title: Route53 + Elastic Load Balancer not responding, but individual instances are working
body: <p>This is a confusing situation but let me try my level best to present my problem.</p>
  
  <p>I am trying my hand at setting up an aws app architecture by following this blueprint: <a href="https://s3.amazonaws.com/awsmedia/architecturecenter/AWS_ac_ra_web_01.pdf" rel="nofollow noreferrer">https://s3.amazonaws.com/awsmedia/architecturecenter/AWS_ac_ra_web_01.pdf</a></p>
  
  <p>I don't require the web server part of it, so the components that I am trying to set up are Route53 -> Elastic Load Balancer -> (A subnet containing two ec2 instances that contain my nodejs app)</p>
  
  <p>I have created a hosted zone on Route53, and I created a set record with an alias set to the ELB. </p>
  
  <p>At first, I did not setup NGINX on my EC2 instances and in my ELB configuration I registered my EC2 instances on the port on which the application runs, i.e 9000. At this point, if I tried to access my app via the domain name, the page was unreachable, and I tried to access it via the ELB DNS, it returned with 504.</p>
  
  <p>Then I set up Nginx on my instances and registered instances on ELB with port 80, and this time ELB returned with 503, however the page is still unreachable via Route53</p>
  
  <p>I am using an application load balancer with HTTPS protocol.</p>
  
  <p>So, at this point, I can't access my app via Route53, and I am getting 503 when I access it via ELB DNS, however, if I point my browser to the public dns of either of my ec2 instances, I am getting response from my APIs.</p>
  
  <p>Can anyone help me with this?</p>