8000 is not a Dgraph port by default. Dgraph basic cluster has one zero and one alpha process.
You can see the default port at Ports Usage - Deploy
8000 is used by Ratel which is a UI application.
Ratel connects to Dgraph Alpha and has Dgraph Server Connexion configuration panel ( click on the connection URL on the top left of the UI).
I hope that helps else could you clarify the different servers you are setting up?