# Processors setting when running multiple elaticsearch instances on same server

**URL:** <https://discuss.elastic.co/t/processors-setting-when-running-multiple-elaticsearch-instances-on-same-server/84196>\
**Category:** Elasticsearch\
**Created:** [May 2, 2017, 2:59am UTC](https://discuss.elastic.co/t/processors-setting-when-running-multiple-elaticsearch-instances-on-same-server/84196 "2017-05-02T02:59:49Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![macymin](https://avatars.discourse-cdn.com/v4/letter/m/8e7dd6/32.png) [@macymin](https://discuss.elastic.co/u/macymin)\
**Post date:** [May 2, 2017, 2:59am UTC](https://discuss.elastic.co/t/processors-setting-when-running-multiple-elaticsearch-instances-on-same-server/84196/1 "2017-05-02T02:59:49Z")

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hi

my data node server has 256G memory and 32 cores, currently we are running 3 elasticsearch instances (processors set to 8 for each instance) in the servers. but it often hit high CPU issue.

our initial thinking is 24 cores go for elasticsearch and another 8 cores for OS... is this setting correct? what's the minimum core setting for os?

the example in below article says "e.g., if you’re running two instances of Elasticsearch on a 16-core machine, set processors to 8"

[https://www.elastic.co/guide/en/elasticsearch/reference/2.4/modules-threadpool.html](https://www.elastic.co/guide/en/elasticsearch/reference/2.4/modules-threadpool.html)

it doesn't allocate any core for OS...so what should be the correct way for my setup? (btw we are running version 2.4.1)

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**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [May 2, 2017, 6:17am UTC](https://discuss.elastic.co/t/processors-setting-when-running-multiple-elaticsearch-instances-on-same-server/84196/2 "2017-05-02T06:17:41Z")

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> [@macymin](#):
>
> our initial thinking is 24 cores go for elasticsearch and another 8 cores for OS... is this setting correct? what's the minimum core setting for os?

There is no right or wrong here, but you're probably wasting lots on the OS here.

> [@macymin](#):
>
> it doesn't allocate any core for OS

Yes, but the OS still handles how the CPU is given to the JVM. If it needs something for itself then it'll allocate time. This setting is more of an affinity one rather than a dedication one.

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**Author:** ![macymin](https://avatars.discourse-cdn.com/v4/letter/m/8e7dd6/32.png) [@macymin](https://discuss.elastic.co/u/macymin)\
**Post date:** [May 29, 2017, 4:00am UTC](https://discuss.elastic.co/t/processors-setting-when-running-multiple-elaticsearch-instances-on-same-server/84196/3 "2017-05-29T04:00:55Z")

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Thanks. I will try to allocate 10 cores for each node and test out

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [June 26, 2017, 4:01am UTC](https://discuss.elastic.co/t/processors-setting-when-running-multiple-elaticsearch-instances-on-same-server/84196/4 "2017-06-26T04:01:22Z")

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