Disruption with GitHub's code search

Incident update

On April 1st, 2026 between 14:40 and 17:00 UTC the GitHub code search service had an outage which resulted in users being unable to perform searches.<br /><br />The issue was initially caused by an upgrade to the code search Kafka cluster ZooKeeper instances which caused a loss of quorum. This resulted in application-level data inconsistencies which required the index to be reset to a point in time before the loss of quorum occurred. Meanwhile, an accidental deploy resulted in query services losing their shard-to-host mappings, which are typically propagated by Kafka.<br /><br />We remediated the problem by performing rolling restarts in the Kafka cluster, allowing quorum to be reestablished. From there we were able to reset our index to a point in time before the inconsistencies occurred.<br /><br />The team is working on ways to improve our time to respond and mitigate issues relating to Kafka in the future.