I have a problem to connect between master-node and data-node. I installed Elasticsearch 6.3 to two computers.
Before installing Searchguard on the master-node on Elasticsearch, It is possible to connect between each elasticsearch as master-node and data-node. But, after installing Searchguard, they can’t be connected.
Data-node was trying to connect with master-node. But, Master-node returned the message as “Someone speaks http plaintext instead of ssl, will close the channel”.
I used Elasticsearch 6.3 on Linux(Ubuntu 18.04).
Please, tell me how to resolve this problem.