title: Creating separate elasticsearch nodes of master+data and client+data
body: <p>We currently have a beefy 12 node cluster where all the nodes are master eligible, clients, and data.
  Recently we hit a split brain issue where the master was unresponsive long enough that another node elected itself. This despite all the nodes being up and minimum_master_nodes set to 7 (the new master could see 10 other eligible nodes).
  We'd like to reduce the risk of this by setting just 3 of the nodes to be master eligible and the other 9 to be clients, while all 12 remain data nodes.
  I had assumed we could just set:</p>
  
  <pre><code>node.master: true
  node.client: false
  node.data: true
  </code></pre>
  
  <p>on 3 of the nodes and:</p>
  
  <pre><code>node.master: false
  node.client: true
  node.data: true
  </code></pre>
  
  <p>on the other 9.
  That resulted in: </p>
  
  <pre><code>"org.elasticsearch.ElasticsearchIllegalStateException: node is not configured to store local location" 
  </code></pre>
  
  <p>I've been searching to no avail. Is there a right way to accomplish this?</p>