redis-py redis.asyncio trying to reuse a closed connection

The Fix

pip install redis==7.1.0

Based on closed redis/redis-py issue #2065 · PR/commit linked

Production note: This tends to surface only under concurrency. Reproduce with load tests and watch for lock contention/cancellation paths.

Jump to Verify Open PR/Commit

@@ -6,6 +6,7 @@
     * Fix scan_iter for RedisCluster
     * Remove verbose logging when initializing ClusterPubSub, ClusterPipeline or RedisCluster
+    * Fix broken connection writer lock-up for asyncio (#2065)
 
 * 4.1.3 (Feb 8, 2022)

repro.py

import asyncio
from fastapi import FastAPI
from fastapi.responses import HTMLResponse, StreamingResponse
from redis import asyncio as aioredis

app = FastAPI()
red = aioredis.from_url('redis://redisedge:6379')

with open('data/random.jpg', 'rb') as f:
    placeholder_image = f.read()

@app.get('/')
def index():
    return HTMLResponse('<img src="/video" width="600" height="400" />')

@app.get('/push')
async def add_image():
    return await red.xadd('camera:bug-test', { 'image': placeholder_image })

@app.get('/video')
def video_feed(name='camera:bug-test',field='image'):
    async def stream():
        while True:
            # query image
            p = red.pipeline(transaction=True).xrevrange(name, count=1)
            print('before execute')
            cmsg, = await p.execute()  # hangs here forever
            print('after execute', len(cmsg))

            # serve image
            if not cmsg:
                break
            yield format_frame(cmsg[0][1][field.encode('utf-8')])
            await asyncio.sleep(0.01)

    return StreamingResponse(stream(), media_type='multipart/x-mixed-replace; boundary=frame')


def format_frame(frame):
    return (
        b'--frame\r\n'
        b'Pragma-directive: no-cache\r\n'
        b'Cache-directive: no-cache\r\n'
        b'Cache-control: no-cache\r\n'
        b'Pragma: no-cache\r\n'
        b'Expires: 0\r\n'
        b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n\r\n')

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 redis==7.1.0\nWhen NOT to use: This fix is not applicable if the connection handling logic is fundamentally altered.\n\n

Why This Fix Works in Production

Trigger: RuntimeError: unable to perform operation on <TCPTransport closed=True reading=False>; the handler is closed
Mechanism: A race condition occurs when closing a StreamWriter, leading to attempts to reuse a closed writer
Why the fix works: Fixes a race condition that causes broken connections in redis.asyncio by ensuring that closed writers are properly discarded. (first fixed release: 7.1.0).

Production impact:

If left unfixed, failures can be intermittent under concurrency (hard to reproduce; shows up as sporadic 5xx/timeouts).

Why This Breaks in Prod

Shows up under Python 3.7.12 in real deployments (not just unit tests).
A race condition occurs when closing a StreamWriter, leading to attempts to reuse a closed writer
Surfaces as: RuntimeError: unable to perform operation on <TCPTransport closed=True reading=False>; the handler is closed

Proof / Evidence

GitHub issue: #2065
Fix PR: https://github.com/redis/redis-py/pull/2077
First fixed release: 7.1.0
Reproduced locally: No (not executed)
Last verified: 2026-02-07
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.41

Discussion

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

Jump to Sources Open on GitHub

“**Version**: 4.2.0 (only version with asyncio) **Platform**: Mac / Docker / Python 3.7.12 > My code builds off of this repo, but the code in the repo isn't relevant for the minimum code sample. I'm just using it to provide the redis instanc”

Issue thread · issue description · source

Failure Signature (Search String)

RuntimeError: unable to perform operation on <TCPTransport closed=True reading=False>; the handler is closed

Error Message

Stack trace

error.txt

Error Message
-------------
RuntimeError: unable to perform operation on <TCPTransport closed=True reading=False>; the handler is closed

Minimal Reproduction

repro.py

import asyncio
from fastapi import FastAPI
from fastapi.responses import HTMLResponse, StreamingResponse
from redis import asyncio as aioredis

app = FastAPI()
red = aioredis.from_url('redis://redisedge:6379')

with open('data/random.jpg', 'rb') as f:
    placeholder_image = f.read()

@app.get('/')
def index():
    return HTMLResponse('<img src="/video" width="600" height="400" />')

@app.get('/push')
async def add_image():
    return await red.xadd('camera:bug-test', { 'image': placeholder_image })

@app.get('/video')
def video_feed(name='camera:bug-test',field='image'):
    async def stream():
        while True:
            # query image
            p = red.pipeline(transaction=True).xrevrange(name, count=1)
            print('before execute')
            cmsg, = await p.execute()  # hangs here forever
            print('after execute', len(cmsg))

            # serve image
            if not cmsg:
                break
            yield format_frame(cmsg[0][1][field.encode('utf-8')])
            await asyncio.sleep(0.01)

    return StreamingResponse(stream(), media_type='multipart/x-mixed-replace; boundary=frame')


def format_frame(frame):
    return (
        b'--frame\r\n'
        b'Pragma-directive: no-cache\r\n'
        b'Cache-directive: no-cache\r\n'
        b'Cache-control: no-cache\r\n'
        b'Pragma: no-cache\r\n'
        b'Expires: 0\r\n'
        b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n\r\n')

Environment

Python: 3.7.12

What Broke

Redis calls hang indefinitely after refreshing the page multiple times, causing service disruption.

Why It Broke

A race condition occurs when closing a StreamWriter, leading to attempts to reuse a closed writer

Fix Options (Details)

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

pip install redis==7.1.0

When NOT to use: This fix is not applicable if the connection handling logic is fundamentally altered.

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/2077

First fixed release: 7.1.0

Last verified: 2026-02-07. Validate in your environment.

When NOT to Use This Fix

This fix is not applicable if the connection handling logic is fundamentally altered.

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

Add a stress test that runs high-concurrency workloads and fails on thread dumps / blocked locks.
Enable watchdog dumps in prod (faulthandler, thread dump endpoint) to capture deadlocks quickly.

Version Compatibility Table

Version	Status
7.1.0	Fixed

Related Issues

No related fixes found.

Cluster: redis-py:race-condition redis-py hub redis-py best practices All hubs All clusters

Related clusters: Configuration error Retry storm Data consistency

Sources

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

redis-py redis.asyncio trying to reuse a closed connection writer (Fix)