Support celerycam for reconnecting db connenction if db connection is lost accidentally

[jxltom]

Currently if the database is not stable and connection is lost, celerycam can not reconnect db connection automatically and it can not work properly anymore. The error connection already closed will always be raised.

This PR supports to automatically reconnect db connection for celerycam if db connection is lost.

[Copilot]

Pull Request Overview

Adds automatic reconnection logic for Celery snapshot state handling when the Django database connection is lost.

• Imports connection and InterfaceError from Django.
• Wraps worker and task handling in a try/except to catch a closed connection.
• Closes the connection and logs a message so Django’s connection pooling can reconnect.

Comments suppressed due to low confidence (1)

djcelery/snapshot.py:141

• Ensure that a logger instance is defined or imported in this module before using logger.info(), otherwise this will raise a NameError at runtime.

logger.info(

[Copilot]

Comparing exception message strings is brittle; consider catching a more specific exception subclass or inspecting error attributes instead of matching on str(e).

Suggested change

	if str(e) == 'connection already closed':
	if getattr(e, 'args', None) and 'connection already closed' in e.args[0]:

[Copilot]

The try/except block wraps both worker and task handling, which may swallow unrelated errors. Consider narrowing the scope to only the database operations that need reconnection.

Suggested change

	try:
	for worker in state.workers.items():
	self.handle_worker(worker)
	_handle_tasks()
	except InterfaceError as e:
	# When connection already closed exception is raised,
	# force to close connection and Django will automatically reconnect
	if str(e) == 'connection already closed':
	connection.close()
	for worker in state.workers.items():
	self.handle_worker(worker)
	_handle_tasks()
	try:
	# Check and handle database reconnection if needed
	connection.close()
	except InterfaceError as e:
	# When connection already closed exception is raised,
	# force to close connection and Django will automatically reconnect
	if str(e) == 'connection already closed':