The Fix
pip install celery==4.4.0rc5
Based on closed celery/celery issue #5436 · PR/commit linked
Production note: This usually shows up under retries/timeouts. Treat it as a side-effect risk until you can verify behavior with a canary + real traffic.
@@ -351,6 +351,54 @@ def encode_result(self, result, state):
return task_id in self._cache
+ def _get_result_meta(self, result,
+ state, traceback, request, format_date=True,
+ encode=False):
celery -A celeryacl report
software -> celery:4.3.0 (rhubarb) kombu:4.5.0 py:3.6.8
billiard:3.6.0.0 py-amqp:2.4.2
platform -> system:Linux arch:64bit
kernel version:4.18.0-1013-azure imp:CPython
loader -> celery.loaders.app.AppLoader
settings -> transport:amqp results:db+mysql+pymysql://celery:**@X.X.X.X:XXXX/celeryresults
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
Option A — Upgrade to fixed release\npip install celery==4.4.0rc5\nWhen NOT to use: This fix should not be applied if using a backend that requires specific handling for extended results.\n\n
Why This Fix Works in Production
- Trigger: Celery 4.3 result_extended doesn't push extended meta data to some backends when set to true
- Mechanism: The result_extended flag does not propagate extended metadata to all backends
- Why the fix works: Fixes issue #5436 by ensuring that extended result metadata is stored in all backends except Cassandra. (first fixed release: 4.4.0rc5).
- If left unfixed, this can cause silent data inconsistencies that propagate (bad cache entries, incorrect downstream decisions).
Why This Breaks in Prod
- The result_extended flag does not propagate extended metadata to all backends
- Production symptom (often without a traceback): Celery 4.3 result_extended doesn't push extended meta data to some backends when set to true
Proof / Evidence
- GitHub issue: #5436
- Fix PR: https://github.com/celery/celery/pull/5661
- First fixed release: 4.4.0rc5
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.75
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.60
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“I wrote the original PR, and didn't scope it to the other backends other than KV (redis for my use case)”
“As referenced here: http://docs.celeryproject.org/en/latest/whatsnew-4.3.html#result-backends it doesn't state that any additional configuration is needed but perhaps I am missing something.”
“> > > @mikolevy Thanks for the accurate analysis. We overlooked those. > > This should be a very easy fix. > Any volunteers for…”
“@thedrow do I need contributor rights to create the branch with the fix? Also do you have some rules or guidelines on how to name…”
Failure Signature (Search String)
- Celery 4.3 result_extended doesn't push extended meta data to some backends when set to true
- - [x] I have included all related issues and possible duplicate issues
Copy-friendly signature
Failure Signature
-----------------
Celery 4.3 result_extended doesn't push extended meta data to some backends when set to true
- [x] I have included all related issues and possible duplicate issues
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Celery 4.3 result_extended doesn't push extended meta data to some backends when set to true
- [x] I have included all related issues and possible duplicate issues
Minimal Reproduction
celery -A celeryacl report
software -> celery:4.3.0 (rhubarb) kombu:4.5.0 py:3.6.8
billiard:3.6.0.0 py-amqp:2.4.2
platform -> system:Linux arch:64bit
kernel version:4.18.0-1013-azure imp:CPython
loader -> celery.loaders.app.AppLoader
settings -> transport:amqp results:db+mysql+pymysql://celery:**@X.X.X.X:XXXX/celeryresults
What Broke
Extended metadata is missing from task results in some backends, leading to incomplete task information.
Why It Broke
The result_extended flag does not propagate extended metadata to all backends
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install celery==4.4.0rc5
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/5661
First fixed release: 4.4.0rc5
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix should not be applied if using a backend that requires specific handling for extended results.
Verify Fix
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.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.