Elasticsearch exposes several APIs to monitor cluster health. In this section, we will discuss the native APIs and also X-Pack monitoring, which is available via Kibana. Kibana provides a nice UI and, more importantly, historical data to compare the metrics. You can open Kibana by going to the following URL:
http://localhost:5601/
The default username and password for Kibana are elastic and changeme. You should a screen similar to this:
You can see that monitoring is available for both Elasticsearch and Kibana. If you have Logstash installed, you can also monitor Logstash.