title: How do you do a rolling deploy with capistrano?
body: <p>We have 2 instances behind a load balancer running the same rails app with passenger.  When we deploy, the server startup time causes requests to timeout.  As a result we have a script that updates each webserver individually by taking one off the LB, deploying with cap, testing a dynamic page load, putting it back on the LB.</p>
  
  <p>How can we get capistrano to do this for us with one command?  I have been able to set it up to deploy to all instances simultaneously but they all restart at the same time and cause the site to be unavailable for 20 seconds.  </p>
  
  <p>What am I missing here?  Seems like this should be a common pattern.</p>