# What happends if I change master: true, data: true node to master-only node?
**URL:** https://discuss.elastic.co/t/what-happends-if-i-change-master-true-data-true-node-to-master-only-node/42337
**Category:** Elasticsearch
**Created:** [February 21, 2016, 4:14pm UTC](https://discuss.elastic.co/t/what-happends-if-i-change-master-true-data-true-node-to-master-only-node/42337 "2016-02-21T16:14:26Z")
**Posts on this page:** 1
**Showing post:** 5
### Author:  [@dynamicscope](https://discuss.elastic.co/u/dynamicscope)
#### Post date: [February 21, 2016, 11:38pm UTC](https://discuss.elastic.co/t/what-happends-if-i-change-master-true-data-true-node-to-master-only-node/42337/5 "2016-02-21T23:38:30Z")
It's ElasticSearch `v.2.2.0`
{AWS EC2 `m4.xlarge` : 4 vCPUs, 16 GiB Mem} x 3
node-1: master/data
node-2: data-only
node-3: data-only
ES\_HEAP\_SIZE: 10g
Data: 100,000,000 docs
Indices: 13000
Shards: 3 / index
Replica: 1
p.s. Changing master/data to master-only node didn't help any. I am still getting the following.
```
[2016-02-21 22:03:47,104][WARN][monitor.jvm] [Hulk] [gc][old][18835][175] duration [3m], collections [5]/[3m], total [3m]/[1h], memory [9.9gb]->[9.9gb]/[9.9gb], all_pools {[young] [266.2mb]->[266.2mb]/[266.2mb]}{[survivor] [33.2mb]->[33.2mb]/[33.2mb]}{[old] [9.6gb]->[9.6gb]/[9.6gb]}
[2016-02-21 22:31:27,605][WARN][transport.netty] [Hulk] exception caught on transport layer [[id: 0x180573ba, /172.31.7.130:40806 => /172.31.9.135:9300]], closing connection
java.lang.OutOfMemoryError: Java heap space
at org.apache.lucene.util.CharsRefBuilder.(CharsRefBuilder.java:35)
at org.elasticsearch.common.io.stream.StreamInput.(StreamInput.java:246)
```
Only master node blows up while data nodes are okay.
What's happening in master's memory? ðŸ˜
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_[View the full topic](https://discuss.elastic.co/t/what-happends-if-i-change-master-true-data-true-node-to-master-only-node/42337)._