Increasing the size of the queue in Elasticsearch?

Question

Ive been looking at my elasticsearch logs, and I came across the error

rejected execution (queue capacity 1000) on org.elasticsearch.search.action.SearchServ

Answer 1

To change the queue size one could add it in the config file for each of the nodes as follows:

threadpool.search.queue_size: .

However this would also require a cluster restart.

Up to Elasticsearch 2.x, you can update via the cluster-setting api and this would not require a cluster restart, however this option is gone with Elasticsearch 5.x and newer.

curl -XPUT  _cluster/settings -d '{
    "persistent" : {
        "threadpool.search.queue_size" : 
    }
}'

You can query the queue size as follows:

curl /_cat/thread_pool?v&h=search.queueSize