DEV TOOLS Signal 641 2 feeds carried it
GitHub pull requests and issues returned 500 errors because a database migration removed an index referenced by a hint
↗
Illustration only Photo by JESHOOTS.COM on Unsplash
GitHub experienced 500 errors on pull requests, issues, and search because a recent database migration removed an index that was still referenced by a database index hint.
This incident highlights the risk of schema migrations that do not account for query hints or application-level dependencies on specific indexes. Engineers relying on GitHub for code review or issue tracking were blocked from loading these pages during the outage. It serves as a reminder that removing database indexes requires verifying that no active configurations depend on them.
Written by elseif from the cluster below · every claim links back to a sourceThe three things worth knowing
GitHub users encountered 500 errors when attempting to load pull requests, issues, and search pages.
The root cause was a database index hint referencing an index that a recent migration had removed.
GitHub mitigated the issue by disabling the problematic configuration and monitoring for stability.
THE CLUSTER