How to create a target page at EC2 instance for Load balancer's health check

Question

I set up load balancer for my EC2 instances.

All the security groups set up between load balancer and instances look fine.

The current problem is that instances status in load balancer are OutofService.

For that I think I don't have a target page for the Health Check on my instance.

What is a target page? In my instance, inside /var/www/html folder I have index.php only directing to one html page (home page) inside another folder.

So for health check, assumed that I need to have index.html (target page) inside /var/www/html.

My questions are:

Do I need to create target page index.html inside the /var/www/html folder?
What should be inside that index.html file?

score 5 · Accepted Answer · answered Mar 12 '17 at 00:44

5

The load balancer just requires that you have a page that "returns" an HTTP 200. So, as an example, you could have a page in /var/www/html named "heartbeat.php" that looks like:

<html>
 <head>
  <title>ELB Heartbeat</title>
 </head>
 <body>
 <?php echo '<p>OK</p>'; ?> 
 </body>
</html>

What this is ultimately doing is giving the Elastic Load Balancer an HTTP 200 response and a tiny packet that indicates that everything is ok.

Later, when you've gotten more usage your "heartbeat" page may want to do more - check a connection to a database and so on. That, of course, depends on your application. But for now a simple page like this will do.

You will need to configure the Elastic Load Balancer with the URL of your heartbeat page. It will be something like http://www.yoursite.tld/heartbeat.php

answered Mar 12 '17 at 00:44

stdunbar

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Wow, nice. Now I understood. – batuman Mar 12 '17 at 06:56
Yes just a small update. heartbeat.php doesn't work and heartbeat.html does. – batuman Mar 12 '17 at 12:28
@batumanthen what did you put instead of `OK'; ?>` as it doesn't work in a HTML file – Jay P. Feb 14 '19 at 22:28
you are awesome, It works perfectly. I have used the same code you shared. – Saurabh Sinha Aug 31 '20 at 12:36

score 0 · Answer 2 · answered Aug 31 '20 at 12:40

Just to add.

When I have used another index.html. My load balancer starts pointing to index.html and I have to manually reroute to my original page using below code

*

<!DOCTYPE html> <html>    <head>
      <title>Routing to main page</title>
      <meta http-equiv = "refresh" content = "1; url = http://www.example.com/index.php" />    </head>    <body>
      <p>Redirecting to another URL</p>    </body> </html>

Thanks, heartbeat code is working perfect.

How to create a target page at EC2 instance for Load balancer's health check

2 Answers2