Incident Library

Organisation

PostHog

PostHog · posthog

1 case · 2025

Root cause Capacity exhaustion

Component In-memory cache Application database Node pool Pod scheduling and placement

Contributing factor No alert on limit No staged rollout Retry storm Ineffective rollback Single point of failure Unrepresentative staging

Symptom Container crash loop Database overload High error rate High latency Sustained high node CPU

Cases

IL-0100 PostHog's feature flags pods were packed onto Kubernetes nodes that were too small for their CPU requests, and CPU saturation above 90% caused three outages in ten days through Redis overload, connection pool exhaustion and slow queriesPostHog · 2025
Root cause Capacity exhaustion