redis-py Reconnect to redis if got ReadOnlyError

The Fix

pip install redis==7.1.0

Based on closed redis/redis-py issue #935 · 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.

Open PR/Commit

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+from abc import ABC, abstractmethod
+import random
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fix.md

Option A — Upgrade to fixed release\npip install redis==7.1.0\nWhen NOT to use: This fix should not be used if the application requires strict read/write separation.\n\n

Why This Fix Works in Production

Trigger: Reconnect to redis if got ReadOnlyError | sentinel
Mechanism: The Redis client does not handle ReadOnlyError during master-slave failover properly
Why the fix works: Adds a retry mechanism with backoff to handle ReadOnlyError in Redis commands. (first fixed release: 7.1.0).

Production impact:

If left unfixed, retry loops can amplify load and turn a small outage into a cascade (thundering herd).

Why This Breaks in Prod

The Redis client does not handle ReadOnlyError during master-slave failover properly
Surfaces as: Reconnect to redis if got ReadOnlyError | sentinel

Proof / Evidence

GitHub issue: #935
Fix PR: https://github.com/redis/redis-py/pull/1494
First fixed release: 7.1.0
Reproduced locally: No (not executed)
Last verified: 2026-02-08
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.86

Discussion

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

Jump to Sources Open on GitHub

“This issue is marked stale. It will be closed in 30 days if it is not updated.”

@github-actions · 2020-06-30 · source

“Not only about the use of sentinel, for example during failover process, the master node will also changes to replica, and if you use DNS…”

@axot · 2022-02-10 · source

Failure Signature (Search String)

Reconnect to redis if got ReadOnlyError | sentinel

Error Message

Stack trace

error.txt

Error Message
-------------
Reconnect to redis if got ReadOnlyError | sentinel

What Broke

Clients experience ReadOnlyError when attempting to write to a replica during failover.

Why It Broke

The Redis client does not handle ReadOnlyError during master-slave failover properly

Fix Options (Details)

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

pip install redis==7.1.0

When NOT to use: This fix should not be used if the application requires strict read/write separation.

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

Fix reference: https://github.com/redis/redis-py/pull/1494

First fixed release: 7.1.0

Last verified: 2026-02-08. Validate in your environment.

When NOT to Use This Fix

This fix should not be used if the application requires strict read/write separation.

Did This Fix Work in Your Case?

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

Prevention

Make timeouts explicit and test them (unit + integration) to avoid silent behavior changes.
Instrument retries (attempt count + reason) and alert on spikes to catch dependency slowdowns.

Version Compatibility Table

Version	Status
7.1.0	Fixed

Related Issues

No related fixes found.

Cluster: redis-py:retry-storm redis-py hub redis-py best practices All hubs All clusters

Related clusters: Configuration error Data consistency Race condition

Sources

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

redis-py Reconnect to redis if got ReadOnlyError | sentinel (Fix)