We have created elasticsearch cluster with 4 nodes which is distributed in two subnets of aws with all the nodes with the role assigned as master, data, ingest and. It was all discovered and master node is elected. While data ingest all the nodes are used and data ingestion correctly. But when we query the elasticsearch service only 2 nodes are utilized (1 is the master and another node in the same subnet) but other 2 nodes in second subnet are not getting used even there is any heavy usage on the first 2 nodes.
When we have all the node under one subnet then all the server are getting used equally. I can't get the root cause of this issue.
Version: Elasticsearch 7.1.1