Celery Results backend has minimal data (Fix)

The Fix

pip install celery==4.4.0rc5

Based on closed celery/celery issue #4309 · PR/commit linked

Jump to Verify Open PR/Commit

@@ -180,6 +180,7 @@ def __repr__(self):
         ),
         persistent=Option(None, type='bool'),
+        extended=Option(False, type='bool'),
         serializer=Option('json'),
         backend_transport_options=Option({}, type='dict'),

repro.py

from datetime import datetime

from celery import Celery
from celery.backends.redis import RedisBackend
from celery.result import AsyncResult
from kombu.utils.encoding import bytes_to_str
from kombu.utils.objects import cached_property
from tzlocal import get_localzone


class ExtendedCelery(Celery):
    @cached_property
    def AsyncResult(self):  # noqa: N802
        """
        Override the default result class of Celery
        """
        return self.subclass_with_self('path.to.your.module:ExtendedAsyncResult')


class ExtendedRedisBackend(RedisBackend):
    def _store_result(self, task_id, result, state,
                      traceback=None, request=None, **kwargs):

        if state in self.READY_STATES:
            date_done = datetime.now(get_localzone()).isoformat()
        else:
            date_done = None

        meta = {
            'status': state,
            'result': result,
            'traceback': traceback,
            'children': self.current_task_children(request),
            'task_id': bytes_to_str(task_id),
            'task': request.task,
            'date_done': date_done,
        }
        self.set(self.get_key_for_task(task_id), self.encode(meta))
        return result


class ExtendedAsyncResult(AsyncResult):
    @property
    def task(self):
        return self._get_task_meta().get('task')

    @property
    def date_done(self):
        return self._get_task_meta().get('date_done')

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\npip install celery==4.4.0rc5\nWhen NOT to use: This fix is not suitable if minimal metadata is desired for performance reasons.\n\n

Why This Fix Works in Production

Trigger: 'traceback': traceback,
Mechanism: The results backend does not store sufficient metadata about task execution
Why the fix works: Extends AsyncResult and Backend to store additional properties of task execution in the results backend. (first fixed release: 4.4.0rc5).

Production impact:

If left unfixed, this can cause silent data inconsistencies that propagate (bad cache entries, incorrect downstream decisions).

Why This Breaks in Prod

The results backend does not store sufficient metadata about task execution
Production symptom (often without a traceback): 'traceback': traceback,

Proof / Evidence

GitHub issue: #4309
Fix PR: https://github.com/celery/celery/pull/4490
First fixed release: 4.4.0rc5
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.70
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.36

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“We subclassed some Celery classes to have more info in our redis result backend. More particularly the name of the task and when it finished.…”

@jobec · 2017-10-04 · source

“Other than a bit of backend storage space, is there a good reason NOT to include all the task "event" metadata by default? The thing…”

@johnarnold · 2017-10-10 · source

“is it issue of celery or flower? or both?”

@auvipy · 2017-12-20 · source

“@auvipy This issue is specifically for celery”

@johnarnold · 2018-01-03 · source

Failure Signature (Search String)

'traceback': traceback,
Are there any comments on generally changing celery to store the same metadata that it sends out in events?

Copy-friendly signature

signature.txt

Failure Signature
-----------------
'traceback': traceback,
Are there any comments on generally changing celery to store the same metadata that it sends out in events?

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
'traceback': traceback,
Are there any comments on generally changing celery to store the same metadata that it sends out in events?

Minimal Reproduction

repro.py

from datetime import datetime

from celery import Celery
from celery.backends.redis import RedisBackend
from celery.result import AsyncResult
from kombu.utils.encoding import bytes_to_str
from kombu.utils.objects import cached_property
from tzlocal import get_localzone


class ExtendedCelery(Celery):
    @cached_property
    def AsyncResult(self):  # noqa: N802
        """
        Override the default result class of Celery
        """
        return self.subclass_with_self('path.to.your.module:ExtendedAsyncResult')


class ExtendedRedisBackend(RedisBackend):
    def _store_result(self, task_id, result, state,
                      traceback=None, request=None, **kwargs):

        if state in self.READY_STATES:
            date_done = datetime.now(get_localzone()).isoformat()
        else:
            date_done = None

        meta = {
            'status': state,
            'result': result,
            'traceback': traceback,
            'children': self.current_task_children(request),
            'task_id': bytes_to_str(task_id),
            'task': request.task,
            'date_done': date_done,
        }
        self.set(self.get_key_for_task(task_id), self.encode(meta))
        return result


class ExtendedAsyncResult(AsyncResult):
    @property
    def task(self):
        return self._get_task_meta().get('task')

    @property
    def date_done(self):
        return self._get_task_meta().get('date_done')

What Broke

Inconsistent task state information leads to unreliable task tracking in Flower.

Why It Broke

The results backend does not store sufficient metadata about task execution

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

pip install celery==4.4.0rc5

When NOT to use: This fix is not suitable if minimal metadata is desired for performance reasons.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Fix reference: https://github.com/celery/celery/pull/4490

First fixed release: 4.4.0rc5

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

This fix is not suitable if minimal metadata is desired for performance reasons.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
Pin production dependencies and upgrade only with a reproducible test that hits the failing path.

Version Compatibility Table

Version	Status
4.4.0rc5	Fixed

Related Issues

No related fixes found.

Cluster: celery:data-consistency Celery hub Celery best practices All hubs All clusters

Related clusters: Configuration error Duplicates Duplicate processing

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.