Release train coordinator
Ship Meridian updates on a predictable cadence with staged rollouts, canary channels, and automatic rollback triggers.
Overview
The release train runs every Tuesday at 10:00 UTC. Each train progresses through three gates — canary (5% of users), early-access (25%), and stable (100%). Gate promotion is automatic unless a circuit breaker fires.
Circuit breakers
- Crash rate exceeds 0.5% in any gate
- License check failure rate spikes above 2%
- CDN edge cache miss ratio jumps 3× baseline
Rollback
When a breaker trips, the coordinator pins the previous stable version and drains the affected gate within 60 seconds. On-call receives a Discord alert via the Meridian bot.
Artifacts
Each train produces a signed payload manifest, an Ed25519 signature bundle, and a versioned CDN prefix. The loader fetches the manifest on startup and validates the signature chain before pulling binaries.