title: Elasticsearch clustering on multiple machines - master election
body: <p>I am trying to implement elasticsearch cluster. I have 2 machines with 2 nodes each. I have following configuration in <code>yml</code> file. I have given unique node name on each node, all of them are master and data nodes.</p>
  
  <pre><code>cluster.name: elasticsearch
  node.master: true
  node.data: true
  discovery.zen.ping.multicast.enabled: false
  discovery.zen.ping.unicast.hosts: ["machine1", "machine2"]
  discovery.zen.minimum_master_nodes: 3
  </code></pre>
  
  <p>the four nodes are working correctly in the cluster. I would like to bring one of the nodes down, and have other 3 run in the cluster. When I try to bring one of first three, cluster goes down, I get this error</p>
  
  <pre><code>{
     "error": "ClusterBlockException[blocked by: [SERVICE_UNAVAILABLE/1/state not recovered / initialized];]",
     "status": 503
  }
  </code></pre>
  
  <p>If I bring down the last node that joined cluster, the cluster works fine. my understanding is, if I have 4 masters and one of the master (any) goes down, other three masters should run in the cluster. is there any issue with my configuration?</p>