A standard administration task is to stop and start the WebServer where the WebAgent is running.
If you have multiple Apache instance running on the same box that has webagent configured you may have some problem to stop them
The stop command could take sometime and you would need to manually kill the LLAWP process and then clean semaphores.
Why ?
This is due to the fact that the webagent is using the serverpath variable (located in the WebAgent.conf) to create identifiers for semaphores and those serverpath should be different between each webagent instance. The first chars of the serverpath should be different as the first chars are used to generate semaphore identifier. Otherwise the LLAWP process will have some problems to stop as he will no know which semaphore it will have to remove during the shutdown.
Julien.