redis-py Unrecoverable connection state where parser raises

The Fix

pip install redis==7.1.1

Based on closed redis/redis-py issue #3904 · 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%.

Open PR/Commit

@@ -35,7 +35,6 @@
     OutOfMemoryError,
     ReadOnlyError,
-    RedisError,
     ResponseError,
     TryAgainError,

fix.md

Option A — Upgrade to fixed release\npip install redis==7.1.1\nWhen NOT to use: Do not use this fix if the connection state is not properly validated before operations.\n\n

Why This Fix Works in Production

Trigger: Unrecoverable connection state where parser raises `RedisError("Buffer is closed.")`
Mechanism: The connection state is inconsistent due to unhandled RedisError when the parser's buffer is closed
Why the fix works: Fixes an unrecoverable connection state in async Redis connections where the parser raises a RedisError due to a closed buffer. (first fixed release: 7.1.1).

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

The connection state is inconsistent due to unhandled RedisError when the parser's buffer is closed
Surfaces as: Unrecoverable connection state where parser raises `RedisError("Buffer is closed.")`

Proof / Evidence

GitHub issue: #3904
Fix PR: https://github.com/redis/redis-py/pull/3905
First fixed release: 7.1.1
Reproduced locally: No (not executed)
Last verified: 2026-02-08
Confidence: 0.70
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

“Hi @itssimon, thank you for reporting this! We will have a look at it.”

@petyaslavova · 2026-01-06 · source

Failure Signature (Search String)

Unrecoverable connection state where parser raises `RedisError("Buffer is closed.")`

Error Message

Stack trace

error.txt

Error Message
-------------
Unrecoverable connection state where parser raises `RedisError("Buffer is closed.")`

What Broke

Every operation fails with RedisError, leading to a non-recoverable connection state.

Why It Broke

The connection state is inconsistent due to unhandled RedisError when the parser's buffer is closed

Fix Options (Details)

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

pip install redis==7.1.1

When NOT to use: Do not use this fix if the connection state is not properly validated before operations.

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/3905

First fixed release: 7.1.1

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

When NOT to Use This Fix

Do not use this fix if the connection state is not properly validated before operations.

Did This Fix Work in Your Case?

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

Prevention

Track RSS + object counts after deployments; alert on monotonic growth and GC pressure.
Add a long-running test that repeats the failing call path and asserts stable memory.
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
7.1.1	Fixed

Related Issues

No related fixes found.

Cluster: redis-py:configuration-error redis-py hub redis-py best practices All hubs All clusters

Related clusters: Retry storm Data consistency Race condition

Sources

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

redis-py Unrecoverable connection state where parser raises `RedisError("Buffer is closed.")` (Fix)