# Elasticsearch 6.3.2 master node high CPU & load average
**URL:** https://discuss.elastic.co/t/elasticsearch-6-3-2-master-node-high-cpu-load-average/147627
**Category:** Elasticsearch
**Created:** [September 6, 2018, 7:59pm UTC](https://discuss.elastic.co/t/elasticsearch-6-3-2-master-node-high-cpu-load-average/147627 "2018-09-06T19:59:43Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Malc0lm](https://discuss.elastic.co/u/Malc0lm)
#### Post date: [September 6, 2018, 7:59pm UTC](https://discuss.elastic.co/t/elasticsearch-6-3-2-master-node-high-cpu-load-average/147627/1 "2018-09-06T19:59:43Z")
Hello,
I've upgraded from Elasticsearch version 2 to 6.3.2 on Debian Jessie from the official Elasticsearch repo.
After the upgrade I've started fresh and re-imported the data I needed.
I noticed that the cluster is sometime very slow with the master node busy in the 60-80% CPU and high load average. Index routing is super slow too after host leave or join the cluster.
The cluster has 7 hosts 3 master+data & 4 data only.
Each 2 CPU and 4GB RAM, all SSD.
It was working quite smoothly before the upgrade.
I am not sure where to start, would you have some advises please?
Thank you
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [October 4, 2018, 8:00pm UTC](https://discuss.elastic.co/t/elasticsearch-6-3-2-master-node-high-cpu-load-average/147627/2 "2018-10-04T20:00:38Z")
This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.