[[cluster-nodes-info]]
== Nodes Info

The cluster nodes info API allows to retrieve one or more (or all) of
the cluster nodes information.

[source,js]
--------------------------------------------------
GET /_nodes
GET /_nodes/nodeId1,nodeId2
--------------------------------------------------
// CONSOLE

The first command retrieves information of all the nodes in the cluster.
The second command selectively retrieves nodes information of only
`nodeId1` and `nodeId2`. All the nodes selective options are explained
<<cluster-nodes,here>>.

By default, it just returns all attributes and core settings for a node:

[float]
[[core-info]]

`build_hash`::
	Short hash of the last git commit in this release.

`host`::
	The node's host name.

`ip`::
	The node's IP address.

`name`::
	The node's name.

`total_indexing_buffer`::
	Total heap allowed to be used to hold recently indexed
	documents before they must be written to disk.  This size is
	a shared pool across all shards on this node, and is
        controlled by <<indexing-buffer,Indexing Buffer settings>>.

`total_indexing_buffer_in_bytes`::
	Same as `total_indexing_buffer`, but expressed in bytes.

`transport_address`::
	Host and port where transport HTTP connections are accepted.

`version`::
	Elasticsearch version running on this node.

It also allows to get only information on `settings`, `os`, `process`, `jvm`,
`thread_pool`, `transport`, `http`, `plugins`, `ingest` and `indices`:

[source,js]
--------------------------------------------------
# return just process
GET /_nodes/process

# same as above
GET /_nodes/_all/process

# return just jvm and process of only nodeId1 and nodeId2
GET /_nodes/nodeId1,nodeId2/jvm,process

# same as above
GET /_nodes/nodeId1,nodeId2/info/jvm,process

# return all the information of only nodeId1 and nodeId2
GET /_nodes/nodeId1,nodeId2/_all
--------------------------------------------------
// CONSOLE

The `_all` flag can be set to return all the information - or you can simply omit it.

[float]
[[os-info]]
==== Operating System information

The `os` flag can be set to retrieve information that concern
the operating system:

`os.refresh_interval_in_millis`::
	Refresh interval for the OS statistics

`os.name`::
	Name of the operating system (ex: Linux, Windows, Mac OS X)

`os.arch`::
	Name of the JVM architecture (ex: amd64, x86)

`os.version`::
	Version of the operating system

`os.available_processors`::
	Number of processors available to the Java virtual machine

`os.allocated_processors`::
    The number of processors actually used to calculate thread pool size. This number can be set
    with the `processors` setting of a node and defaults to the number of processors reported by the OS.
    In both cases this number will never be larger than 32.

[float]
[[process-info]]
==== Process information

The `process` flag can be set to retrieve information that concern
the current running process:

`process.refresh_interval_in_millis`::
	Refresh interval for the process statistics

`process.id`::
	Process identifier (PID)

`process.mlockall`::
	Indicates if the process address space has been successfully locked in memory

[float]
[[plugins-info]]
==== Plugins information

`plugins` - if set, the result will contain details about the installed plugins and modules per node:

[source,js]
--------------------------------------------------
GET /_nodes/plugins
--------------------------------------------------
// CONSOLE
// TEST[setup:node]

The result will look similar to:

