Often there are situations arising where we need to determine the ulimit settings of a running application server process like determining the maximum number of file descriptors for a given process or generating a system core from a process.
In order to find out, we can follow the below steps I am listing down here
Step 1: Determine the Process ID (PID) of the IBM WebSphere Application Server process to be investigated.
If the PID is already known, proceed to step 2.
If the PID is unknown then inspect the contents of the following file to determine the PID:
<install_root>/profiles/<profile_name>/logs/<server_name>/<server_name>.pid
This file should exist if the server is currently running. Exceptional circumstances could lead to a situation where this file exists and the server is not running.
The number contained within this file is the PID of the running server. We can even execute :-
ps -ef | grep java or ps -ef | grep <server_name> which would give us the pid of the process.
Step 2: Once the PID is known, inspect the file at the following location:
Location: /proc/
The contents of this file is similar to the output of the ulimit -a command.This file will have a list of ulimit parameters and their associated values for the specified PID.
Limit Soft Limit
Max cpu time unlimited
Max file size unlimited
Max data size unlimited
Max stack size 10485760
Max core file size unlimited
Max processes unlimited
Max open files 8192
Limitations:
This method is only available to more recent versions of IBM WebSphere Application Server supported Linux operating systems.
There may be some incremental maintenance that can be applied to support this method prior to the above versions and maintenance levels as only major maintenance levels were tested.