Opsview - Supported collector cluster configurations

There should always be an odd number of collectors within a collector cluster, e.g. 1, 3, or 5. This is to help with cluster resilience and avoid split-brain issues.

Clusters with only two collectors are unsupported.

Clusters with even numbers of collectors higher than two are supported but not recommended.

If half the collectors go down in a cluster with an even number of collectors, the remaining half stops working as the clusters used by the opsview-datastore and opsview-messagequeue components lose quorum. If either of these components lack quorum, they stop accepting updates until quorum is restored.