Monitoring Elasticsearch

Elasticsearch exposes a rich set of APIs known as stats APIs to monitor Elasticsearch at cluster, node, and indices levels. Some of those APIs are _cluster/stats, _nodes/stats, and myindex/stats. These APIs provide state/monitoring information in real time and the statistics presented in these APIs is point-in-time and in .json format. As an administrator/developer, when working with Elasticsearch, one would be interested in both real-time statistics as well as historical statistics, which would help them in understanding/analyzing the behavior (health or performance) of a cluster better.

Also, reading through a set of numbers for a period of time (say, for example, to find out the JVM utilization over time) would be very difficult. Rather, a UI that pictorially represents these numbers as graphs would be very useful in visualizing and analyzing the current and past trends/behaviors (health or performance) of the Elasticsearch cluster. This is where the monitoring...