ECS microservices scaling with ALB target group limitation

Question

Hello,

As stated in the [alb docs](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-limits.html) the "Target Groups per Application Load Balancer" is set to 100 hard limit.

I have a customer who is using `ALB` with `ECS` to implement their microservices and are up to 75 `target groups` and will at some point hit the 100 `target group limit`. Just wondering what or if their is a recommend way to over come this limit ?

Best I can come up with is to have a small chain of `ALBs`. So have an `entry ALB` will route traffic based on some rules to say 3 other `ALBs` downstream that in turn point to the `target groups` that have the `ECS` services but not convince this is the best solution.

Is there are alternative solutions then please let me know

thanks
alexis

Answer

Hi Alexis! Warm greetings. You have mentioned that you are looking for an alternative solution to creating a chain of ALB’s.

With regards to the target group limit, unfortunately there is no way to increase the limit even if you were to reach out to AWS to increase the limit for you . 
With that being said you could potentially increase the size capacity of your target groups instances so they can take up more requets.   You could also try switching from ECS to ESK. The idea behind it is that EKS can be part of a large federated cluster architecture. all applications managed by Amazon EKS are fully compatible with applications managed by any standard Kubernetes environment. In that sense, it can be argued that Amazon EKS is more extensible than Amazon ECS.

Further more, AWS ECS at the moment offers more in-depth AWS integration than Amazon EKS, it may be considered the go to choice for straightforward container workloads if you’re looking to work only in the AWS cloud. It is also much easier for developers to learn, and has quicker prototyping mechanisms such as AWS Copilot. However, if you’re looking to run large microservices architectures, span deployments across multiple infrastructure providers, or need additional automation or flexibility provided by Kubernetes’ diverse toolsets, Amazon EKS offers more versatility with a much richer ecosystem of tools and resources.

References:

[1] https://docs.aws.amazon.com/eks/latest/userguide/getting-started.html

[2] https://docs.aws.amazon.com/eks/latest/userguide/alb-ingress.html

[3] https://aws.amazon.com/blogs/containers/amazon-ecs-vs-amazon-eks-making-sense-of-aws-container-services/

ECS microservices scaling with ALB target group limitation

Relevant content