Getting Started with Lambda and Application Load Balancers

I love Lambda for its versatility and flexibility. The list of services which can invoke it is growing all the time, making it able to take on the workloads you would traditionally require EC2, or more recently containers for. One of the most recent additions to this list is the Application Load Balancer.

When the announcement was made in November 2018, I was intrigued to find out more about the use cases of these two services working together. I’m going to admit, I struggled to see a solid real-world use case for it and found similar questions being asked as mine online. After some thinking and further research, the use cases started to become clearer. The options revolve around the ability to begin to replace components of a server-based application without the need to implement messy and complex solutions.

Before I go on, you need to understand how Application Load Balancers work vs traditional Load Balancers (ELB Classic). An ALB has two additional components:

• Target Groups: A target group is used to combine groups of servers together which perform like operations.
• Listeners: These receive connection requests for a particular port and protocol (eg. 80/HTTP or 443/HTTPS) and consist of a number of rules. Rules traditionally are path based and can route traffic to…