**List of steps to reproduce** (step by step, including full links if applicable):
* Visit a production Wikimedia project
**What happens?**:
First, loading failed.
Then, 503 Service Unavailable
No server is available to handle this request.
At some point I also got:
Request from (IP redacted) via cp3062 cp3062, Varnish XID 204440230
Error: 503, Backend fetch failed at Sat, 21 May 2022 19:02:26 GMT
**What should have happened instead?**:
200
Phabricator was also affected. Beta cluster seemingly not. I tested different PoP locations per https://wikitech-static.wikimedia.org/wiki/Reporting_a_connectivity_issue but it made no difference.
Edit: sorry the 400 was due to a typo of mine. https://wikitech-static.wikimedia.org/wiki/Reporting_a_connectivity_issue uses www.wikimedia.org in its example but **that** was still working so I changed it and messed it up.