child process killing task

Hi

we are using django and celery and 4 workers to achieve some tasks.

Sometimes, when we are running a quite long task (2 or 3 minutes), the task got killed by something, but we are not able to figure what.

Here is an extract of the log we got :

[2012-01-11 16:31:53,509: INFO/PoolWorker-1] haploid.createSendingTasks[46e8e...f8d]: get packet
[2012-01-11 16:31:53,511: INFO/PoolWorker-1] haploid.createSendingTasks[46e8e...f8d]: create task!
[2012-01-11 16:31:54,634: INFO/PoolWorker-2] child process calling self.run()
[2012-01-11 16:31:54,654: INFO/PoolWorker-2] haploid.notifs.send.ios[c54...21b]: -- handle Ios Notif !
[2012-01-11 16:31:54,686: INFO/MainProcess] Got task from broker: haploid.send.packet[b40a...deb5]

Just after the log "create task" the task createSendingTasks disapeared and we got this message "child process calling self.run()"

We have some few particularities :

• Celeryd is started with the option "-c 1" on each workers
• Some task on other workers are voluntarily (and savagely) killed with a "exit(1)". this usualy raise the "child process..." message on this worker

Does somebody have an idea about why the task got killed? And how to find why?

Could there be a link with an exit() on another worker ?

Thanks