Cluster health
The most basic cluster health request returns a simple status of the health of your cluster. OpenSearch expresses cluster health in three colors: green, yellow, and red. A green status means all primary shards and their replicas are allocated to nodes. A yellow status means all primary shards are allocated to nodes, but some replicas aren’t. A red status means at least one primary shard is not allocated to any node.
This request waits 50 seconds for the cluster to reach the yellow status or better:
All cluster health parameters are optional.