Required Data: Jenkins Hang Issue On Linux

1. - Check you have the required tools to run the script included in the $PATH

The script must run as the same user as Jenkins. In the next steps we will consider this user to be named jenkins. The following checks must be performed with this users.

The collectPerformanceData.sh script collects thread dumps using either the jstack, jcmd or jattach commands.

There are 2 options here:

The script works optimally when the following optional commands are available top, vmstat, netstat, nfsiostat, nfsstat and iostat.

2. - Download the collectPerformanceData.sh script.

3. - Make the script executable

The collectPerformanceData.sh script will need to be made executable by running: chmod +x collectPerformanceData.sh.

4. - Get the $JENKINS_USER and $JENKINS_PID

You can retrieve the PID running ps ax | grep -i java | grep -i -e jenkins -e cloudbees | grep war | awk '{print $1}'

5. - Check that the jenkins user has permissions in the directory where collectPerformanceData.sh is running

The collectPerformanceData.sh script will generate data in this directory. Alternatively you can make the script generate its output elsewhere by setting up the JENKINS_HANG_OUTPUT_DIR variable. In this case, the jenkins user should have rights to write in JENKINS_HANG_OUTPUT_DIR.

6. - If you are experiencing a hang or a poor performance issue please execute the script while the issue is occurring:

Run the collectPerformanceData.sh script as the jenkins user by running:

sudo -u jenkins sh collectPerformanceData.sh $JENKINS_PID

7. - Collect the archive generated and attach it to the ticket using our upload service

Example

Running ps ax | grep -i java | grep -i -e jenkins -e cloudbees | grep war | awk '{print $1}' we get:

We can now run the script, the user running Jenkins being jenkins

You can run the script without any arguments to validate your setup.

In addition to the process described for traditional platform, take into account the following considerations CloudBees CI on Modern: Performance Issues - High CPU / Blocked Threads.