# How i can increase thread pool queue size in Elasticsearch 5.6

**URL:** <https://discuss.elastic.co/t/how-i-can-increase-thread-pool-queue-size-in-elasticsearch-5-6/145661>\
**Category:** Elasticsearch\
**Created:** [August 23, 2018, 6:32am UTC](https://discuss.elastic.co/t/how-i-can-increase-thread-pool-queue-size-in-elasticsearch-5-6/145661 "2018-08-23T06:32:02Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![Bernt\_Rostad](https://avatars.discourse-cdn.com/v4/letter/b/3ab097/32.png) [@Bernt\_Rostad](https://discuss.elastic.co/u/Bernt_Rostad)\
**Post date:** [August 23, 2018, 7:31am UTC](https://discuss.elastic.co/t/how-i-can-increase-thread-pool-queue-size-in-elasticsearch-5-6/145661/7 "2018-08-23T07:31:28Z")

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> [@amitshar04](#):
>
> java.lang.IllegalArgumentException: unknown setting [thread\_pool.search.max\_queue\_size]

I'm sorry for that bad advise ☹

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](https://www.elastic.co/guide/en/elasticsearch/reference/5.6/modules-threadpool.html) 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.

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