run an action every 30 seconds

[michalkraus]

Thanks for your options

> 3) Use a heartbeat solution - http://linux-ha.org/wiki/Main_Page

I have API between the Nginx and the second (control) server. I use RPC
interface. I need just send a RPC request (with status infrmation) to
the control server. I think that heartbeat is too robust.

> 4) Use cron to start a script which does the test, sleeps for 30s,
then does 
> the test again, then dies (to be restarted by cron
> at the next minute)

This option seems to be the best but is any possibility the nginx to do
it in its own?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,173142,173166#msg-173166