Monitoring the index segments means monitoring the health of an index. It contains information about the number of segments and the data that is stored in them.
Monitoring segments with the segment API
Getting ready
You will need an up-and-running Elasticsearch installation – similar to the one that we described in the Downloading and installing Elasticsearch recipe in Chapter 1, Getting Started.
In order to execute the commands, any HTTP client can be used, such as curl (https://curl.haxx.se/) or postman (https://www.getpostman.com/). You can use the Kibana console as it provides code completion and better character escaping for Elasticsearch.