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Nodes info

The nodes info API represents mostly static information about your cluster’s nodes, including but not limited to:

Host system information
JVM
Processor Type
Node settings
Thread pools settings
Installed plugins

Example

To get information about all nodes in a cluster, use the following query:

GET /_nodes

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To get thread pool information about the cluster manager node only, use the following query:

GET /_nodes/master:true/thread_pool

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Path and HTTP methods

GET /_nodes
GET /_nodes/<nodeId>
GET /_nodes/<metrics>
GET /_nodes/<nodeId>/<metrics>
# or full path equivalent
GET /_nodes/<nodeId>/info/<metrics>

Path parameters

The following table lists the available path parameters. All path parameters are optional.

Parameter	Type	Description
nodeId	String	A comma-separated list of nodeIds used to filter results. Supports node filters. Defaults to `_all`.
metrics	String	A comma-separated list of metric groups that will be included in the response. For example, `jvm,thread_pool`. Defaults to all metrics.

The following table lists all available metric groups.

Metric	Description
settings	A node’s settings. This is a combination of the default settings, custom settings from the configuration file, and dynamically updated settings.
os	Static information about the host OS, including version, processor architecture, and available/allocated processors.
process	Contains the process ID.
jvm	Detailed static information about the running JVM, including arguments.
thread_pool	Configured options for all individual thread pools.
transport	Mostly static information about the transport layer.
http	Mostly static information about the HTTP layer.
plugins	Information about installed plugins and modules.
ingest	Information about ingest pipelines and available ingest processors.
aggregations	Information about available aggregations.
indices	Static index settings configured at the node level.

Query parameters

You can include the following query parameters in your request. All query parameters are optional.

Parameter	Type	Description
flat_settings	Boolean	Specifies whether to return the `settings` object of the response in flat format. Default is `false`.
timeout	Time	Sets the time limit for node response. Default value is `30s`.

Example request

The following query requests the process and transport metrics from the cluster manager node:

GET /_nodes/cluster_manager:true/process,transport

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Example response

The response contains the metric groups specified in the <metrics> request parameter (in this case, process and transport):

{
  "_nodes": {
    "total": 1,
    "successful": 1,
    "failed": 0
  },
  "cluster_name": "opensearch",
  "nodes": {
    "VC0d4RgbTM6kLDwuud2XZQ": {
      "name": "node-m1-23",
      "transport_address": "127.0.0.1:9300",
      "host": "127.0.0.1",
      "ip": "127.0.0.1",
      "version": "1.3.1",
      "build_type": "tar",
      "build_hash": "c4c0672877bf0f787ca857c7c37b775967f93d81",
      "roles": [
        "data",
        "ingest",
        "master",
        "remote_cluster_client"
      ],
      "attributes": {
        "shard_indexing_pressure_enabled": "true"
      },
      "process" : {
        "refresh_interval_in_millis": 1000,
        "id": 44584,
        "mlockall": false
      },
      "transport": {
        "bound_address": [
          "[::1]:9300",
          "127.0.0.1:9300"
        ],
        "publish_address": "127.0.0.1:9300",
        "profiles": { }
      }
    }
  }
}

Response fields

The response contains the basic node identification and build info for every node matching the <nodeId> request parameter. The following table lists the response fields.

Field	Description
name	The node’s name.
transport_address	The node’s transport address.
host	The node’s host address.
ip	The node’s host IP address.
version	The node’s OpenSearch version.
build_type	The node’s build type, like `rpm`, `docker`, `tar`, etc.
build_hash	The git commit hash of the build.
total_indexing_buffer	The maximum heap size in bytes used to hold newly indexed documents. Once this heap size is exceeded, the documents are written to disk.
roles	The list of the node’s roles.
attributes	The node’s attributes.
os	Information about the OS, including name, version, architecture, refresh interval, and the number of available and allocated processors.
process	Information about the currently running process, including PID, refresh interval, and `mlockall`, which specifies whether the process address space has been successfully locked in memory.
jvm	Information about the JVM, including PID, version, memory information, garbage collector information, and arguments.
thread_pool	Information about the thread pool.
transport	Information about the transport address, including bound address, publish address, and profiles.
http	Information about the HTTP address, including bound address, publish address, and maximum content length, in bytes.
plugins	Information about the installed plugins, including name, version, OpenSearch version, Java version, description, class name, custom folder name, a list of extended plugins, and `has_native_controller`, which specifies whether the plugin has a native controller process.
modules	Information about the modules, including name, version, OpenSearch version, Java version, description, class name, custom folder name, a list of extended plugins, and `has_native_controller`, which specifies whether the plugin has a native controller process. Modules are different from plugins because modules are loaded into OpenSearch automatically, while plugins have to be installed manually.
ingest	Information about ingest pipelines and processors.
aggregations	Information about the available aggregation types.

Required permissions

If you use the Security plugin, make sure you have the appropriate permissions: cluster:monitor/nodes/info.