[[cluster-stats]]
== Cluster Stats

The Cluster Stats API allows to retrieve statistics from a cluster wide perspective.
The API returns basic index metrics (shard numbers, store size, memory usage) and
information about the current nodes that form the cluster (number, roles, os, jvm
versions, memory usage, cpu and installed plugins).

[source,js]
--------------------------------------------------
GET /_cluster/stats?human&pretty
--------------------------------------------------
// CONSOLE
// TEST[setup:twitter]

Will return, for example:
["source","js",subs="attributes,callouts"]
--------------------------------------------------
{
   "_nodes" : {
      "total" : 1,
      "successful" : 1,
      "failed" : 0
   },
   "cluster_uuid": "YjAvIhsCQ9CbjWZb2qJw3Q",
   "cluster_name": "elasticsearch",
   "timestamp": 1459427693515,
   "status": "green",
   "indices": {
      "count": 1,
      "shards": {
         "total": 5,
         "primaries": 5,
         "replication": 0,
         "index": {
            "shards": {
               "min": 5,
               "max": 5,
               "avg": 5
            },
            "primaries": {
               "min": 5,
               "max": 5,
               "avg": 5
            },
            "replication": {
               "min": 0,
               "max": 0,
               "avg": 0
            }
         }
      },
      "docs": {
         "count": 10,
         "deleted": 0
      },
      "store": {
         "size": "16.2kb",
         "size_in_bytes": 16684
      },
      "fielddata": {
         "memory_size": "0b",
         "memory_size_in_bytes": 0,
         "evictions": 0
      },
      "query_cache": {
         "memory_size": "0b",
         "memory_size_in_bytes": 0,
         "total_count": 0,
         "hit_count": 0,
         "miss_count": 0,
         "cache_size": 0,
         "cache_count": 0,
         "evictions": 0
      },
      "completion": {
         "size": "0b",
         "size_in_bytes": 0
      },
      "segments": {
         "count": 4,
         "memory": "8.6kb",
         "memory_in_bytes": 8898,
         "terms_memory": "6.3kb",
         "terms_memory_in_bytes": 6522,
         "stored_fields_memory": "1.2kb",
         "stored_fields_memory_in_bytes": 1248,
         "term_vectors_memory": "0b",
         "term_vectors_memory_in_bytes": 0,
         "norms_memory": "384b",
         "norms_memory_in_bytes": 384,
         "points_memory" : "0b",
         "points_memory_in_bytes" : 0,
         "doc_values_memory": "744b",
         "doc_values_memory_in_bytes": 744,
         "index_writer_memory": "0b",
         "index_writer_memory_in_bytes": 0,
         "version_map_memory": "0b",
         "version_map_memory_in_bytes": 0,
         "fixed_bit_set": "0b",
         "fixed_bit_set_memory_in_bytes": 0,
         "max_unsafe_auto_id_timestamp" : -9223372036854775808,
         "file_sizes": {}
      }
   },
   "nodes": {
      "count": {
         "total": 1,
         "data": 1,
         "coordinating_only": 0,
         "master": 1,
         "ingest": 1
      },
      "versions": [
         "{version}"
      ],
      "os": {
         "available_processors": 8,
         "allocated_processors": 8,
         "names": [
            {
               "name": "Mac OS X",
               "count": 1
            }
         ],
         "mem" : {
            "total" : "16gb",
            "total_in_bytes" : 17179869184,
            "free" : "78.1mb",
            "free_in_bytes" : 81960960,
            "used" : "15.9gb",
            "used_in_bytes" : 17097908224,
            "free_percent" : 0,
            "used_percent" : 100
         }
      },
      "process": {
         "cpu": {
            "percent": 9
         },
         "open_file_descriptors": {
            "min": 268,
            "max": 268,
            "avg": 268
         }
      },
      "jvm": {
         "max_uptime": "13.7s",
         "max_uptime_in_millis": 13737,
         "versions": [
            {
               "version": "1.8.0_74",
               "vm_name": "Java HotSpot(TM) 64-Bit Server VM",
               "vm_version": "25.74-b02",
               "vm_vendor": "Oracle Corporation",
               "count": 1
            }
         ],
         "mem": {
            "heap_used": "57.5mb",
            "heap_used_in_bytes": 60312664,
            "heap_max": "989.8mb",
            "heap_max_in_bytes": 1037959168
         },
         "threads": 90
      },
      "fs": {
         "total": "200.6gb",
         "total_in_bytes": 215429193728,
         "free": "32.6gb",
         "free_in_bytes": 35064553472,
         "available": "32.4gb",
         "available_in_bytes": 34802409472
      },
      "plugins": [
        {
          "name": "analysis-icu",
          "version": "{version}",
          "description": "The ICU Analysis plugin integrates Lucene ICU module into elasticsearch, adding ICU relates analysis components.",
          "classname": "org.elasticsearch.plugin.analysis.icu.AnalysisICUPlugin",
          "has_native_controller": false
        },
        {
          "name": "ingest-geoip",
          "version": "{version}",
          "description": "Ingest processor that uses looksup geo data based on ip adresses using the Maxmind geo database",
          "classname": "org.elasticsearch.ingest.geoip.IngestGeoIpPlugin",
          "has_native_controller": false
        },
        {
          "name": "ingest-user-agent",
          "version": "{version}",
          "description": "Ingest processor that extracts information from a user agent",
          "classname": "org.elasticsearch.ingest.useragent.IngestUserAgentPlugin",
          "has_native_controller": false
        },
        ...
      ],
      ...
   }
}
--------------------------------------------------
// TESTRESPONSE[s/"plugins": \[[^\]]*\]/"plugins": $body.$_path/]
// TESTRESPONSE[s/\.\.\./"network_types": "replace_me"/]
// TESTRESPONSE[s/: (\-)?[0-9]+/: $body.$_path/]
// TESTRESPONSE[s/: "[^"]*"/: $body.$_path/]
// These replacements do a few things:
// 1. Ignore the contents of the `plugins` object because we don't know all of
//    the plugins that will be in it. And because we figure folks don't need to
//    see an exhaustive list anyway.
// 2. The last ... contains more things that we don't think are important to
//    include in the output.
// 3. All of the numbers and strings on the right hand side of *every* field in
//    the response are ignored. So we're really only asserting things about the
//    the shape of this response, not the values in it.

This API can be restricted to a subset of the nodes using the `?nodeId`
parameter, which accepts <<cluster-nodes,node filters>>:

[source,js]
--------------------------------------------------
GET /_cluster/stats?nodeId=node1,node*,master:false
--------------------------------------------------
// CONSOLE