When a Java application has errors, it is often useful to be able to perform a thread dump to find out exactly what is happening in the JVM. A thread dump will show you which Java methods and lines are currently being executed giving you a good place to start looking for problems.
You can view and generate a thread dump from the Threads tab in the Maintenance screen.
Note: You may still get thread dumps even if you don't have access to the dotCMS back-end (during an outage, for example). Please see the recommended method of getting Java thread dumps for more information.
Summary Information
Select System -> Maintenance -> Threads tab to view the following summary thread information:
| Value | Description |
|---|---|
| System Startup Time | The date and time that the dotCMS system was started. |
| Thread Count - Current | Current number of running threads. |
| Thread Count - Peak | Highest number of running threads since startup. |
Press the Reload Sys Info button to update the summary thread information with current values.
Detailed Thread Information
To display detailed information on all individual threads, press the Reload Threads button. A list of each thread with its full stack trace is provided.
Copying Thread Information
You may wish to save the detailed thread information; for example, dotCMS support may request this information when helping you with some specific issues. To copy the detailed thread information, press the Select all button and then copy the information from your browser; you can then paste the thread information into a file or another window.
Addition Resources
If you are working with dotCMS support, dotCMS staff will analyze the thread dumps for you. However if you are running dotCMS from a source distribution or developing your own plugins, you may need to analyze the thread dumps yourself. The following articles provide useful information on how to analyze thread dumps:
