In Elasticsearch, we can check the health of the cluster. Cluster health helps to show the health status of the cluster. It defines how many clusters are currently running in Elasticsearch. The health status is shown by three different colors, i.e., either Red, Green, or Yellow. Each color defines the different health status of a cluster.
RED color indicates that some of the primary shards or nodes are not available in the cluster.
RED - The cluster health status will be RED when some of the primary shards or nodes is not available in the cluster.
YELLOW - The cluster health status will be RED when some or all shards are not allocated to any of the cluster.
GREEN - The cluster health status will be RED when the shards are allocated to the node.
By executing simple cluster health, we can check the health of a cluster.
GET _cluster/health
