title: ElasticSearch on Cassandra data vs moving Cassandra data to ElasticSearch for Indexing
body: <p>I'm new to ElasticSearch and am trying to figure out what is the most optimal way to index 1 Terabyte of data in Cassandra. </p>
  
  <p>Two options that I understand right now are:  </p>
  
  <ol>
  <li><p>Move data periodically to ElasticSearch using the Cassandra-River plugin and then run index on the data.<br>
  Advantage: Search queries create no impact on Cassandra load<br>
  Disadvantage: Have to sync the data periodically  </p></li>
  <li><p>Without moving the data run ElasticSearch on Cassandra to index the data (not sure how will this be done).<br>
  Advantage: Data always in sync<br>
  Disadvantage: Impacts Cassandra performance ?  </p></li>
  </ol>
  
  <p>Any thoughts would be appreciated.  </p>