redis-py Lock.acquire() interface change with 4.3.2 (Fix)

The Fix

pip install redis==7.1.0

Based on closed redis/redis-py issue #2218 · 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%.

Jump to Verify Open PR/Commit

@@ -169,7 +169,6 @@ def __exit__(
     def acquire(
         self,
-        *,
         sleep: Optional[Number] = None,
         blocking: Optional[bool] = None,

repro.py

import redis
client = redis.Redis()
lock = client.lock('lockName')
if lock.acquire(False):
    print("lock acquired!")
    lock.release()

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 should not be used if the application relies on the old positional argument behavior.\n\n

Why This Fix Works in Production

Trigger: Lock.acquire() interface change with 4.3.2
Mechanism: Fixes backward compatibility issues introduced in versions 4.3.2 and 4.3.3 regarding the Lock.acquire() method.
Why the fix works: Fixes backward compatibility issues introduced in versions 4.3.2 and 4.3.3 regarding the Lock.acquire() method. (first fixed release: 7.1.0).

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

Shows up under Python 3.7.15 in real deployments (not just unit tests).
Production symptom (often without a traceback): Lock.acquire() interface change with 4.3.2

Proof / Evidence

GitHub issue: #2218
Fix PR: https://github.com/redis/redis-py/pull/2254
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: 0.65

Discussion

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

Jump to Sources Open on GitHub

“After submit, also referenced here: https://github.com/redis/redis-py/issues/2209#issuecomment-1145983577”

@timhanus · 2022-06-06 · source

Failure Signature (Search String)

Lock.acquire() interface change with 4.3.2
In versions 4.3.2 and 4.3.3 the `lock.acquire(False)` gives `TypeError: acquire() takes 1 positional argument but 2 were given` and forces us to use the `blocking=` keyword

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Lock.acquire() interface change with 4.3.2
In versions 4.3.2 and 4.3.3 the `lock.acquire(False)` gives `TypeError: acquire() takes 1 positional argument but 2 were given`  and forces us to use the `blocking=` keyword arguments.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Lock.acquire() interface change with 4.3.2
In versions 4.3.2 and 4.3.3 the `lock.acquire(False)` gives `TypeError: acquire() takes 1 positional argument but 2 were given`  and forces us to use the `blocking=` keyword arguments.

Minimal Reproduction

repro.py

import redis
client = redis.Redis()
lock = client.lock('lockName')
if lock.acquire(False):
    print("lock acquired!")
    lock.release()

Environment

Python: 3.7.15

What Broke

TypeErrors occurred during non-blocking lock acquisition, causing application failures.

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 relies on the old positional argument behavior.

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/2254

First fixed release: 7.1.0

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

When NOT to Use This Fix

This fix should not be used if the application relies on the old positional argument behavior.

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: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.