title: Does an Azure Web App care if its instances are healthy/unhealthy?
body: <p>If I deploy a web app (formerly known as an Azure WebSite) to an App Hosting Plan in Azure with a couple of instances (scale = 2) <em>will the load balancer in front of the instances care if any of the instances is unhealthy?</em></p>
  
  <p>I'm troubleshooting an issue that sometimes causes my site to return an http 503 ~50% of the time. My thinking here is that <em>one of two</em> of my instances has failed but the load balancer hasn't noticed.</p>
  
  <p>If the load balancer <em>does care</em>, what does it look for? I can't find anyway to specify a ping url, for instance.</p>
  
  <p>Note: this question has <em>nothing</em> to do with Traffic Manager.</p>