Incident with CodeQL
This summary is created by Generative AI and may differ from the actual content.
Overview
On May 13, 2026, the Code Scanning service experienced processing delays from 14:31 to 16:03 UTC, with 12% of check runs taking over 15 minutes due to replication lag from an internal database migration, which was mitigated by scaling workers.
Impact
Processing delays affected Code Scanning results; 12% of check runs exceeded 15 minutes, lasting about 1.5 hours.
Trigger
Replication lag caused by an internal database migration that reduced worker capacity.
Detection
The team became aware through reports of degraded performance and monitoring alerts indicating delayed or incomplete CodeQL scanning results.
Resolution
Scaled processing workers by 34%, making the capacity increase permanent, and continued monitoring until normal processing times were restored.
Root Cause
Insufficient worker capacity due to replication lag from the internal database migration, which could not keep up with the high rate of job enqueues.