I want to switch from single node elasticsearch to three node cluster without the data loss. For that, I have modified the configuration files correctly.
Let node1 be the one with data and node2, node3 are new nodes, if I restart the node1 first, then node2 and then node3, the data isn't lost and the cluster is formed successfully.
But if I restart node2 first then node3 and then node1, then two different clusters are formed, one containing node2 and node3, another node1 acting as single node cluster with only master node.
i want answers for these:
- is it mandatory to restart the node with data first?
- without losing data can I add node1 to the cluster with nodes node2 and node3?
- is it always mandatory for new node to be empty i.e. data should not be there?