OpenSearch/docs/reference/cluster/nodes-stats.asciidoc

[[cluster-nodes-stats]]
=== Nodes Stats

Returns cluster nodes statistics.


[[cluster-nodes-stats-api-request]]
==== {api-request-title}

`GET /_nodes/stats` +

`GET /_nodes/<node_id>/stats` +

`GET/_nodes/stats/<metric>` +

`GET/_nodes/<node_id>/stats/<metric>` +

`GET /_nodes/stats/<metric>/<index_metric>` +

`GET /_nodes/<node_id>/stats/<metric>/<index_metric>`


[[cluster-nodes-stats-api-desc]]
==== {api-description-title}

You can use the cluster nodes stats API to retrieve statistics for nodes in a cluster.


All the nodes selective options are explained <<cluster-nodes,here>>.

By default, all stats are returned. You can limit the returned information by 
using metrics.

[[cluster-nodes-stats-api-path-params]]
==== {api-path-parms-title}


`<metric>`::
    (Optional, string) Limits the information returned to the specific metrics. 
    A comma-separated list of the following options: 
+
--
  `adaptive_selection`::
      Statistics about <<search-adaptive-replica,adaptive replica selection>>.
      
  `breaker`::
      Statistics about the field data circuit breaker.
      
  `discovery`::
      Statistics about the discovery.
          
  `fs`::
      File system information, data path, free disk space, read/write
      stats.
          
  `http`::
      HTTP connection information.
  
  `indices`::
      Indices stats about size, document count, indexing and deletion times, 
      search times, field cache size, merges and flushes.
      
  `ingest`::
      Statistics about ingest preprocessing.
  
  `jvm`::
      JVM stats, memory pool information, garbage collection, buffer
      pools, number of loaded/unloaded classes.

  `os`::
      Operating system stats, load average, mem, swap.

  `process`::
      Process statistics, memory consumption, cpu usage, open
      file descriptors.

  `thread_pool`::
      Statistics about each thread pool, including current size, queue and 
      rejected tasks.

  `transport`::
      Transport statistics about sent and received bytes in cluster 
      communication.
--

`<index_metric>`::
    (Optional, string) Limit the information returned for `indices` metric to 
    the specific index metrics. It can be used only if `indices` (or `all`) 
    metric is specified. Supported metrics are:
+    
--
    * `completion`
    * `docs`
    * `fielddata`
    * `flush`
    * `get`
    * `indexing`
    * `merge`
    * `query_cache`
    * `recovery`
    * `refresh`
    * `request_cache`
    * `search`
    * `segments`
    * `store`
    * `translog`
    * `warmer`
--

include::{docdir}/rest-api/common-parms.asciidoc[tag=node-id]


[[cluster-nodes-stats-api-query-params]]
==== {api-query-parms-title}

`completion_fields`::
    (Optional, string) A comma-separated list of fields for `fielddata` and 
    `suggest` index metric (supports wildcards).

`fielddata_fields`::
    (Optional, string) A comma-separated list of fields for `fielddata` index 
    metric (supports wildcards).

`fields`::
    (Optional, string) A comma-separated list of fields for `fielddata` and 
    `completion` index metric (supports wildcards).

`groups`::
    (Optional, string) A comma-separated list of search groups for `search` 
    index metric.

`level`::
    (Optional, string) Returns indices stats aggregated at index, node or shard 
    level. Supported options: `indices`, `node`, `shards`.

`types`::
    (Optional, string) A comma-separated list of document types for the 
    `indexing` index metric.

include::{docdir}/rest-api/common-parms.asciidoc[tag=timeoutparms]

`include_segment_file_sizes`::
    (Optional, boolean) If `true`, the call reports the aggregated disk usage of 
    each one  of the Lucene index files (only applies if segment stats are 
    requested). Defaults to `false`.


[[cluster-nodes-stats-api-response-body]]
==== {api-response-body-title}

The `fs` flag can be set to retrieve information that concern the file system:

`fs.timestamp`::
    Last time the file stores statistics have been refreshed.

`fs.total.total_in_bytes`::
    Total size (in bytes) of all file stores.

`fs.total.free_in_bytes`::
    Total number of unallocated bytes in all file stores.

`fs.total.available_in_bytes`::
    Total number of bytes available to this Java virtual machine on all file 
    stores. Depending on OS or process level restrictions, this might appear 
    less than `fs.total.free_in_bytes`. This is the actual amount of free disk 
    space the {es} node can utilise.

