title: MongoDB authentication on some databases but not others
body: <p>I can successfully set up authentication and use it with mongoDB. The issue i'm currently having is that I can't work out how to have authentication set for one database, but not others. For instance, if my databases are:</p>
  
  <pre><code>admin
  authenticatedDB
  openDB
  </code></pre>
  
  <p>I would like authenticatedDB to require authentication, whereas I'd like openDB to be freely accessible with no login. Is this possible within MongoDB?</p>
  
  <p>If it's not possible, is there a way to run two separate mongod sessions locally?</p>
  
  <p>Thanks in advance :)</p>