Collecting Javacore from IBM MQ Explorer

For certain issues, it is useful to collect a Javacore file from IBM MQ Explorer to check the status of the internal threads within the user interface.

About this task

We should collect Javacore only when asked to do so by the IBM Service Representative. The output location for the Javacore depends on the platform that IBM MQ Explorer is running on:

• On Linux, the Javacore is generated in the current working directory, which is typically the user's home directory. For example:
  • Directory: /home/mquser/
  • Filename example: javacore.20200108.101650.31132.0001.txt

• On Windows, the Javacore is generated in the user's home directory. For example:
  • Directory: C:\Users\MQUser\
  • Filename example: javacore.20200108.101825.4100.0001.txt

To collect a Javacore, complete the following steps.

Procedure

1. Close IBM MQ Explorer.
2. On Linux:
   1. Use the command MQExplorer to run IBM MQ Explorer.
      • If we are running the IBM MQ Explorer that was installed as part of a full IBM MQ server installation, the MQExplorer command is in /opt/mqm/bin, where opt/mqm is the IBM MQ installation directory.
      • If we installed the stand-alone IBM MQ Explorer (MS0T SupportPac), the MQExplorer command is in MQ_EXPLORER_INSTALLATION_PATH, where MQ_EXPLORER_INSTALLATION_PATH is the stand-alone IBM MQ Explorer (MS0T SupportPac) installation path.

   2. Determine the process identifier for the IBM MQ Explorer process. The following example shows how to determine the process identifier for the current user:

      ps -u `whoami` | grep MQExplorer | awk ' { print $1 } '

      If we are not sure how to get the process identifier, contact the systems administrator.

   3. Run following the command to generate the Javacore:

      kill -3 <MQExplorer process identifier>

3. On Windows:
   1. Use the command MQExplorer -debug to run IBM MQ Explorer.
      • If we are running the IBM MQ Explorer that was installed as part of a full IBM MQ server installation, the MQExplorer command (MQExplorer.exe) is in the MQ_INSTALLATION_PATH/bin64 directory, where MQ_INSTALLATION_PATH is the IBM MQ installation path.
      • If we installed the stand-alone IBM MQ Explorer (MS0T SupportPac), MQExplorer.exe is in MQ_EXPLORER_INSTALLATION_PATH directory, where MQ_EXPLORER_INSTALLATION_PATH is the IBM MQ Explorer (MS0T SupportPac) installation path.

   2. When a command-line window appears for IBM MQ Explorer, set Windows focus on this window, and press Control+Break to generate a Javacore.

Parent topic: Troubleshooting

Related information

• MQExplorer (launch IBM MQ Explorer)