Celery Use bound task in base task example (Fix)

The Fix

pip install celery==5.3.0b2

Based on closed celery/celery issue #7909 · 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.

Jump to Verify Open PR/Commit

@@ -1432,9 +1432,11 @@ The above can be added to each task like this:
 
 
-    @app.task(base=DatabaseTask)
-    def process_rows():
-        for row in process_rows.db.table.all():

repro.py

from celery import Task

class DatabaseTask(Task):
    _db = None

    @property
    def db(self):
        if self._db is None:
            self._db = Database.connect()
        return self._db

@app.task(base=DatabaseTask)
def process_rows():
    for row in process_rows.db.table.all():
        process_row(row)

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==5.3.0b2\nWhen NOT to use: This fix is not applicable if the task does not require access to the bound instance.\n\n

Why This Fix Works in Production

Trigger: - [x] I have included all related issues and possible duplicate issues in this issue
Mechanism: Updates the documentation to use a bound task in the base task example, addressing issue #7909.
Why the fix works: Updates the documentation to use a bound task in the base task example, addressing issue #7909. (first fixed release: 5.3.0b2).

Production impact:

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

Production symptom (often without a traceback): - [x] I have included all related issues and possible duplicate issues in this issue

Proof / Evidence

GitHub issue: #7909
Fix PR: https://github.com/celery/celery/pull/7910
First fixed release: 5.3.0b2
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.57

Discussion

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

Jump to Sources Open on GitHub

“Hey @WilliamDEdwards :wave:, Thank you for opening an issue”

@open-collective-bot · 2022-11-16 · source

Failure Signature (Search String)

- [x] I have included all related issues and possible duplicate issues in this issue
or possible duplicates to this issue as requested by the checklist above.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
- [x] I have included all related issues and possible duplicate issues in this issue
or possible duplicates to this issue as requested by the checklist above.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
- [x] I have included all related issues and possible duplicate issues in this issue
or possible duplicates to this issue as requested by the checklist above.

Minimal Reproduction

repro.py

from celery import Task

class DatabaseTask(Task):
    _db = None

    @property
    def db(self):
        if self._db is None:
            self._db = Database.connect()
        return self._db

@app.task(base=DatabaseTask)
def process_rows():
    for row in process_rows.db.table.all():
        process_row(row)

What Broke

Tasks may fail to access the database connection in methods like after_return.

Fix Options (Details)

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

pip install celery==5.3.0b2

When NOT to use: This fix is not applicable if the task does not require access to the bound instance.

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/7910

First fixed release: 5.3.0b2

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

When NOT to Use This Fix

This fix is not applicable if the task does not require access to the bound instance.

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
5.3.0b2	Fixed

Related Issues

No related fixes found.

Cluster: celery:configuration-error Celery hub Celery best practices All hubs All clusters

Related clusters: Data consistency Duplicates Duplicate processing

Sources

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