Roles

A role is one part of the platform a server runs. Every server in a cluster holds some of them, and each role has a page of its own on how to put it on a server, take it off, check it and move it.

xema node roles      # what this server should run, beside what it runs

How a role is placed

Services are started and stopped for you. xema node role add <role> records that a server should run one, and xema node apply makes it so.
Infrastructure is recorded only. Moving it moves data with it, so xema node apply never starts, stops or moves it.
Some are given automatically. A cluster always has a Manager and a BFF, and a server that carries a trunk is given what such a server runs.

Services

Role	What it does
Manager `manager`	the Admin UI and the cluster's administration; one per cluster, always held
BFF `bff`	what the apps connect to; several can run, one is active
Queue `queue`	callers waiting for an agent
Bridge `bridge`	a call once it is answered
Park `park`	callers waiting for something other than an agent
Recorder `recorder`	captures calls
Tone `tone`	answers a desk phone
AsterMQ `astermq`	carries the phone system's events out
Fastlane `fastlane`	carries the cluster's actions on calls in
FastAGI `fastagi`	runs a caller flow's steps
Sipper `sipper`	captures SIP traffic
Dialer `dialer`	outbound calls
Call record `simplecdr`	writes the call record: the primary, HA and DR copies
Metrics `metrics`	the numbers and their history
Integrations `integrations`	other systems; one acts
Ava `ava`	the AI voice agent; only where named

Infrastructure

Role	What it does
Database `database`	the cluster's configuration and history
Broker `broker`	events between the services
Cache `redis`	what the services share while they run
Phone system `asterisk`	the calls, trunks and phones on a server

Every server

Host is on every server, and is not a role you add or remove.