trigger refuses to be created

[incognito]

I have a trigger as follows {unibank:net.tcp.service[http].last(0)}=0 but I need to monitor on a different port (3000). Changing the trigger expression to {unibank:net.tcp.service[http,,3000].last(0)}=0 results in an error message 'No such host (unibank) or monitored parameter (net.tcp.service[http,,3000])'

But changing the [http,,3000] to e.g [ftp] or [http] works. How do I change the port on the HTTP service check? Thanks!

[incognito]

solution

I managed to figure this out. You need to first create an item that corresponds to the service being checked, such as creating a net.tcp.service[rails] item to check a Rails application.

In /etc/services you also need to create a line

rails 3000/tcp

to get the overall effect of checking the rails services running on port 3000.