How should self._check_connection_ok() -> the connection is closed be handled?

[paulzakin]

Hey @medihack and @ewjoachim!

Got another quick question for you. Very occassionally - maybe like once every three weeks, Procrastinate will get "stuck" for lack of a better word on a closed connection. It will use that closed connection for every invocation of the recurring task. If the recurring task runnings every five minutes, you will get an error that looks like that every five minutes and so on.

Honestly, I'm not even sure this is a Procrastinate issue - could easily be a psycopg one. Or something weird we are doing!

Hence, this is more a question of like - how should Procrastinate handle this? Or should it be a thing for the end user to handle? Is it possible to force a Procrastinate process to restart within a task itself?

It is possible this just goes away in v3 - we are still on 2.15.1 - but I wanted to pick your guys brains. Not urgent at all!

Rough stack trace

2025-02-22T18:01:00.666Z | File "/.venv/lib/python3.13/site-packages/django/db/backends/postgresql/base.py", line 429, in create_cursor
-- | --
  | 2025-02-22T18:01:00.666Z | cursor = self.connection.cursor()
  | 2025-02-22T18:01:00.666Z | File "/.venv/lib/python3.13/site-packages/psycopg/connection.py", line 213, in cursor
  | 2025-02-22T18:01:00.666Z | self._check_connection_ok()
  | 2025-02-22T18:01:00.666Z | ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  | 2025-02-22T18:01:00.666Z | File "/.venv/lib/python3.13/site-packages/psycopg/_connection_base.py", line 532, in _check_connection_ok
  | 2025-02-22T18:01:00.666Z | raise e.OperationalError("the connection is closed")
  | 2025-02-22T18:01:00.666Z | django.db.utils.OperationalError: the connection is closed
  | 2025-02-22T18:01:00.672Z | Job validation:recurring_validation[4715381](timestamp=1740247260) ended with status: Error, lasted 0.006 s
  | 2025-02-22T18:01:00.672Z | Traceback (most recent call last):
  | 2025-02-22T18:01:00.672Z | File "/.venv/lib/python3.13/site-packages/django/db/backends/base/base.py", line 298, in _cursor
  | 2025-02-22T18:01:00.672Z | return self._prepare_cursor(self.create_cursor(name))
  | 2025-02-22T18:01:00.672Z | ~~~~~~~~~~~~~~~~~~^^^^^^
  | 2025-02-22T18:01:00.672Z | File "/.venv/lib/python3.13/site-packages/django/utils/asyncio.py", line 26, in inner
  | 2025-02-22T18:01:00.672Z | return func(*args, **kwargs)
  | 2025-02-22T18:01:00.672Z | File "/.venv/lib/python3.13/site-packages/django/db/backends/postgresql/base.py", line 429, in create_cursor
  | 2025-02-22T18:01:00.672Z | cursor = self.connection.cursor()
  | 2025-02-22T18:01:00.672Z | File "/.venv/lib/python3.13/site-packages/psycopg/connection.py", line 213, in cursor
  | 2025-02-22T18:01:00.672Z | self._check_connection_ok()
  | 2025-02-22T18:01:00.672Z | ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  | 2025-02-22T18:01:00.672Z | File "/.venv/lib/python3.13/site-packages/psycopg/_connection_base.py", line 532, in _check_connection_ok
  | 2025-02-22T18:01:00.672Z | raise e.OperationalError("the connection is closed")
  | 2025-02-22T18:01:00.672Z | psycopg.OperationalError: the connection is closed

[paulzakin]

It happened again today - very odd. We are going to switch to v3 and see if that solves the problem.

[paulzakin]

@medihack and @ewjoachim - v3

[ewjoachim]

(v3 as it "v3 soved the issue ? If so, 🎉 )

[paulzakin]

Unknown at this time - but hopefully! We are on v3 with smooth sailing thus far :)

[ewjoachim]

🤞 then