Monitoring your cluster's state and health
Monitoring is essential when it comes to handling your cluster and ensuring it is in a healthy state. It allows administrators and develops to detect possible problems and prevent them before they occur or to act as soon as they start showing. In the worst case, monitoring allows us to do a post mortem analysis of what happened to the application—in this case, our Elasticsearch cluster and each of the nodes.
Elasticsearch provides very detailed information that allows us to check and monitor our nodes or the cluster as a whole. This includes statistics and information about the servers, nodes, indices, and shards. Of course, we are also able to get information about the entire cluster state. Before we get into the details about the mentioned API, please remember that the API is complex and we are only describing the basics. We will try to show you where to start so you'll be able to know what to look for when you need very detailed information.
