Hi, A customer hand me two clusters, these are in two servers, on each server there are 3 nodes on dockers, what will the best strategy to join these two clusters?
Also I was thinking that would be better to get rid of docker, it is posible to mantain the data and use the only one instance of elastic on the server? I imagine that i have to move all shards to one docker node, but It will be any inconvinience?
I feel like cross cluster search and cross cluster replication could help you with moving the data and phasing out one cluster.
There is no way to join two clusters in Elasticsearch, and a node that has been a part of one cluster can not be made to join another while retaining data and cluster state. It has to join the new cluter as a new, completely empty node.
You will therefore need to take a snaphot of the data in cluster B and then restore this to cluster A. You can then clear the nodes in cluster B and configure them to join cluster A as new, fresh nodes.