Sep 4, 22:23 UTC
Resolved - On September 4, 2026, between approximately 21:45 and 22:07 UTC, some users experienced errors and elevated latency for repository operations. The incident was fully resolved at 22:23 UTC.
The cause was a capacity change that spread one of our clusters across additional availability zones; our zone-aware traffic routing kept sending requests to the original zone for performance, overloading a small set of servers while the new capacity sat idle. We resolved the incident by reverting the change and letting traffic rebalance.
We are improving per-zone capacity guarantees, cross-zone load-shedding, and pre-production testing of multi-zone changes to prevent recurrence.
Sep 4, 22:02 UTC
Investigating - We are investigating reports of impacted performance for some GitHub services.