How to upgrade to new version smoothly? without any data lost

Elastic Stack Elasticsearch
1

I install ELK 5.4.1 with RPM package last month, if I want to upgrade 5.5, is there a guide about how to do this.

The ES is cluster with 3 nodes, can I upgrade the nodes one by one?

2

Sure is - https://www.elastic.co/guide/en/elasticsearch/reference/5.5/setup-upgrade.html

3

great ! thanx a lot ! :smile_cat: