Serverless Services in AWS

Fargate, Application Load Balancer, API Gateway, Docker

AWS Nomads #7: Using Docker and Fargate instead of Lambda for serverless services.

Let’s talk about containers.

I’m not going to lie, using AWS Lambda for serverless APIs is an easy and enjoyable process. But it’s not always the right solution. The lambda is a glory of architectural purity, but it is not necessarily the most practical.

Authoring, updating, maintaining, and testing lambdas are their own special challenge, and there are occasional questions about latency when initializing a dormant lambda. But there’s also a more practical concern: money.

While prototyping or demoing to clients, at a few dozen, or hundred, or perhaps thousand requests per month, lambdas have the beautiful characteristic of not costing you any money when they are not being used. But once there is regular traffic — enough to ensure the lambda is more frequently needed than not — the cost profile reverses. The per-usage charges, small as they are, suddenly start to add up, and we can quickly go from a cup of coffee a month to some rather pricy meals.

Lambdas are not the only serverless choice, however.