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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
To get thread pool information about the cluster manager node only, use the following query:
GET /_nodes/master:true/thread_pool
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
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.