example.yaml

groups:
  - name: ircd-exporter
    rules:
      # Generate a source_server label for where each instance of the exporter
      # is running to join against. Useful when running more than one exporter
      # instance per network.
      - record: irc_source_server_mapping
        expr: |
          min(
            label_replace(irc_distance == 0, "source_server", "$1", "server", "(.*)")
          ) without (server)
      # The distance between all servers where the exporter runs.
      - record: server:irc_distance
        expr: |
         irc_source_server_mapping
           + on(instance) group_right(source_server) irc_distance != 0
      # Number of servers directly linked to each server
      # (where the exporter runs, can't do for the whole network)
      - record: server:irc_servers
        expr: |
          irc_source_server_mapping
            + on(instance) group_right(source_server) count(irc_distance == 1) by (instance)
      # If there's multiple exporters then simply looking at irc_users is
      # misleading, can be fixed by simply averaging the number seen by all
      # exporters. (Due to alignment of collections this may produce non-integer
      # number of users, if that bothers you use min or max, or pick a server to
      # take readings from and use a join on irc_source_server_mapping above.)
      - record: server:irc_users
        expr: |
          avg(irc_users) by (server)