Generating a Thread Dump Externally
If Confluence stops responding and you can't create a thread dump within Confluence (via Support Tools), you can create thread dumps outside the application. External thread dumps are also useful if you require information on locks being held or waited upon by threads.
On this page:
Generating thread dumps on Linux
To generate a thread dump on Linux (or Solaris or other Unixes):
Identify the java process that Confluence is running in.: This can be achieved by running a command similar to:
Use the process ID from the above to generate the thread dumps:
This won't kill your server (so long as you included the "-3" option with no space in between).
Generating thread dumps on windows
Generating a thread dump using our scripts
We now have scripts for generating a series of thread dumps externally on Windows. Check out this BitBucket Repository for more information.
Generating a thread dump from the console
If you are not running Confluence as a service, you can generate a thread dump directly in the console.
Click the console window and press <CTRL>+BREAK (or SHIFT+CTRL+PAUSE on some keyboards). The thread dump will print directly to the console.
Generating a thread dump using jstack
The JDK (Java Development Kit) includes jstack, which is used for generating thread dumps.
To generate a thread dump using jstack:
- Identify the process. Launch the task manager by, pressing
Ctrl + Shift + Escand find the Process ID of the Java (Confluence) process. (If you can't see the PID column right click a column heading in Task Manager and choose PID).
Run jstack <pid> to Capture a Single Thread Dump. This command will take one thread dump of the process id <pid>, in this case the pid is 22668:
This will create a file called threaddump.txt to your current directory.
Thread dumps appear in the catalina.out file in the application directory's logs folder. Search for "thread dump" in the log file for the beginning of the dump.
Often Support may ask you to generate a sequence of thread dumps over a short period, so that they can compare what each dump contains and to look for any long running threads that could be the cause of the performance issue.
You can manually generate multiple thread dumps by executing the command repeatedly, but it is often easier to use a small script to automate the process. Here's an example that you can adapt to run on your Linux server:
Thread dump analysis tools
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