I have installed 2 instances of cache channel micro servive for Staging and Live environment. I have left with default port. How can I find, which port my second instance is using? Also how can I register it as a capability with discovery service?
You can't have two instances of the service listen on the same port. One will fail.
One option is to configure the services to run on separate ports like this: Is it possible to specify your own port number for the cache microservice
You could also consider running the instances on separate servers.