`fs.data`::
    List of all file stores.

`fs.data.path`::
    Path to the file store.

`fs.data.mount`::
    Mount point of the file store (ex: /dev/sda2).

`fs.data.type`::
    Type of the file store (ex: ext4).

`fs.data.total_in_bytes`::
    Total size (in bytes) of the file store.

`fs.data.free_in_bytes`::
    Total number of unallocated bytes in the file store.

`fs.data.available_in_bytes`::
    Total number of bytes available to this Java virtual machine on this file 
    store.

`fs.io_stats.devices` (Linux only)::
    Array of disk metrics for each device that is backing an {es} data path. 
    These disk metrics are probed periodically and averages between the last 
    probe and the current probe are computed.

`fs.io_stats.devices.device_name` (Linux only)::
    The Linux device name.

`fs.io_stats.devices.operations` (Linux only)::
    The total number of read and write operations for the device completed since 
    starting {es}.

`fs.io_stats.devices.read_operations` (Linux only)::
    The total number of read operations for the device completed since starting 
    {es}.

`fs.io_stats.devices.write_operations` (Linux only)::
    The total number of write operations for the device completed since starting 
    {es}.

`fs.io_stats.devices.read_kilobytes` (Linux only)::
    The total number of kilobytes read for the device since starting {es}.

`fs.io_stats.devices.write_kilobytes` (Linux only)::
    The total number of kilobytes written for the device since starting {es}.

`fs.io_stats.operations` (Linux only)::
    The total number of read and write operations across all devices used by 
    {es} completed since starting {es}.

`fs.io_stats.read_operations` (Linux only)::
    The total number of read operations for across all devices used by {es} 
    completed since starting {es}.

`fs.io_stats.write_operations` (Linux only)::
    The total number of write operations across all devices used by {es} 
    completed since starting {es}.

`fs.io_stats.read_kilobytes` (Linux only)::
    The total number of kilobytes read across all devices used by {es} since 
    starting {es}.

`fs.io_stats.write_kilobytes` (Linux only)::
    The total number of kilobytes written across all devices used by {es} since 
    starting {es}.

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

`os.timestamp`::
    Last time the operating system statistics have been refreshed.

`os.cpu.percent`::
    Recent CPU usage for the whole system, or -1 if not supported.

`os.cpu.load_average.1m`::
    One-minute load average on the system (field is not present if one-minute 
    load average is not available).
    
`os.cpu.load_average.5m`::
    Five-minute load average on the system (field is not present if five-minute 
    load average is not available).

`os.cpu.load_average.15m`::
    Fifteen-minute load average on the system (field is not present if 
    fifteen-minute load average is not available).

`os.mem.total_in_bytes`::
    Total amount of physical memory in bytes.

`os.mem.free_in_bytes`::
    Amount of free physical memory in bytes.

`os.mem.free_percent`::
    Percentage of free memory.

`os.mem.used_in_bytes`::
    Amount of used physical memory in bytes.

`os.mem.used_percent`::
    Percentage of used memory.

`os.swap.total_in_bytes`::
    Total amount of swap space in bytes.

`os.swap.free_in_bytes`::
    Amount of free swap space in bytes.

`os.swap.used_in_bytes`::
    Amount of used swap space in bytes.

`os.cgroup.cpuacct.control_group` (Linux only)::
    The `cpuacct` control group to which the {es} process belongs.

`os.cgroup.cpuacct.usage_nanos` (Linux only)::
    The total CPU time (in nanoseconds) consumed by all tasks in the same cgroup 
    as the {es} process.

`os.cgroup.cpu.control_group` (Linux only)::
    The `cpu` control group to which the {es} process belongs.

`os.cgroup.cpu.cfs_period_micros` (Linux only)::
    The period of time (in microseconds) for how regularly all tasks in the same 
    cgroup as the {es} process should have their access to CPU resources 
    reallocated.

`os.cgroup.cpu.cfs_quota_micros` (Linux only)::
    The total amount of time (in microseconds) for which all tasks in
    the same cgroup as the {es} process can run during one period 
    `os.cgroup.cpu.cfs_period_micros`.

`os.cgroup.cpu.stat.number_of_elapsed_periods` (Linux only)::
    The number of reporting periods (as specified by
    `os.cgroup.cpu.cfs_period_micros`) that have elapsed.

`os.cgroup.cpu.stat.number_of_times_throttled` (Linux only)::
    The number of times all tasks in the same cgroup as the {es} process have 
    been throttled.

