Stop all celery processes/workers correctly

[jirik]

It seems multiple celery processes is started in process.start_layman, but only one of them is killed

[index-git]

stackoverflow - I suggest option with import psutil

[jirik]

Another sources

• https://medium.com/squad-engineering/two-years-with-celery-in-production-bug-fix-edition-22238669601d
• https://docs.celeryproject.org/en/latest/userguide/workers.html#stopping-the-worker