[SOLVED] Cron run fails at random points, throws: Attempting to re-run cron while....

Nighteyes · 06-14-2012, 03:32 AM

Ok, so a bit of background to this:

I'm developing for Drupal (CMS), I've been though all my code, stepped through it, run it all locally, everything works fine.

I put it on the live box, and it starts to get weird. cron run starts fine, it runs fine to a certain point, and then apparently, while running, it tries to run again.

it throws: Attempting to re-run cron while it is already running.

Which is fine, you'd expect that if cron tries to run while already running, but the job that's currently running stops. It doesn't throw any errors, there are no PHP exceptions or anything, and its got me pretty much stumped.

To check what's going on, I added 4 watchdog entries to the code (for those not familiar, its a Drupal error report system. Watchdog writers an entry to the database at any given point)

The first entry for cron hitting the start of the module code
The second entry for cron starting a loop in the module
The third entry is the end of a loop
and the fourth is the end of that module cron run.

So it should look something like this: (it reads bottom up)

Code:

MMI_User_cron_End	06/14/2012 - 09:00	Hook_cron has ended	Anonymous (not verified)
MMI_User_cron	06/14/2012 - 09:00	cron ran though this user: Uid: 40 Name: Suigetsu...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron has started to go though this user: Uid: 40 Name...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron ran though this user: Uid: 39 Name: Cutie...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron has started to go though this user: Uid: 39 Name...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron ran though this user: Uid: 35 Name: Lady...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron has started to go though this user: Uid: 35 Name...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron ran though this user: Uid: 1 Name: SoC Darkord...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron has started to go though this user: Uid: 1 Name:...	Anonymous (not verified)	
cron	06/14/2012 - 09:00	uid 0 loop: MMI User cron looped 0 time(s) though the...	Anonymous (not verified)	
MMI_User_cron	06/14/2012 - 09:00	cron has started to go though this user: Uid: 0 Name:	Anonymous (not verified)	
MMI_User_cron_Start	06/14/2012 - 09:00	Hook_cron has started	Anonymous (not verified)

instead it gets to a random point, and then stops. it might be after it has started a loop, it might be after its ended a loop, its always on a different pass, and its always when a new cron job attempts to start.

I hope all that makes some sort of sense, Any help would be much appreciated.

extra bits:

Cron tab: 0,30 * * * * wget -O - -q -t 10 http://www.theknightsofliberty.org/m...ron_key=****** >/dev/null 2>&1

Im running Cpanel

Hosting: Siteground (aweful, i know)

nick2day · 06-16-2012, 05:50 AM

Some hosts will limit the amount of crons or running processes you have, some will even execute 'kill' commands to user PIDs that exceed a pre-determined time frame.

I wouldn't be suprised if this was what you're running into. Have you tried contacting your host?

Nighteyes · 06-22-2012, 05:08 AM

Sorry for the late reply, just back from holiday.

That sounds like the case to me, Siteground are useless at the best of times, and without being able to reproduce the bug locally using, as far as i can tell, the same setup there doesn't seem to be much else it reasonably could be.

Thanks for the input

, i will be changing hosts next month, need a bigger box and a better provider