run code after transaction commit in Django

One possibility would be to subclass the transaction middleware so that it sends a custom signal on commit. Your code could listen for that signal, rather than post_save.

Hope this may help someone using Django 1.9 or later. Since 1.9 on_commit is available.

So basically you would be doing it like this:

from django.db import transaction

transaction.on_commit(
    lambda: send_msg_to_rabbitmqp(param1, param2, ...)
)

If you wish to keep post_save, you can still use on_commit:

@receiver(pre_save, sender=MyModel)
def my_handler(sender, instance, created, **kwargs):
    transaction.on_commit(
        lambda: send_msg_to_rabbitmqp(instance.id)
    )

I have implemented transaction signals (post_commit and post_rollback) by monkey patching django: http://gist.github.com/247844

django-transaction-hooks solves this problem for Django < 1.9, and the functionality is built into Django 1.9+:

from django.db import transaction

def do_something():
    pass  # send a mail, invalidate a cache, fire off a Celery task, etc.

transaction.on_commit(do_something)