title: Autoincrementing number unique id in Solr
body: <p>I want to generate unique keys automatically in solr. I checked the default function <a href="http://solr.pl/en/2013/07/08/automatically-generate-document-identifiers-solr-4-x/" rel="nofollow">here</a>
  but it is generating id like 1cdee8b4-c42d-4101-8301-4dc350a4d522. In my application, I need unique autoincrement numbers like we do in MySql. What should be approach to do this ? Solrj pointers would be much helpful. </p>