How i can increase thread pool queue size in Elasticsearch 5.6

Elastic Stack Elasticsearch
7

I'm sorry for that bad advise :frowning:

I see now that the setting I mentioned was introduced after version 5.6 (I'm currently using it in a 6.2 cluster where it works fine). I don't think the maximum queue size can be changed in 5.6, at least if I correctly understand the official Thread Pool documentation:

search
For count/search/suggest operations. Thread pool type is fixed with a size of int((# of available_processors * 3) / 2) + 1 , queue_size of 1000 .

The search thread pool queue size seems to be fixed to 1000 in version 5.6, as your failed attempts to change it proves. I see there is a thread_pool.index.size in 5.6 but that is something different, so unless you can upgrade your cluster to version 6.2 or higher I don't think you can change the search thread pool size.