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cat thread pool API

cat APIs are only intended for human consumption using the command line or Kibana console. They are not intended for use by applications. For application consumption, use the nodes info API.

Returns thread pool statistics for each node in a cluster. Returned information includes all built-in thread pools and custom thread pools.

Request

GET /_cat/thread_pool/<thread_pool>

GET /_cat/thread_pool

Prerequisites

If the Elasticsearch security features are enabled, you must have the monitor or manage cluster privilege to use this API.

Path parameters

<thread_pool>: (Optional, string) Comma-separated list of thread pool names used to limit the request. Accepts wildcard expressions.

Query parameters

format

(Optional, string) Short version of the HTTP accept header. Valid values include JSON, YAML, etc.

h

(Optional, string) Comma-separated list of column names to display.

If you do not specify which columns to include, the API returns the default columns in the order listed below. If you explicitly specify one or more columns, it only returns the specified columns.

Valid columns are:

node_name: (Default) Node name, such as I8hydUG.
name: (Default) Name of the thread pool, such as analyze or generic.
active, a: (Default) Number of active threads in the current thread pool.
queue,q: (Default) Number of tasks in the queue for the current thread pool.
rejected, r: (Default) Number of tasks rejected by the thread pool executor.
completed, c: Number of tasks completed by the thread pool executor.
core, cr: Configured core number of active threads allowed in the current thread pool.
ephemeral_id,eid: Ephemeral node ID.
host, h: Hostname for the current node.
ip, i: IP address for the current node.
keep_alive, k: Configured keep alive time for threads.
largest, l: Highest number of active threads in the current thread pool.
max, mx: Configured maximum number of active threads allowed in the current thread pool.
node_id, id: ID of the node, such as k0zy.
pid, p: Process ID of the running node.
pool_size, psz: Number of threads in the current thread pool.
port, po: Bound transport port for the current node.
queue_size, qs: Maximum number of tasks permitted in the queue for the current thread pool.
size, sz: Configured fixed number of active threads allowed in the current thread pool.
type, t: Type of thread pool. Returned values are fixed, fixed_auto_queue_size, direct, or scaling.

help

(Optional, Boolean) If true, the response includes help information. Defaults to false.

local

(Optional, Boolean) If true, the request retrieves information from the local node only. Defaults to false, which means information is retrieved from the master node.

master_timeout

(Optional, time units) Period to wait for a connection to the master node. If no response is received before the timeout expires, the request fails and returns an error. Defaults to 30s.

s

(Optional, string) Comma-separated list of column names or column aliases used to sort the response.

size

(Optional, size unit) Multiplier used to display quantities.

v

(Optional, Boolean) If true, the response includes column headings. Defaults to false.

Examples

Example with default columns

GET /_cat/thread_pool

The API returns the following response:

node-0 analyze             0 0 0
...
node-0 fetch_shard_started 0 0 0
node-0 fetch_shard_store   0 0 0
node-0 flush               0 0 0
...
node-0 write               0 0 0

Example with explicit columns

The following API request returns the id, name, active, rejected, and completed columns. The request limits returned information to the generic thread pool.

GET /_cat/thread_pool/generic?v=true&h=id,name,active,rejected,completed

The API returns the following response:

id                     name    active rejected completed
0EWUhXeBQtaVGlexUeVwMg generic      0        0        70

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https://www.elastic.co/guide/en/elasticsearch/reference/7.17/cat-thread-pool.html