Config nodes ElasticSearch Production

Hello, everyone, I have 3 servers:

  • Centos 6 15GB ram, 8 CPU, 300GB disk
    Where is the best config for 3 nodes elastic search (JVM, nodes)?

I have an index about 150GB data ~4 mils record, for saving the contact of the user. this index call to update and insert a lot. Request about find 1 number in how many contacts of other, and append new data contact to list contact of a user. And 2 index for the store info (lat, lon, name .v.v..).

I have a problem when config node 1, 2 is master and data, 3 is data (Xms and Xmx 10G). node 3 regularly stop by GC overhead. but node 1 2 still alive.