IBM Monitoring and Diagnostic Tools for Java - Diagnostics Collector

The JVM automatically starts the Diagnostics Collector after detecting a runtime problem and producing diagnostic data. The Diagnostics Collector gathers diagnostic data files produced by the JVM and stores them in a single zip file.

If a system dump is produced, the Diagnostics Collector runs jextract on the dump and collects the jextract output. There is an option to disable this behaviour if jextract is not required. All actions are logged in a text file, which is also copied into the output zip file.

The Diagnostics Collector gathers system dumps, Javadumps, heap dumps, verbose GC log (if present) and JVM trace files that match the timestamp for the Java problem that caused the collector to start. The Diagnostics Collector copies the diagnostic files it finds into a single output zip file. The output file is named using the type of problem that occurred, the timestamp of the problem event and the process ID of the Java application, for example:
java.gpf.20081219.105104.9221.zip

At JVM start up, the Diagnostics Collector runs a Diagnostic Configuration Check. It checks for any settings that disable Java diagnostics. If any are found, a warning is printed on stderr and in the JavaDiagnosticsCollector.log file. Fix the settings identified by any warning messages before restarting your Java application. Fixing warnings makes it more likely that the right data is available for IBM Support to diagnose a Java problem.

The UserGuide.txt file in the download package gives more detailed information.

IBM SDK for Java version 5.0 or version 6.0

These instructions apply to Java 6 up to and including SR5, and to Java 5 up to and including SR10. If you are using a newer Java version, refer to the Diagnostic Guide (http://www.ibm.com/developerworks/java/jdk/diagnosis/) for instructions on how to enable the Diagnostics Collector.

To enable the Diagnostics Collector for Java 6 up to and including SR5, or Java 5 up to and including SR10:

1. Choose an install directory that is accessible to the user id that your Java application runs with.
   
2. Create the install directory if necessary.
   
3. Copy the download package to the install directory.a
   
4. Unzip the download package:
   unzip JavaDiagnosticsCollector_v1.0.zip
   
5. Ensure the user id that your Java application runs with has read permission for the installed files.

1. Edit the options file:
   java_dc_options.txt
   Replace the string <INSTALL_DIR> in the options file with the path to the directory where you installed the package.
   
2. In your Java application runtime configuration, add the following java command line option to enable the Java Diagnostics Collector:
   -Xoptionsfile=<INSTALL_DIR>/java_dc_options.txt
   Again, replace <INSTALL DIR> with the path to the directory where you unzipped the package.
   
   If you already use a -Xoptionsfile setting, add the contents of java_dc_options.txt to your existing java options file.