Periodic action under mod_perl

Question

How do I perform periodic actions under mod_perl, specifically Apache2?

For instance, I need to reload some data from remote location, process it, and store it in memory. Ideally, I don't want to do this while a request is being served.

I highly doubt alarm is never used across our codebase, so just setting up a periodic alarm won't work. Also external storage (like Redis/Memcached) can be fast but still not as fast as process's own memory.

I believe this can be done using some custom signal, pkill and cron. Signal handler execution may be postponed until cleanup phase if needed.

But maybe there's a more straightforward way? Something really obvious I don't see?

Answer 1

If you built the Perl you embedded into Apache with threading support, just create a thread in the startup script.

If not, it's going to be really complicated to make sure that every Apache process updates itself.