`os.cgroup.cpu.stat.time_throttled_nanos` (Linux only)::
    The total amount of time (in nanoseconds) for which all tasks in the same 
    cgroup as the {es} process have been throttled.

`os.cgroup.memory.control_group` (Linux only)::
    The `memory` control group to which the {es} process belongs.

`os.cgroup.memory.limit_in_bytes` (Linux only)::
    The maximum amount of user memory (including file cache) allowed for all 
    tasks in the same cgroup as the {es} process. This value can be too big to 
    store in a `long`, so is returned as a string so that the value returned can 
    exactly match what the underlying operating system interface returns. Any 
    value that is too large to parse into a `long` almost certainly means no 
    limit has been set for the cgroup.

`os.cgroup.memory.usage_in_bytes` (Linux only)::
    The total current memory usage by processes in the cgroup (in bytes) by all 
    tasks in the same cgroup as the {es} process. This value is stored as a 
    string for consistency with `os.cgroup.memory.limit_in_bytes`.

NOTE: For the cgroup stats to be visible, cgroups must be compiled into the 
kernel, the `cpu` and `cpuacct` cgroup subsystems must be configured and stats 
must be readable from `/sys/fs/cgroup/cpu` and `/sys/fs/cgroup/cpuacct`.

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

`process.timestamp`::
    Last time the process statistics have been refreshed.

`process.open_file_descriptors`::
    Number of opened file descriptors associated with the current process, or -1 
    if not supported.

`process.max_file_descriptors`::
    Maximum number of file descriptors allowed on the system, or -1 if not 
    supported.

`process.cpu.percent`::
    CPU usage in percent, or -1 if not known at the time the stats are computed

`process.cpu.total_in_millis`::
    CPU time (in milliseconds) used by the process on which the Java virtual 
    machine is running, or -1 if not supported.

`process.mem.total_virtual_in_bytes`::
    Size in bytes of virtual memory that is guaranteed to be available to the 
    running process.

The `ingest` flag can be set to retrieve statistics that concern ingest:

`ingest.total.count`::
    The total number of document ingested during the lifetime of this node

`ingest.total.time_in_millis`::
    The total time spent on ingest preprocessing documents during the lifetime 
    of this node.

`ingest.total.current`::
    The total number of documents currently being ingested.

`ingest.total.failed`::
    The total number ingest preprocessing operations failed during the lifetime 
    of this node.

On top of these overall ingest statistics, these statistics are also provided on 
a per pipeline basis.

The `adaptive_selection` flag can be set to retrieve statistics that concern
<<search-adaptive-replica,adaptive replica selection>>. These statistics are
keyed by node. For each node:

`adaptive_selection.outgoing_searches`::
    The number of outstanding search requests from the node these stats are for 
    to the keyed node.

`avg_queue_size`::
    The exponentially weighted moving average queue size of search requests on 
    the keyed node.

`avg_service_time_ns`::
    The exponentially weighted moving average service time of search requests on
    the keyed node.

`avg_response_time_ns`::
    The exponentially weighted moving average response time of search requests 
    on the keyed node.

`rank`::
    The rank of this node; used for shard selection when routing search 
    requests.


[[cluster-nodes-stats-api-example]]
==== {api-examples-title}

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

# return just os and process
GET /_nodes/stats/os,process

# return just process for node with IP address 10.0.0.1
GET /_nodes/10.0.0.1/stats/process
--------------------------------------------------
// CONSOLE

All stats can be explicitly requested via `/_nodes/stats/_all` or 
`/_nodes/stats?metric=_all`.

You can get information about indices stats on `node`, `indices`, or `shards` 
level.

[source,js]
--------------------------------------------------
# Fielddata summarized by node
GET /_nodes/stats/indices/fielddata?fields=field1,field2

# Fielddata summarized by node and index
GET /_nodes/stats/indices/fielddata?level=indices&fields=field1,field2

# Fielddata summarized by node, index, and shard
GET /_nodes/stats/indices/fielddata?level=shards&fields=field1,field2

# You can use wildcards for field names
GET /_nodes/stats/indices/fielddata?fields=field*
--------------------------------------------------
// CONSOLE

You can get statistics about search groups for searches executed
on this node.

[source,js]
--------------------------------------------------
# All groups with all stats
GET /_nodes/stats?groups=_all

# Some groups from just the indices stats
GET /_nodes/stats/indices?groups=foo,bar
--------------------------------------------------
// CONSOLE