Cleaning up semaphores and shared memory by process ID on Redhat OS

Products

• CA Single Sign On Secure Proxy Server (SiteMinder)
• CA Single Sign On SOA Security Manager (SiteMinder)
• CA Single Sign-On

Issue/Introduction

In most of the cases, custom Stop / Start scripts are used to restart the web servers with Symantec SiteMinder Agents (Apache ,Iplanet ,IBM HTTP server ...) . 

Some of these shutdown scripts uses a kill -9 to terminate the LLAWP process in case it takes longer then expected to shutdown.

The semaphores and shared memory must be cleaned up for the LLAWP process if a kill -9 was used before starting the Web Server and forking a new LLAWP .

This can be tricky if you have multiple Virtual Hosts configured with the agent as you will need to determine what semaphores / shared memory to clean up that are linked to the LLAWP process in question.

 

Environment

Applies to SiteMinder 12.52 and 12.8 Web Agents on Linux

Resolution

Below is how to correlate the LLAWP PID to the created semaphores and shared memory.

• Semaphore Cleanup
  1. run "ipcs -s" to get all semid for the User apache in your case that still exists
  2. for each semid returned ,you can run "ipcs -s -i "  for example --> ipcs -s -i 4587567 that will give you the PID that the semaphore is attached to .If this matches the LLAWP Process ID ,Then you can proceed removing it 

semnum value ncount zcount pid

0       0     4      0     1957

            3. ipcrm -s semid 

 

• Shared Memory cleanup
  1. run ipcs -p .This will show you the shared memory attached to the process.
  2. perform an ipcrm -m shmkey to remove it