[source,js]
--------------------------------------------------
{
  "_nodes": ...
  "cluster_name": "elasticsearch",
  "nodes": {
    "USpTGYaBSIKbgSUJR2Z9lg": {
      "name": "node-0",
      "transport_address": "192.168.17:9300",
      "host": "node-0.elastic.co",
      "ip": "192.168.17",
      "version": "{version}",
      "build_flavor": "{build_flavor}",
      "build_type": "zip",
      "build_hash": "587409e",
      "roles": [
        "master",
        "data",
        "ingest"
      ],
      "attributes": {},
      "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
        }
      ],
      "modules": [
        {
          "name": "lang-painless",
          "version": "{version}",
          "description": "An easy, safe and fast scripting language for Elasticsearch",
          "classname": "org.elasticsearch.painless.PainlessPlugin",
          "has_native_controller": false
        }
      ]
    }
  }
}
--------------------------------------------------
// TESTRESPONSE[s/"_nodes": \.\.\./"_nodes": $body.$_path,/]
// TESTRESPONSE[s/"elasticsearch"/$body.cluster_name/]
// TESTRESPONSE[s/"USpTGYaBSIKbgSUJR2Z9lg"/\$node_name/]
// TESTRESPONSE[s/"name": "node-0"/"name": $body.$_path/]
// TESTRESPONSE[s/"transport_address": "192.168.17:9300"/"transport_address": $body.$_path/]
// TESTRESPONSE[s/"host": "node-0.elastic.co"/"host": $body.$_path/]
// TESTRESPONSE[s/"ip": "192.168.17"/"ip": $body.$_path/]
// TESTRESPONSE[s/"build_hash": "587409e"/"build_hash": $body.$_path/]
// TESTRESPONSE[s/"roles": \[[^\]]*\]/"roles": $body.$_path/]
// TESTRESPONSE[s/"attributes": \{[^\}]*\}/"attributes": $body.$_path/]
// TESTRESPONSE[s/"plugins": \[[^\]]*\]/"plugins": $body.$_path/]
// TESTRESPONSE[s/"modules": \[[^\]]*\]/"modules": $body.$_path/]

The following information are available for each plugin and module:

* `name`: plugin name
* `version`: version of Elasticsearch the plugin was built for
* `description`: short description of the plugin's purpose
* `classname`: fully-qualified class name of the plugin's entry point
* `has_native_controller`: whether or not the plugin has a native controller process


[float]
[[ingest-info]]
==== Ingest information

`ingest` - if set, the result will contain details about the available
processors per node:

[source,js]
--------------------------------------------------
GET /_nodes/ingest
--------------------------------------------------
// CONSOLE
// TEST[setup:node]

The result will look similar to:

[source,js]
--------------------------------------------------
{
  "_nodes": ...
  "cluster_name": "elasticsearch",
  "nodes": {
    "USpTGYaBSIKbgSUJR2Z9lg": {
      "name": "node-0",
      "transport_address": "192.168.17:9300",
      "host": "node-0.elastic.co",
      "ip": "192.168.17",
      "version": "{version}",
      "build_flavor": "{build_flavor}",
      "build_type": "zip",
      "build_hash": "587409e",
      "roles": [],
      "attributes": {},
      "ingest": {
        "processors": [
          {
            "type": "date"
          },
          {
            "type": "uppercase"
          },
          {
            "type": "set"
          },
          {
            "type": "lowercase"
          },
          {
            "type": "gsub"
          },
          {
            "type": "convert"
          },
          {
            "type": "remove"
          },
          {
            "type": "fail"
          },
          {
            "type": "foreach"
          },
          {
            "type": "split"
          },
          {
            "type": "trim"
          },
          {
            "type": "rename"
          },
          {
            "type": "join"
          },
          {
            "type": "append"
          }
        ]
      }
    }
  }
}
--------------------------------------------------
// TESTRESPONSE[s/"_nodes": \.\.\./"_nodes": $body.$_path,/]
// TESTRESPONSE[s/"elasticsearch"/$body.cluster_name/]
// TESTRESPONSE[s/"USpTGYaBSIKbgSUJR2Z9lg"/\$node_name/]
// TESTRESPONSE[s/"name": "node-0"/"name": $body.$_path/]
// TESTRESPONSE[s/"transport_address": "192.168.17:9300"/"transport_address": $body.$_path/]
// TESTRESPONSE[s/"host": "node-0.elastic.co"/"host": $body.$_path/]
// TESTRESPONSE[s/"ip": "192.168.17"/"ip": $body.$_path/]
// TESTRESPONSE[s/"build_hash": "587409e"/"build_hash": $body.$_path/]
// TESTRESPONSE[s/"roles": \[[^\]]*\]/"roles": $body.$_path/]
// TESTRESPONSE[s/"attributes": \{[^\}]*\}/"attributes": $body.$_path/]
// TESTRESPONSE[s/"processors": \[[^\]]*\]/"processors": $body.$_path/]

The following information are available for each ingest processor:

* `type`: the processor type
