Running a cron every 30 seconds

Question

Ok so I have a cron that I need to run every 30 seconds.

Here is what I have:

*/30 * * * * /bin/bash -l -c \'cd /srv/last_song/releases/2012030813315         


        

Answer 1

Have a look at frequent-cron - it's old but very stable and you can step down to micro-seconds. At this point in time, the only thing that I would say against it is that I'm still trying to work out how to install it outside of init.d but as a native systemd service, but certainly up to Ubuntu 18 it's running just fine still using init.d (distance may vary on latter versions). It has the added advantage (?) of ensuring that it won't spawn another instance of the PHP script unless a prior one has completed, which reduces potential memory leakage issues.