title: Multiple updates simultaneously on same document in solr
body: <p>I have a doubt regarding solr document update. For example, when two requests to update a document in solr comes at the same time, How does solr work?</p>
  
  <ul>
  <li>Does it take one request randomly and locks write before next request comes in?</li>
  </ul>
  
  <p>Thanks in Advance</p>