Stopping gearman workers nicely

Question

I have a number of Gearman workers running constantly, saving things like records of user page views, etc. Occasionally, I\'ll update the PHP code that is used by the Gearman w

Answer 1

I've been looking at this recently as well (though in perl with Gearman::XS). My usecase was the same as yours - allow a long-running gearman worker to periodically check for a new version of itself and reload.

My first attempt was just having the worker keep track of how long since it last checked the worker script version (an md5sum would also work). Then once N seconds had elapsed, between jobs, it would check to see if a new version of itself was available, and restart itself (fork()/exec()). This did work OK, but workers registered for rare jobs could potentially end up waiting hours for work() to return, and thus for checking the current time.

So I'm now setting a fairly short timeout when waiting for jobs with work(), so I can check the time more regularly. The PHP interface suggest that you can set this timeout value when registering for the job. I'm using SIGALRM to trigger the new-version check. The perl interface blocks on work(), so the alarm wasn't being triggered initially. Setting the timeout to 60 seconds got the SIGALRM working.