Question

I can’t find a good clean way to lock a critical section in Django. I could use a lock or semaphore but the python implementation is for threads only, so if the production server forks then those will not be respected. Does anyone know of a way (I am thinking posix semaphores right now) to guarantee a lock across processes, or barring that a way to stop a Django server from forking.

Answer 1

You need a distributed lock manager at the point where your app suddenly needs to run on more than one service. I wrote elock for this purpose. There are bigger ones and others have chosen to ignore every suggestion and done the same with memcached.

Please don’t use memcached for anything more than light advisory locking. It is designed to forget stuff.

I like to pretend like filesystems don’t exist when I’m making web apps. Makes scale better.