GitHub search is degraded
This summary is created by Generative AI and may differ from the actual content.
Overview
GitHub search services experienced degraded connectivity due to saturation of the load‑balancing tier in front of the search infrastructure, causing intermittent failures for multiple GitHub features between 16:15 UTC and 22:46 UTC on 27 April 2026.
Impact
Up to 65 % of search requests timed out or returned errors, affecting Issues, Pull Requests, Projects, Repositories, Actions, Package Registry and Dependabot Alerts. The degradation was most severe between 16:15 UTC and 18:00 UTC. No specific revenue impact was reported in the source document.
Trigger
A large influx of anonymous, distributed scraping traffic that was crafted to evade public API rate limits. This traffic accounted for ~30 % of the day’s total search traffic, was concentrated in a four‑hour window, and originated from over 600,000 unique IP addresses.
Detection
Continuous monitoring observed a drop in search results and rising error rates. The incident was declared at 16:21 UTC when the issues were determined not to be self‑healing.
Resolution
Mitigations focused on relieving pressure from the load balancers, scaling the load‑balancing tier, blocking the anomalous scraping traffic, and applying tuning to the balancers. The source of the excess load was disabled, connection handling was optimized, and new monitors and controls were added to restrict anonymous traffic.
Root Cause
Saturation of the load‑balancing tier caused by an unexpected surge of anonymous scraping traffic that bypassed API rate limits, overwhelming the search infrastructure.