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redis-py KeyError: 'first-entry' in parse_xinfo_stream (Fix)

Fixed
Spec
Package
redis-py
Fixed In
7.1.0
Python
3.9
Verdict
Status
Fixed
Safe for prod
No
Risk
Medium
Last verified
2026-02-08
Own content ratio
0.34
#2768 ai concurrency retries Idempotency Violation Race Condition Updated: 2026-02-13
Issue #2768

The Fix

pip install redis==7.1.0

Based on closed redis/redis-py issue #2768 · 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
@@ -1,3 +1,4 @@ @@ -1,3 +1,4 @@ + * Fix #2768, Fix KeyError: 'first-entry' in parse_xinfo_stream. * Fix #2749, remove unnecessary __del__ logic to close connections. * Fix #2754, adding a missing argument to SentinelManagedConnection
repro.py
ERROR: Exception in ASGI application Traceback (most recent call last): .. fastapi stuff elided ... File "/serve.py", line 187, in fetch_key info = await r.xinfo_stream(key) File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 505, in execute_command return await conn.retry.call_with_retry( File "venv/lib/python3.9/site-packages/redis/asyncio/retry.py", line 59, in call_with_retry return await do() File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 481, in _send_command_parse_response return await self.parse_response(conn, command_name, **options) File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 536, in parse_response retval = self.response_callbacks[command_name](response, **options) File "venv/lib/python3.9/site-packages/redis/client.py", line 323, in parse_xinfo_stream first = data["first-entry"] KeyError: 'first-entry'
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 applied if the application relies on the strict presence of 'first-entry'.\n\n

Why This Fix Works in Production

  • Trigger: ERROR: Exception in ASGI application
  • Mechanism: The KeyError occurs due to the absence of 'first-entry' in the response data
  • Why the fix works: Fixes a KeyError that occurs in the parse_xinfo_stream function when accessing 'first-entry'. (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 3.9 in real deployments (not just unit tests).
  • The KeyError occurs due to the absence of 'first-entry' in the response data
  • Surfaces as: ERROR: Exception in ASGI application

Proof / Evidence

  • GitHub issue: #2768
  • Fix PR: https://github.com/redis/redis-py/pull/2788
  • 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: 0.34

Discussion

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

Jump to Sources Open on GitHub
“**Version**: redis-py 4.4.3, redis server 7.0.7 **Platform**: redis-py on various flavors of Linux (Debian and Ubuntu), redis server in AWS **Description**: Sometimes, I get this traceback: I haven't gotten it down to a reproducible test ca”
Issue thread · issue description · source

Failure Signature (Search String)

  • ERROR: Exception in ASGI application

Error Message

Stack trace
error.txt
Error Message ------------- ERROR: Exception in ASGI application Traceback (most recent call last): .. fastapi stuff elided ... File "/serve.py", line 187, in fetch_key info = await r.xinfo_stream(key) File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 505, in execute_command return await conn.retry.call_with_retry( File "venv/lib/python3.9/site-packages/redis/asyncio/retry.py", line 59, in call_with_retry return await do() File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 481, in _send_command_parse_response return await self.parse_response(conn, command_name, **options) File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 536, in parse_response retval = self.response_callbacks[command_name](response, **options) File "venv/lib/python3.9/site-packages/redis/client.py", line 323, in parse_xinfo_stream first = data["first-entry"] KeyError: 'first-entry'

Minimal Reproduction

repro.py
ERROR: Exception in ASGI application Traceback (most recent call last): .. fastapi stuff elided ... File "/serve.py", line 187, in fetch_key info = await r.xinfo_stream(key) File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 505, in execute_command return await conn.retry.call_with_retry( File "venv/lib/python3.9/site-packages/redis/asyncio/retry.py", line 59, in call_with_retry return await do() File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 481, in _send_command_parse_response return await self.parse_response(conn, command_name, **options) File "venv/lib/python3.9/site-packages/redis/asyncio/client.py", line 536, in parse_response retval = self.response_callbacks[command_name](response, **options) File "venv/lib/python3.9/site-packages/redis/client.py", line 323, in parse_xinfo_stream first = data["first-entry"] KeyError: 'first-entry'

Environment

  • Python: 3.9

What Broke

The application experiences intermittent failures when accessing stream information, leading to potential data access issues.

Why It Broke

The KeyError occurs due to the absence of 'first-entry' in the response data

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 applied if the application relies on the strict presence of 'first-entry'.

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/2788

First fixed release: 7.1.0

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

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When NOT to Use This Fix

  • This fix should not be applied if the application relies on the strict presence of 'first-entry'.

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

VersionStatus
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.

Source & Disclaimer: Analysis derived from GitHub Issue #2768. Not affiliated with the library maintainers. Verify before production use.