I'm curious about how AWS CloudFront integrates with an Application Load Balancer (ALB). According to some recent updates, it sounds like the ALB can serve as an origin for CloudFront. However, I'm wondering if that actually means CloudFront is caching content from the ALB, or if it's merely acting as a front for it, forwarding requests and making the ALB more accessible globally. I generally assumed that CDNs cache content from origins rather than just routing requests, so I'm a bit confused about the relationship here.
1 Answer
CloudFront effectively acts as a proxy sitting in front of your ALB. This setup offers a few advantages:
1. The connection between CloudFront and your ALB is on AWS's internal network, which often results in faster speeds compared to a direct client-to-ALB connection. It can also speed up SSL handshakes.
2. CloudFront can cache responses based on path patterns, which can help with performance if used correctly.
3. It provides more free outgoing traffic compared to directly using the ALB.
4. CloudFront maintains connection pools to your ALB, reducing the number of direct connections your ALB needs to handle.
I personally configure security groups to only allow CloudFront access to the ALB, blocking any public access directly, which enhances security too.
Could you elaborate on how you set up your security groups for that? I thought a resource policy might be needed instead.