AWS Communism: How we cut our Load Balancing cost by more than 96%

Nothing is free. Resource sharing comes with the noisy & problematic neighbour issue. An ALB consumes 16.43 USD per month. You need to decide if it's worth the risk, blast radius would be larger in case of incidents. I've seen ALBs timing out because the ALB itself did not scale fast enough, so in a shared environment with 100 different applications, this might be amplified.

Claim 96% savings, but nothing to show for it.<p>No numbers, no examples, no use cases.<p>Very basic article to promote their service&#x2F;solution.

I&#x27;m not normally a fan of sharing ALBs between services as a lot of the metrics [1] are only recorded for the load balancer as a whole, not each individual target group (an application attached to the load balancer).<p>I can see the advantages of cost savings, but it&#x27;s definitely a tradeoff.<p>[1]: <a href="https:&#x2F;&#x2F;docs.aws.amazon.com&#x2F;elasticloadbalancing&#x2F;latest&#x2F;application&#x2F;load-balancer-cloudwatch-metrics.html" rel="nofollow">https:&#x2F;&#x2F;docs.aws.amazon.com&#x2F;elasticloadbalancing&#x2F;latest&#x2F;appl...</a>

There&#x27;s a good post to be written about this but I don&#x27;t think this is it: it makes a big claim for costs but has almost no technical information and the conclusion is basically treating it as a lead generator for their sales team.<p>The thing which would be more interesting would be talking about the cost savings (~$16&#x2F;month) relative to things like risks: mostly noisy-neighbor and the administrative concerns of coordinating changes to settings or the security considerations of someone being able to compromise multiple sites rather than just their own. There&#x27;s no wrong answer there but it&#x27;s an engineering decision which will lead to different results depending on your environment, budget, and projects.<p>Speaking of engineering, it sounds like they&#x27;re using some Go code to avoid hitting the limit on certificates and target groups. That&#x27;s certainly effective but I do wonder how many organizations have enough applications&#x2F;certificates which are appropriate for shared infrastructure and hit that limit. If your sharing is within that range, the potential cost savings are going to be lower as well.

Additional cost of not sharing ALBs is a small price to pay to avoid CloudFormation, as in this solution.

An AWS Application Load Balancer (ALB) can host up to 100 applications with 25 different TLS certificates. However, if you wanted to share this ALB, you&#x27;d need to watch how many apps you assign to it. If you tried to use it across Terraform projects, you&#x27;d need to expose its ID. At best, it&#x27;s additional work. More often, this is too much work. Thus, it&#x27;s more economical for most cloud engineers to create dedicated resources and let the client pay the bill.<p>Our way is AWS-native and allows for maximum efficient sharing – without complicating it for the user. When you can share a single ALB between 25 to 100 apps, the large cost saving comes in.

One of the main reasons I started sharing an ALB is because I had Terraform build a whole web stack&#x27;s infrastructure for every Pull Request, test the app against that stack, then destroy it all on PR close... and that was hitting the limit of # ALBs per account. Sharing an ALB allowed us to scale that CI process without hitting the limit [as quickly].