title: Elasticsearch : What is the effect disabling replication and balancing
body: <p>If I have an ES cluster and an application indexing data into ES. </p>
  
  <p><strong>EDIT</strong>: The application creates indices in a dynamic way based on some business rules. </p>
  
  <p>For example, if the application listen to tweets from Twitter API based on some hashtags it creates an index in ES for each hashtag. 
  This way, each time a new hashtag comes, a new index is created in ES. </p>
  
  <p>Sometimes, shard reallocation happen and at this stage, the cluster behaves poorly as the amount of data moved between nodes is huge.</p>
  
  <p>From ES cluster API, we can disable shard reallocation and balancing. </p>
  
  <p>What will be the effects (positive and negative) of disabling the reallocation and balancing?</p>