title: Monitor memory usage of AWS EC2
body: <p>I am a bit confused in monitoring of EC2 with and without Cloudwatch agent. As far as I know, Cloudwatch agent does not get installed by default on EC2 linux but some basic system metrics like CPU usage can still be monitored and shown in Cloudwatch.</p>
  <p>My questions</p>
  <ul>
  <li>If I need to monitor memory usage which is not being monitored by default in EC2 now, should I just setup Cloudwatch agent and memory usage can be published to CloudWatch metrics?</li>
  <li>What about I don't setup Cloudwatch agent but just enable detailed monitoring? Can memory usage be monitored by just enabling detailed monitoring without cloudwatch agent?</li>
  </ul>