Thursday, August 30, 2018

Tips and Tricks for Thread Dumps

Tip 1#: To find out the number of threads spawned by the JVM, run the following command: ps -eLF
This command will also print a column called 'LWP ID' (light-weight process ID) that prints the thread-id and the CPU utilization of that thread. This same thread-id can be correlated in the thread-dump obtained from the JVM.

Tip 2#: The thread-dump can be obtained by using the following command: jstack PID
If you are using Spring Boot framework, then we can use the Actuator URLs to download the thread-dump.

Tip 3#: This thread-dump file can be uploaded to a cool online tool : http://fastthread.io/ which gives a beautiful report on the threads running inside the JVM that can be analyzed.