Below are details regarding what "Unknown", "Unhealthy", and "Healthy" cluster statuses represent:
Resolution
Unknown Clusters: This is a situation where either there was no event running on the cluster or we failed to collect any information about the event.
Healthy Clusters: This means that there were active events successfully captured for the cluster. The information collected about the event should not be more than a day old from the time we viewed the cluster page.
Unhealthy Clusters: This state is reflected if the information that is collected about cluster events is more than a day old. This means that there are no active tasks running on that cluster.