GitHub's 7-Hour Outage Was Worsened by a VS Code Copilot Retry Loop

GitHub suffered a 7-hour, 47-minute outage on August 17, 2026, affecting Git operations, Actions, Issues, Pull Requests, and Copilot services. The incident began when an Istio sidecar proxy hit its concurrency limit, but GitHub's autoscaling failed to detect the overload since it monitored the host application rather than the proxy. A bug in the VS Code Copilot extension compounded the crisis by triggering aggressive client-side token re-requests, pushing the Copilot Token Service from its normal 7,000–9,000 requests per second to between 70,000 and 100,000. GitHub CTO Vlad Fedorov acknowledged that backend errors set off a client-side retry loop that amplified traffic precisely when the infrastructure was trying to recover. Engineers have since identified retry budgets and backoff with jitter as the key fixes to prevent unbounded retry storms from turning minor outages into prolonged incidents.