How to stop celery worker?

Question

I am running celery via redis. I start my worker like this:

celery multi start worker1 -A mypackage.tasks.tasks
celery multi v3.1.18 (Cipater)
> Starting nodes...
        > [email protected]: OK

And I kill it like this:

celery multi kill worker1
celery multi v3.1.18 (Cipater)
> [email protected]: DOWN

But the worker is actually still running. I can not start the worker again:

celery multi start worker1 -A mypackage.tasks.tasks
celery multi v3.1.18 (Cipater)
> Starting nodes...
ERROR: Pidfile (worker1.pid) already exists.
Seems we're already running? (pid: 29369)
        > [email protected]: OK

If I kill the process, everything is ok:

kill 29369

But that is too cumbersome: I need to know the PID. How to really kill the worker with the celery command line tool?

Solution

There's no way to stop the worker with celery multi command. You can get PID from pid file or from ps output, e.g.

ps auxww | grep '[c]elery worker' | awk '{print $2}' | xargs kill 

or

kill $(cat /path/to/worker.pid)

Comments

[Grég]

What?! According to the celery multi help message, there is a celery multi kill worker1 command. What is that supposed to do but to kill the worker?

[sartis]

celery.readthedocs.org/en/latest/userguide/… - it's not documented. I've checked with the source code, it does exactly the same but in python.

[DejanLekic]

That command actually does nothing. Try it and see. After celery multi kill you will still see the processes running...