Last updated: 30 JUN 2018 by @seanvree

• Monitorr is compatible with any service that is assigned a static IP address/host AND is listening on a user-defined static port. This also includes, but is NOT limited to, web applications that are served from a "base-URL" and/or "sub-path" ie, http://mydomain.com:80/application or http://application.mydomain.com:80 .

• Monitorr uses CURL to receive HTTP status codes from a specified service in order to determine UP/DOWN status. Monitorr also uses a fallback method similar to a PING function (fsockopen) to check if any response is received on the given port. CURL is a bit more advanced than a simple ping as Curl actually checks to see if the service is serving a valid webpage whereas fsockopen simply checks to see if there is ANY response at the given address. However, Monitorr can be configured to monitor a service which does not serve a webpage, but only listens on a given port. Services which serve a webpage (NGINX, IIS, PLEX, Netdata, etc) should be configured for "Standard" and all others (Db applications, IoT devices, PCs, etc) should be set to "Ping Only". Please see the "Monitorr Settings" section of this Wiki for further explanation: https://github.com/Monitorr/Monitorr/wiki/03-Monitorr-Settings

• If a service is configured with the default setting of “Standard” Check Type in the "Services Configuration" settings page, Monitorr will use Curl as the primary check and automatically fallback to fsockopen if Curl fails. Below are the Monitorr status responses if the given service is configured for “Standard”:

ONLINE: Curl valid response code received.

UNRESPONSIVE: Curl Invalid/absent HTTP code received, PING response received.

OFFLINE: Curl Invalid/absent HTTP code received, PING response NOT received.

• If a service is configured with “PING ONLY”, Monitorr will NOT use Curl to check status and revert to the fallback fsockopen method automatically. Below are the Monitorr status responses if the given service is configured for “PING ONLY”:

ONLINE: PING response received.

OFFLINE: PING response NOT received.

Note: There are some services/web apps that DO NOT respond to CURL despite serving a valid webpage. These services will show UNRESPONSIVE due to their inability to respond to PHP Curl, however, the service will show OFFLINE when offline. In these scenarios, it is suggested to change the service "Check Type" in the Monitorr "Services Configuration" settings page to "Ping Only". It's also a good idea to investigate why the service does not respond to cURL responses. Please see the troubleshooting wiki page for more information and the process used to possibly determine the cause: https://github.com/Monitorr/Monitorr/wiki/06-Troubleshooting.