# Heap size percentage for master and client nodes

**URL:** <https://discuss.elastic.co/t/heap-size-percentage-for-master-and-client-nodes/44495>\
**Category:** Elasticsearch\
**Created:** [March 15, 2016, 10:04pm UTC](https://discuss.elastic.co/t/heap-size-percentage-for-master-and-client-nodes/44495 "2016-03-15T22:04:28Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![haizaar](https://avatars.discourse-cdn.com/v4/letter/h/3d9bf3/32.png) [@haizaar](https://discuss.elastic.co/u/haizaar)\
**Post date:** [March 15, 2016, 10:04pm UTC](https://discuss.elastic.co/t/heap-size-percentage-for-master-and-client-nodes/44495/1 "2016-03-15T22:04:28Z")

</div>

I'm building ES 2.2.x cluster with

- 5 dedicated data nodes, 8 cores, 20Gb RAM each; handling 1500Gb of data (about 150 shards total).
- 2 dedicated client nodes, 4 cores, 12Gb RAM each.
- 3 dedicated master nodes, 2 cores, 2Gb RAM each.

I have two questions regarding this:

1. What is heap/RAM size ratio for master and client nodes? Since they don't use any disk cache, can I set rather high to about 80%? (My queries are mostly aggregations)
2. Would 2 cores / 2GB RAM for each master node be enough for my setup?

Thanks,  
Zaar

---

<div class="post-metadata">

**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:** [March 15, 2016, 10:46pm UTC](https://discuss.elastic.co/t/heap-size-percentage-for-master-and-client-nodes/44495/2 "2016-03-15T22:46:46Z")

</div>

1. Yes.
2. Depends on your mapping sizes and changes. You'd have to check.

---

<div class="post-metadata">

**Author:** ![haizaar](https://avatars.discourse-cdn.com/v4/letter/h/3d9bf3/32.png) [@haizaar](https://discuss.elastic.co/u/haizaar)\
**Post date:** [March 16, 2016, 10:20am UTC](https://discuss.elastic.co/t/heap-size-percentage-for-master-and-client-nodes/44495/3 "2016-03-16T10:20:53Z")

</div>

I see. Thanks Mark.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 5, 2017, 11:07pm UTC](https://discuss.elastic.co/t/heap-size-percentage-for-master-and-client-nodes/44495/4 "2017-07-05T23:07:57Z")

</div>