https://www.elastic.co/guide/en/kibana/current/production.html#load-balancing

Load Balancing Across Multiple Elasticsearch Nodesedit

If you have multiple nodes in your Elasticsearch cluster, the easiest way to distribute Kibana requests across the nodes is to run an Elasticsearch client node on the same machine as Kibana. Elasticsearch client nodes are essentially smart load balancers that are part of the cluster. They process incoming HTTP requests, redirect operations to the other nodes in the cluster as needed, and gather and return the results. For more information, see 

To use a local client node to load balance Kibana requests:

1. Install Elasticsearch on the same machine as Kibana.

2. Configure the node as a client node. In elasticsearch.yml, set both node.data andnode.master to false:

   # 3. You want this node to be neither master nor data node, but
   #    to act as a "search load balancer" (fetching data from nodes,
   #    aggregating results, etc.)
   #
   node.master: false
   node.data: false

3. Configure the client node to join your Elasticsearch cluster. In elasticsearch.yml, set thecluster.name to the name of your cluster.

   cluster.name: "my_cluster"

4. Make sure Kibana is configured to point to your local client node. In kibana.yml, theelasticsearch.url should be set to localhost:9200.

   # The Elasticsearch instance to use for all your queries.
   elasticsearch.url: "http://localhost:9200"