This summary is created by Generative AI and may differ from the actual content.
Overview
On August 21, 2025, from approximately 15:37 UTC to 18:10 UTC, GitHub Actions experienced increased delays and failures when starting jobs on standard hosted runners due to connectivity issues in the East US region, leading to reduced capacity, job queuing, and service interruptions.Impact
Approximately 8.05% of jobs on public standard Ubuntu24 runners and 3.4% of jobs on private standard Ubuntu24 runners did not start as expected, causing increased delays and failures for customers.Trigger
The incident was triggered by connectivity issues in the East US region.Detection
The incident was detected through reports of degraded performance for Actions and slow queue times for Hosted Runners.Resolution
The issue was mitigated by provisioning additional resources in the affected region and burning down the backlog of queued runner assignments by 18:10 UTC. Subsequently, changes were deployed to improve runner connectivity resilience and graceful degradation. Further steps are planned to enhance observability of network connection health, improve load distribution, and failover handling.Root Cause
The root cause was connectivity issues in the East US region, which prevented runners from retrieving jobs and sending progress updates, resulting in significantly reduced capacity for GitHub Actions.