# CPU,RAM spec details for Elasticsearch Master & Data nodes

**URL:** <https://discuss.elastic.co/t/cpu-ram-spec-details-for-elasticsearch-master-data-nodes/276038>\
**Category:** Elasticsearch\
**Created:** [June 15, 2021, 5:14pm UTC](https://discuss.elastic.co/t/cpu-ram-spec-details-for-elasticsearch-master-data-nodes/276038 "2021-06-15T17:14:17Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![purushothamkdr143](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/purushothamkdr143/32/90242_2.png) [@purushothamkdr143](https://discuss.elastic.co/u/purushothamkdr143)\
**Post date:** [June 15, 2021, 5:14pm UTC](https://discuss.elastic.co/t/cpu-ram-spec-details-for-elasticsearch-master-data-nodes/276038/1 "2021-06-15T17:14:17Z")

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Hi All,

I am setting up elasticsearch cluster on k8s using eck operator. From the document I understood that Heapsize should be no more than 50% of Allocated RAM so passed the details accordingly.

Details:

k8 cluster: 3 nodes(4CPU,60GB RAM) - total 16cpu 180gb ram  
master nodes: 3(each - 8GB RAM, 4GB Heapsize)  
data nodes: 3(each - 16GB RAM, 8GB Heapsize)

I am doing Loadtest on ES so I have below queries.

1. Do we need to provide RAM same for both master/data nodes in my case I have provided more RAM to data nodes alone? is this correct?
2. should I provide more cpu to datanodes or same for both master & data nodes?

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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:** [June 15, 2021, 10:02pm UTC](https://discuss.elastic.co/t/cpu-ram-spec-details-for-elasticsearch-master-data-nodes/276038/2 "2021-06-15T22:02:16Z")

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All nodes in Elasticsearch need heap+system memory and CPU. However to your point, master and coordinating only nodes usually don't need as much as they won't store data.

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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:** [July 13, 2021, 10:02pm UTC](https://discuss.elastic.co/t/cpu-ram-spec-details-for-elasticsearch-master-data-nodes/276038/3 "2021-07-13T22:02:58Z")

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