WARNING: Version 1.3 of Elasticsearch has passed its EOL date.

This documentation is no longer being maintained and may be removed. If you are running this version, we strongly advise you to upgrade. For the latest information, see the current release documentation.

› ›

Thread Pool

edit

Thread Pool

edit

A node holds several thread pools in order to improve how threads are managed and memory consumption within a node. There are several thread pools, but the important ones include:

`index`	For index/delete operations, defaults to `fixed`, size `# of available processors`. queue_size `200`.
`search`	For count/search operations, defaults to `fixed`, size `3x # of available processors`. queue_size `1000`.
`suggest`	For suggest operations, defaults to `fixed`, size `# of available processors`. queue_size `1000`.
`get`	For get operations, defaults to `fixed` size `# of available processors`. queue_size `1000`.
`bulk`	For bulk operations, defaults to `fixed` size `# of available processors`. queue_size `50`.
`percolate`	For percolate operations, defaults to `fixed` size `# of available processors`. queue_size `1000`.
`snapshot`	For snapshot/restore operations, defaults to `scaling` keep-alive `5m`, size `(# of available processors)/2`.
`warmer`	For segment warm-up operations, defaults to `scaling` with a `5m` keep-alive.
`refresh`	For refresh operations, defaults to `scaling` with a `5m` keep-alive.

Changing a specific thread pool can be done by setting its type and specific type parameters, for example, changing the index thread pool to have more threads:

threadpool:
    index:
        type: fixed
        size: 30

you can update threadpool settings live using Cluster Update Settings.

Thread pool types

edit

The following are the types of thread pools that can be used and their respective parameters:

`cache`

edit

The cache thread pool is an unbounded thread pool that will spawn a thread if there are pending requests. Here is an example of how to set it:

threadpool:
    index:
        type: cached

`fixed`

edit

The fixed thread pool holds a fixed size of threads to handle the requests with a queue (optionally bounded) for pending requests that have no threads to service them.

The size parameter controls the number of threads, and defaults to the number of cores times 5.

The queue_size allows to control the size of the queue of pending requests that have no threads to execute them. By default, it is set to -1 which means its unbounded. When a request comes in and the queue is full, it will abort the request.

threadpool:
    index:
        type: fixed
        size: 30
        queue_size: 1000

Processors setting

edit

The number of processors is automatically detected, and the thread pool settings are automatically set based on it. Sometimes, the number of processors are wrongly detected, in such cases, the number of processors can be explicitly set using the processors setting.

In order to check the number of processors detected, use the nodes info API with the os flag.

« Text scoring in scripts Thrift »