Search pool size for Elasticsearch 5

Hi,

The default size of search pool size is 1000 in Elasticsearch 5
How can I change it?

For Elasticsearch 2, I can change it in elasticsearch.yml, but I got error if I add the same configure to it.

Thank you very much!

Johnny

Here: https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-threadpool.html

If you can't make it work please describe what you did and what is the error message.