Do i need to re-index?

Elastic Stack Elasticsearch
1

Hi, currently i have
10 nodes with 5 shards, 1 replica
and i don't use dedicated master node.

if i want to use 3 dedicated master node and increase the number of my nodes so the number of shards on every node is still the same (5 shards, 2 replica). should i use 15 or 18 nodes? since from what i read, 3 dedicated master node is no longer data node. And, do i need to re-indexing?

Thank you

2

If you want to go from having 5 primary shards with 1 replica to having 5 primary shards with 2 replicas you do not need to re-index. All you need to do is change number_of_replicas setting for your indices to 2. Having dedicated master nodes is good to do if you have the resources to do it.