Heap size percentage for master and client nodes

Elastic Stack Elasticsearch
1

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

2
  1. Yes.
  2. Depends on your mapping sizes and changes. You'd have to check.
3

I see. Thanks Mark.