The Fix
pip install celery==4.4.0rc5
Based on closed celery/celery issue #4518 · PR/commit linked
Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.
@@ -36,7 +36,7 @@
from celery.utils.dispatch import Signal
from celery.utils.functional import first, maybe_list, head_from_fun
-from celery.utils.time import timezone
+from celery.utils.time import timezone, get_exponential_backoff_interval
from celery.utils.imports import gen_task_name, instantiate, symbol_by_name
Option A — Upgrade to fixed release\npip install celery==4.4.0rc5\nWhen NOT to use: Do not use this fix if your application cannot tolerate delays in task retries.\n\n
Why This Fix Works in Production
- Trigger: Tasks fail to store results in the database during downtime, leading to potential data loss.
- Mechanism: The default retry behavior in the database backend does not allow for configurable backoff strategies
- Why the fix works: Adds options for exponential backoff with task autoretry, allowing for more configurable retry strategies when tasks fail due to backend issues. (first fixed release: 4.4.0rc5).
- If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.
Why This Breaks in Prod
- The default retry behavior in the database backend does not allow for configurable backoff strategies
- Production symptom (often without a traceback): Tasks fail to store results in the database during downtime, leading to potential data loss.
Proof / Evidence
- GitHub issue: #4518
- Fix PR: https://github.com/celery/celery/pull/4101
- First fixed release: 4.4.0rc5
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.73
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“@MShekow this will be resolved by the exponential backoff feature that is already included in the master branch and will be available with the release…”
Failure Signature (Search String)
- Tasks fail to store results in the database during downtime, leading to potential data loss.
Copy-friendly signature
Failure Signature
-----------------
Tasks fail to store results in the database during downtime, leading to potential data loss.
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Tasks fail to store results in the database during downtime, leading to potential data loss.
What Broke
Tasks fail to store results in the database during downtime, leading to potential data loss.
Why It Broke
The default retry behavior in the database backend does not allow for configurable backoff strategies
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/4101
First fixed release: 4.4.0rc5
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- Do not use this fix if your application cannot tolerate delays in task retries.
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.