title: Compute Engine HTTP Load Balancer, Instance Not Being Checked
body: <p>I have http load balancing working without issue on GCE however I've been having issues with the health-checks recently - my instances aren't being checked.</p>
  
  <p>After updating an instance group with a new image (for example), I generally restore my instances with a reboot since I have a start-up script that runs chef.</p>
  
  <p>I can see chef runs fine on the instances and I'm able to access the instances on their ephemeral ips remotely. My other instance groups are all fine.</p>
  
  <p>The problem is that the health checks never run on these instances and they're never added back. I've set the cool down period to 480 seconds per group since chef takes up to 8 mins sometimes to run and complete.</p>
  
  <p>The only way I can get the instances back is to edit the instance group - this seems to force it through. </p>
  
  <p>Or, sometimes if I wait 15 mins, the instance finally gets checked.</p>
  
  <p>Have I missed something here? Is there a something I need to do to officially get the instances back quicker.</p>