title: elasticsearch 7.X cluster with specified master node
body: <p>I have 3 elastic node , How can I cluster there three nodes with always same master node , I didn't find any good docs about new elastic 7 way of specify discovery and master node:</p>
  
  <pre><code>discovery.seed_hosts: [ ]
  
  cluster.initial_master_nodes: []
  </code></pre>
  
  <p>for example I have node <code>a, b, c</code> and I want node <code>a</code> to be master what what should be <code>discovery.seed_hosts</code> and <code>cluster.initial_master_nodes</code> for master node and child nodes</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>with using Daniel answer , and checking ports are open and node have same cluster name , other nodes didn't join cluster, is there any additional config needed?</p>
  
  <p><strong>UPDATE 2</strong></p>
  
  <p>looks like nodes found each other but for some reason can't choose master node with election:</p>
  
  <blockquote>
    <p>master not discovered or elected yet, an election requires 2 nodes
    with ids [wOZEfOs9TvqGWIHHcKXtkQ, Cs0xaF-BSBGMGB8a-swznA]</p>
  </blockquote>
  
  <p><strong>Solution</strong></p>
  
  <p>Deleting folder data of all nodes start a node and then add other nodes with first node (as master) as seed host.</p>