By: Mike Meluso, JHC Technology Senior Cloud Engineer
The AWS Application Load Balancer broke out on the scene in about the 3rd quarter of 2016, but many AWS customers have not yet tapped into the power of ALB. ALB builds on the versatility of the original ELB (now called a “Classic Load Balancer”) but adds many customer-driven features that make it much more powerful and developer-friendly.
With the Classic Load Balancer, developers were locked into one-application-per-load-balancer, which could be expensive for low-traffic applications which still have high-availability requirements. ALB solves that issue by providing support for containers and content-based routing. You can now run multiple containers on a single instance or a cluster and utilize a single load balancer to route traffic to them. With content-based routing, you can customize traffic to route to specific servers depending on the request. You no longer need to implement complicated redirect solutions on your web and application servers and have to factor in the ephemeral nature of your infrastructure; the ALB takes care of all of that for you!
In addition to the container and content-based routing support that can make you rethink the way you design your application, ALB comes with added bonuses like HTTP/2 and WebSocket support. ALB also supports new CloudWatch metrics to help you diagnose your applications with specific HTTP codes, per-microservice metrics, and more relevant connection metrics to help you measure traffic to your app. ALB support for IPv6 is coming soon as well.
You might ask “how much do I need to spend to get these extra features?”, and the answer might be the best part: ALB is generally less than the cost of a Classic Load Balancer! The hourly running cost of the ALB is 10% lower than the CLB and uses a new measure called Load Balancer Capacity Units (LCU’s) based on the number of connections and data transfer rate. By moving from the CLB GB-month measurement to the new LCU’s, AWS states that nearly all customers can see a net reduction in their load balancing costs. It’s not just a development decision, it’s a financial decision too!
The Classic Load Balancer took the hassle out of maintaining a load balancer as a proxy or for highly-available workloads, but the downside was that there wasn’t much customization you could do. The ALB puts that power back in the hands of DevOps engineers so they can worry less about their infrastructure and focus on the application. ALB is available in all regions including GovCloud. Try one out today, or ask a JHCer how you can get started!
Product announcement for ALB: https://aws.amazon.com/blogs/aws/new-aws-application-load-balancer/
Migrating to ALB from CLB: http://docs.aws.amazon.com/elasticloadbalancing/latest/userguide/migrate-to-application-load-balancer.html