Configuring Elastic Load Balancing

The Elastic Load Balancer (ELB) works within a single AWS region. You can scale both horizontally (adding more EC2 instances) and vertically (increasing EC2 instance size) within AWS, but it's best practice to scale horizontally. It can, however, load balance across several instances in multiple availability zones. If you don't want to load balance instances across multiple availability zones, then you can also disable it. If we want to load balance the instances across multiple regions, then we have to use Route 53 (instead of an ELB). ELB continuously checks the health of the instances, and only routes traffic to healthy instances. The health check frequency and the URL parameters are configurable.

If a healthy ...

Get Amazon EC2 Cookbook now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.