Logging of UNIX Process IDs
Posted on 2008-06-13
In unix - and specifically HP-UX - is there extensive logging of ALL process IDs that are run? If so, where is that log kept?
That is the question, here are some specifics. I have a script that is run every 5 minutes out of cron, all day long. One of the very first things I do is echo the current script's PID ($$) to a log file. Then I check very carefully to see if that script is already running. It should NOT be - it is run every 5 minutes and takes about 40 seconds to complete. If it IS running, I loop for 30 seconds, up to 3 times, and check again to see if the 'other' instance of the script is running. If that 'other' instance is running after that 1.5 minutes, I bail out and send an email. If the 'other' disappears, the current script goes on to do its work.
The PROBLEM is - that 'other' instance sometimes shows up in my log. And, it simply should NOT be there. When I loop, I send the process id information to the log (ps -efx). I can see the current instance PID. The 'other' instance is a different PID. Where is it coming from?
If there was a full log of every single process, I'd like to find it, and try to determine exatly where that 'other' process came from, who started it, its parent process...whatever. I tried the cron log (/var/adm/cron/log) and that does not show what I am looking for.