Connection refused

What it usually means

The host was reachable but actively refused the connection on that port. Usually the service is not running, or it is listening on a different port than the one configured here.

What to check first

• The web server or application process is running (a crash, an OOM kill, or a failed restart after a deploy).
• It listens on the port the monitor uses: 443 for https, 80 for http, or the custom port on a port monitor.
• A firewall or reverse proxy in front of the server is up; a stopped proxy refuses before the app is reached.

How ErrorDetector reports it

This is a reachability failure. The check is repeated immediately to rule out a blip; once confirmed, an incident opens with this cause on it, every channel on the monitor is alerted, and the outage counts against uptime until the next successful check closes the incident.

Caught by: httpkeywordapiport monitors. Read about the incident management feature.