title: Elasticsearch Heap Size
body: <p>I have an ES cluster with 5 nodes. 1 acting as client node, 1 acting as master node and 3 as data nodes. 
  I was using the default 1GB heap for each of these nodes. 
  However, after getting Out Of Memory Exception, I increased the Heap to 16GB (I have machines upto 64GB RAM).
  After this change in configuration, I have seen an increase in the documents (Number of documents and Total index size).
  The inflow of data in both these scenarios has been constant.</p>
  
  <p>Is there a possibility, that due to low memory, ES was not indexing all my data initially?
  Thanks in Advance. :)</p>