inhibiting alerts on different datacenters

[dc3o]

Have multiple datacenters - each running own Prometheus instance. During maintenance - I'd like to inhibit all the alerts in datacenter A, and only those alerts in datacenter B that are related to A being down. This would be scenario for avoiding alerts for db broken replication between datacenters.

Thinking about creating these rules in each dc:

      - alert: MaintenanceMode

        expr: maintenance_mode == 1 

        for: 1m

        labels:

          severity: warning

        annotations:

          summary: This is a maintenance alert for {{ $labels.instance }}.

      - alert: SatelliteMaintenanceMode

        expr: maintenance_mode == 2

        for: 1m

        labels:

          severity: warning

        annotations:

          summary: This is a satellite maintenance alert for {{ $labels.instance }}.

Than in alertmanager inhibition section I would try with

  - source_match:

      alertname: MaintenanceMode

    target_match_re:

      severity: 'warning|critical'

  - source_match:

      alertname: SatelliteMaintenanceMode

    target_match_re:

      alertname: 'MySQLReplicationNotRunning'

      channel_name: .*

Metrics would be set exclusively so that Maintenance Alert is triggered on only one datacenter at the time. Concern is should each rule use the same metric to trigger the inhibition or to create different metrics?