Proxy to load balancer, bandwidth?

Question

I have an Amazon Elastic Load Balancer. I can't set my domain apex -- domain.com to the ELB because Amazon doesn't provide an IP.

If I:

• set up a new EC2 instance (whih has its own IP)
• set up a reverse proxy from EC2 to ELB (HAProxy? Apache? Nginx?)
• point my DNS to the new EC2 instance that is proxying

What consequences will I face? Does this make the ELB pointless since my single EC2 instance is a a point of failure? Will the EC2 proxy be able to handle it if each instance in the ELB gets 100s of GBs of bandwidth a day?

Answer 1

My company has run into this problem. We use a 301 redirect from ourdomain.com to www.ourdomain.com. By pointing to a subdomain, you are then allowed to use a CNAME. CNAMEs point to other domains. So, www.ourdomain.com is a CNAME to ourelb.amazonaws.com.

This unfortunately produces a SPoF. If the redirect server goes down, your site stops working. However, there are services out there that do 301 redirects to a subdomain for you. They cost money, but you don't need to use have a SPoF.

Answer 2

Yes, by putting an instance in front of your other instances and proxying data to them, you would introduce another single point of failure.

Amazon doesn't give you the IP of the load balancer directly, but they give you a DNS name that resolves to the IP. Use this as a CNAME to point your domain to. I recommend using a subdomain for just your load balanced content.