We are investigating a rise in request failures on several services

Final update

Between 13:25 UTC and 18:35 UTC on December 11th, GitHub experienced elevated traffic to portions of GitHub.com that exceeded previously provisioned capacity for specific request types. As a result, users encountered intermittent 500 errors. Impact was most pronounced on Login, Logout, and Signup pages, peaking at 7.6% of login requests. Additionally, fewer than 1% of requests originating from GitHub Actions jobs were affected. This incident was driven by the same underlying factors as the previously reported disruption to Login and Signup flows Our immediate response focused on identifying and mitigating the source of the traffic increase. We increased available capacity for web request handling to relieve pressure on constrained pools. To reduce recurrence risk, we also re-routed critical authentication endpoints to a different traffic pool, ensuring sufficient isolation and headroom for login related traffic. In future, we’re working to more proactively identify these large changes in traffic volume and improve our time to mitigation.

1. Resolved · Dec 11, 17:53 UTC
   Between 13:25 UTC and 18:35 UTC on December 11th, GitHub experienced elevated traffic to portions of GitHub.com that exceeded previously provisioned capacity for specific request types. As a result, users encountered intermittent 500 errors. Impact was most pronounced on Login, Logout, and Signup pages, peaking at 7.6% of login requests. Additionally, fewer than 1% of requests originating from GitHub Actions jobs were affected. This incident was driven by the same underlying factors as the previously reported disruption to Login and Signup flows Our immediate response focused on identifying and mitigating the source of the traffic increase. We increased available capacity for web request handling to relieve pressure on constrained pools. To reduce recurrence risk, we also re-routed critical authentication endpoints to a different traffic pool, ensuring sufficient isolation and headroom for login related traffic. In future, we’re working to more proactively identify these large changes in traffic volume and improve our time to mitigation.