tomcat causing CPU utilisation spikes
From time to time, CPU utilisation on our Pega application servers (EC2 instances running tomcat 8) spikes, and would normally remain at high cpu usage for a few hours then subside. This can then lead to what appears as a hung thread and the only way to clear it is to restart the tomcat service (see attached image 1).
I have tried investigating which threads might be causing this issue as per this article:
https://community1.pega.com/pegatube/support-guide-finding-thread-causing-cpu-spike
But have had no luck as the above video describes investigate a java thread while the issue we are experiencing appears to be directly related to tomcat where it is tomcat threads that are utilising the CPU resources, not java.exe threads as in the example of the video above (see attached image 2).
How can I determine if the issue is
1) Pega related not OS/Tomcat related
2) What the threads that are using the resources are actually doing.
***Updated by moderator: Lochan to update platform capability***
Pegasystems Inc.
IT
It should be the same, as such the video suggestions should apply here as well.
The only difference in the screenshots is that tomcat is executed as a windows service.
Please provide Tomcat JVM startup arguments (Java Options parameters) and collect repeated thread dumps with 10 seconds interval.
This can be done identifying by applying the following steps:
- Identify the JVM PID using jps java tool shipped with JDK
Note: You must run jps as the same user that is running TomcatC:\Users\Admin>jps.exe 4816 Bootstrap <TOMCAT_PID> 19804 Jps - Run jstack <pid> to Capture a single Thread Dump.
Note: You must run jstack as the same user that is running Tomcat
The command will take a thread dump of the process id <pid> (123456 in the example below) writing the output to file named threaddump_<n>.txt (threaddump_1.txt):C:\Users\Admin>jstack.exe -l 123456 > threaddump_1.txt - Repeat step #2 10 times with 10 seconds interval
Department of Justice
AU
Thanks you for response, and apologies for my late reply.
I ran jps.exe as per your instruction above, but not sure I understand what to do with points 2 and 3?
Pegasystems Inc.
IN
Hi,
It would be helpful if you can share logs with us.I would not suggest to share it over community but you can raise a SR to get the reason behind this.
Thanks,
Abhinav