The human-friendly status API – using the Cat API

The Elasticsearch Admin API is quite extensive and covers almost every part of its architecture—from low-level information about Lucene to high-level information about the cluster nodes and their health. All this information is available both using the Elasticsearch Java API as well as using the REST API; however, the data is returned in the JSON format. What's more—the returned data can sometimes be hard to analyze without further parsing. For example, try to run the following request on your Elasticsearch cluster:

curl -XGET 'localhost:9200/_stats?pretty'

On our local, single node cluster, Elasticsearch returns the following information (we cut it down drastically; the full response can be found in the stats.json file provided with the book):

{
  "_shards" : {
    "total" : 60,
    "successful" : 30,
    "failed" : 0
  },
  "_all" : {
    "primaries" : {
      .
      .
      .
    },
    "total" : {
      .
      .
      .
    }
  },
  ...