GitHub’s anonymous traffic surge broke CI for three hours
A surge in anonymous requests to GitHub.com returned 504 Gateway Timeout errors for about three hours on 9 November, breaking CI jobs and release downloads that do not authenticate. GitHub has not published a root cause.
GitHub had a roughly three-hour incident on 9 November, caused by a surge in anonymous traffic. Starting at 05:59 UTC, unauthenticated requests to GitHub.com began returning 504 Gateway Timeout errors, while logged-in users saw no disruption. GitHub’s status page flagged CI jobs and release downloads as the parts most likely to break, since both routinely hit GitHub without a token.
GitHub reported the degradation mitigated at 06:51 UTC, then again at 09:05 after error rates crept back up, before marking the incident resolved at 09:09. No root cause has been published yet; GitHub says a detailed analysis is coming.
Why it matters: if your CI pipeline or install script pulls from GitHub anonymously, downloading a release tarball or cloning a public repo without a token, you were exposed to this in a way authenticated traffic wasn’t. Logged-in and authenticated requests rode through the whole incident unaffected, which is a reasonable argument for authenticating even low-stakes CI requests with a scoped token.
The caveat: GitHub hasn’t said what caused the traffic surge, so there’s no guarantee it won’t happen again before whatever fix comes out of the root cause analysis.