasses
INFO: inspectIT Agent: Instrumentation of core classes finished...