Separate alerts when cluster is in yellow state

[gabrielcocenza]

When a cluster is in yellow state, it's because some shards are not active. This can be reached under heavy load, however if there are shards unassigned and the cluster is yellow, that means that some replicas are not allocated and it might be necessary to add new nodes in order to host all shards.

[phvalguima]

LGTM, I don't have a strong opinion on per cluster or per instance, I think per instance makes sense as the user will receive multiple alerts but they will give you an itemized view of the servers in trouble.

[Mehdi-Bendriss]

Thanks Gabriel. I would rather rather have alerting on a cluster level to not spam with alerts instead of at the instance level.