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

As of Elasticsearch 6 the type of the search thread pool has changed to fixed_auto_queue_size, which means setting threadpool.search.queue_size in elasticsearch.yml is not enough, you have to control the min_queue_size and max_queue_size parameters as well, like this:

thread_pool.search.queue_size: 
thread_pool.search.min_queue_size: 
thread_pool.search.max_queue_size: 

I recommend using _cluster/settings?include_defaults=true to view the current thread pool settings in your nodes before making any changes. For more information about the fixed_auto_queue_size thread pool read the docs.