How to collect Elasticsearch metrics

This article discusses various tools and methods to monitor the performance of Elasticsearch clusters. It covers Elasticsearch's RESTful API + JSON, Node Stats API, Cluster Stats API, Index Stats API, Cluster Health HTTP API, Pending Tasks API, and cat API. The article also introduces dedicated monitoring tools such as ElasticHQ, Kopf, and Marvel. It concludes by suggesting the use of Datadog for comprehensive monitoring of Elasticsearch health and performance in context with metrics and events from other components of your stack.