Companies/PyPI (Python Infrastructure)/Incidents

PyPI (Python Infrastructure): PyPI Partial Outage

Affected components: pypi.org - BackendsPyPI - pypi.org - Backends

Timeline of updates

1. investigating2025-05-24 22:57 UTC

   We are working to investigate a partial outage in the PyPI backends.

2. identified2025-05-24 23:11 UTC

   We have identified a large increase in CDN cache misses causing excess load on our backends. We are working to determine the reason for this increase.

3. identified2025-05-24 23:37 UTC

   We have identified a flood of requests from a cluster using the `python-requests/2.32.3` User-Agent, and attempting to hit all JSON project/releasese en masse. This causes excessive cache misses, which are overwhelming our backends. A temporary block has been put in place.

4. monitoring2025-05-24 23:54 UTC

   Our block is in place and systems are stable, but we are not satisfied with having to block such a generic user-agent. If you are aware of a system that began a mass crawl of PyPI's JSON release endpoints starting at around 22:05 UTC 2025-05-25, please contact admin@pypi.org.

5. monitoring2025-05-25 12:16 UTC

   We have removed the temporary block and are continuing to monitor.

6. resolved2025-05-27 12:53 UTC

   We have not seen a return of the traffic that caused this incident after removing the temporary block. We will open a new incident if we need to take action again.

Changes Rewindex caught on this incident

• May 24, 2025Major incident: PyPI Partial Outage

Impact, status and times are the vendor’s own, as last archived. View on stspg.io (opens in new tab).

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