title: duplicate data in nodes of cluster in elastic search
body: <p>why does indexing data into one node of a cluster reflect in all nodes of that cluster in elastic search?</p>
  
  <p>ex: have 3 nodes ex1,ex2,ex3 and all these nodes share same index say <code>example</code>. once I update one of node say ex1 why will that reflect in all the three nodes?</p>