A small checklist for Linux services

When a service is down, the first five minutes should be boring. A short checklist keeps the investigation grounded.

Check the unit

systemctl status my-service --no-pager -l

I look for the active state, recent log lines, restart loops, and the main process id.

Check the port

ss -lntup

This tells me whether the process is actually listening where clients expect it.

Check the local path

curl -v http://127.0.0.1:8080/

If local access fails, the issue is usually application configuration. If local works but remote fails, I look at firewall rules, DNS, TLS, or proxy configuration.