How is cron actually running?

Hey Patrick -

I just spun up a new private instance with one of the EC2 images - thanks so much for making those available!

I know in order for it to update and do other automated tasks there are scripts in the cron directory that are supposed to be run at specific intervals. I assumed there’d be some crontab entries, but I’m not seeing any. Then I saw a comment you made about how there’s no need to hook it up to actual cron, it is triggered automatically as agents poll for work.

Is that still the case? In the context of EC2 autoscaling, how will it ever know to spin up new agents (isn’t that managed by the scripts in /cron?) if there’s no agents polling to begin with?


It should still be the case. When a test is submitted to an autoscale test location, runtest.php should do the scaling up if needed.

If you really want to, you can set up crontab entries to wget/curl to localhost/cron/15min.php (and hourly.php) which will make sure the web UI auto-updates even when no agents are running. That’s the only case I can think of where it should need it.

Thanks Pat! That helps clear things up. I’ll see how things are going before I add in those hard cron entries, but I should tip others that it was nice to force upgrade the code (since the EC2 image was created in 2014) by manually running ‘sudo php hourly.php’ from that cron directory.

Oh, good point. I should probably freshen the image at some point and wire up cron just to keep things fresh from startup and when idle.

I’m planning on cutting a 3.0 release pretty soon since it has been a while and there have been a lot of big changes since the last official release so that would be a good time to release a new image.