Celery task.request.hostname no longer contains worker node

The Fix

pip install celery==5.1.0b1

Based on closed celery/celery issue #6555 · 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

@@ -302,6 +302,10 @@ def __init__(self, main=None, loader=None, backend=None,
         self.on_after_fork = Signal(name='app.on_after_fork')
 
+        # Boolean signalling, whether fast_trace_task are enabled.
+        # this attribute is set in celery.worker.trace and checked by celery.worker.request
+        self.use_fast_trace_task = False

repro.py

from celery import Celery

app = Celery(broker='redis://localhost:6379/0', backend='redis://localhost:6379/0')

@app.task(bind=True)
def worker_name(self):
    return self.request.hostname

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==5.1.0b1\nWhen NOT to use: This fix should not be applied if the global state change is required for other functionalities.\n\n

Why This Fix Works in Production

Trigger: - [x] I have included all related issues and possible duplicate issues
Mechanism: Changes the setting of trace optimization from a global module state change to marking it as a Celery object state.
Why the fix works: Changes the setting of trace optimization from a global module state change to marking it as a Celery object state. (first fixed release: 5.1.0b1).

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

Proof / Evidence

GitHub issue: #6555
Fix PR: https://github.com/celery/celery/pull/6598
First fixed release: 5.1.0b1
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.62

Discussion

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

Jump to Sources Open on GitHub

“Hi! Yes I can confirm that #6598 solves this problem for me! :)”

@freedrikp · 2021-02-11 · source

“Yes, all 4.x.x versions follow the documentation and works as I would expect. The bug was introduced in 5.0.0 and since then it no longer…”

@freedrikp · 2020-12-22 · source

“> I have managed to bisect the issue to: > > @thedrow mind having a look?”

@auvipy · 2020-12-29 · source

“OK I was able to fix the issue (this is only dirty not complete fix). Basically, instead of dirty rewriting globals of modules, I have…”

@matusvalo · 2021-01-02 · source

Failure Signature (Search String)

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

Minimal Reproduction

repro.py

from celery import Celery

app = Celery(broker='redis://localhost:6379/0', backend='redis://localhost:6379/0')

@app.task(bind=True)
def worker_name(self):
    return self.request.hostname

What Broke

Tasks were unable to correctly identify the worker node name, leading to confusion in task routing.

Fix Options (Details)

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

pip install celery==5.1.0b1

When NOT to use: This fix should not be applied if the global state change is required for other functionalities.

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/6598

First fixed release: 5.1.0b1

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

When NOT to Use This Fix

This fix should not be applied if the global state change is required for other functionalities.

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
5.1.0b1	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.

Celery task.request.hostname no longer contains worker node name but only the hostname (Fix)