By: By: Mike Meluso, JHC Technology Senior Cloud Engineer
AWS recently announced the Network Load Balancer (NLB), and with it laid the roadmap for the future of the Elastic Load Balancer. Unlike the Application Load Balancer (ALB), NLB operates on network layer 4 and focuses on high-throughput, low-latency connections scaling to millions per second. Like ALB, it is built with containers in mind and supports dynamic host mapping, an advantage over the Classic Load Balancer (CLB) where the host port can’t be allocated dynamically when associating a new instance with the load balancer. NLB trades the path-based and host-based routing capabilities for a flow hash routing algorithm for super-fast request handling. In exchange for supporting HTTP/2 natively and allowing peered VPC or VPN IP addresses as targets, NLB allows you to connect your application to your load balancer using a static IP address, preserves the IP address of the source, and allows for long-term connections making it ideal for IoT and messaging applications. The Classic Load Balancer doesn’t support any of these features.
With the addition of the NLB to the ELB family, all functionality of the Classic Load Balancer has been replaced and enhanced upon. Additionally, the pricing model for NLB matches the Load Balancer Compute Unit (LCU)-based approach introduced with the Application Load Balancer, making both current-generation options more economical than their predecessor. If you are still using Classic Load Balancers, I strongly encourage you to consider switching to the new offering to take advantage of more cost-effective options that perform better and are fully-featured. Since the NLB was introduced, AWS seems to be positioning the CLB as a soon-to-be-deprecated option, greying out the option in the console and associating it with EC2-Classic, the pre-VPC iteration of the Elastic Compute Cloud. It won’t be long before the CLB joins EBS Magnetic, S3 Reduced Redundancy, and other previous generation service offerings in the AWS archive. The Classic Load Balancer played an essential role in helping customers take advantage of the scalable nature of the cloud, but at the speed of cloud innovation it is important to move forward when AWS presents new opportunities to Simplify Your Cloud.