cat thread pooledit

The thread_pool command shows cluster wide thread pool statistics per node. By default the active, queue and rejected statistics are returned for all thread pools.

GET /_cat/thread_pool

Which looks like:

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

The first column is the node name

node_name
node-0

The second column is the thread pool name

name
analyze
ccr (default distro only)
fetch_shard_started
fetch_shard_store
flush
force_merge
generic
get
index
listener
management
ml_autodetect (default distro only)
ml_datafeed (default distro only)
ml_utility (default distro only)
refresh
rollup_indexing (default distro only)`
search
security-token-key (default distro only)
snapshot
warmer
watcher (default distro only)
write

The next three columns show the active, queue, and rejected statistics for each thread pool

active queue rejected
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0
     1     0        0
     0     0        0
     0     0        0
     0     0        0
     0     0        0

The cat thread pool API accepts a thread_pool_patterns URL parameter for specifying a comma-separated list of regular expressions to match thread pool names.

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

which looks like:

id                     name    active rejected completed
0EWUhXeBQtaVGlexUeVwMg generic      0        0        70

Here the host columns and the active, rejected and completed suggest thread pool statistics are displayed.

All built-in thread pools and custom thread pools are available.

Thread Pool Fieldsedit

For each thread pool, you can load details about it by using the field names in the table below.

Field Name Alias Description

type

t

The current (*) type of thread pool (fixed or scaling)

active

a

The number of active threads in the current thread pool

size

s

The number of threads in the current thread pool

queue

q

The number of tasks in the queue for the current thread pool

queue_size

qs

The maximum number of tasks permitted in the queue for the current thread pool

rejected

r

The number of tasks rejected by the thread pool executor

largest

l

The highest number of active threads in the current thread pool

completed

c

The number of tasks completed by the thread pool executor

min

mi

The configured minimum number of active threads allowed in the current thread pool

max

ma

The configured maximum number of active threads allowed in the current thread pool

keep_alive

k

The configured keep alive time for threads

Other Fieldsedit

In addition to details about each thread pool, it is also convenient to get an understanding of where those thread pools reside. As such, you can request other details like the ip of the responding node(s).

Field Name Alias Description

node_id

id

The unique node ID

ephemeral_id

eid

The ephemeral node ID

pid

p

The process ID of the running node

host

h

The hostname for the current node

ip

i

The IP address for the current node

port

po

The bound transport port for the current node