Deploys and releases · 10 min read
Zero-downtime deploys on one VPS with Caddy and pm2
Run two copies of a Node app on two ports, health-check the new one, then switch Caddy to it. Commands, the pm2 symlink trap, and measured failed requests.
Posts tagged “zero-downtime”
7 articles about zero-downtime.
Deploys and releases · 9 min read
What a plain systemctl restart costs a Go service under load
We sent 20 requests per second through Caddy while restarting a Go service. About one in four failed. Measure your own restart, then pick a fix that fits.
Deploys and releases · 9 min read
systemd socket activation: no dropped requests, but a cost
Socket activation let a Go service restart without refusing a connection, but slow requests waited over five seconds. Setup, code, and when to use it.
Deploys and releases · 9 min read
Roll back a bad deploy in a minute with release folders
Keep each release in its own directory behind a current symlink, switch atomically, prune old ones, and roll back with one command, including the database caveat.
Deploys and releases · 10 min read
Database migrations that survive a zero-downtime deploy
Use expand and contract to change a SQLite or Postgres schema while two releases overlap, with the lock pitfalls and the safe forms of common changes.
Deploys and releases · 10 min read
Deploy health checks that catch bad releases
Design a health endpoint and a deploy gate that reject broken releases, with readiness versus liveness, consecutive passes, and the false greens to avoid.
Deploys and releases · 10 min read
Caddy blue/green config for a one-server app, line by line
Switch a Caddy 2 reverse proxy between two upstream ports with a generated snippet and a graceful reload, with health checks and retry settings explained.