Networking & Content Delivery: ELB
ELB service and its varations will be discussed in this lesson, followed by our recommendations on the use of ELB service of AWS.
ELB is a load balancer service and comes in three variants:
- Classic
- Application (ALB)
- Network (NLB)
Classic
Classic is a legacy option and remains there only because it works with very old AWS accounts, where you can still run EC2 instances outside of a VPC. For any new setup, you should choose one of the other two variants.
ALB
ALBs are proper reverse proxies that sit between the internet and your application. Every request to your application gets handled by the load balancer first. The load balancer then makes another request to your application and finally forwards the response from your application to the caller. ALBs have lots of features, and they support sophisticated routing rules, redirects, responses from Lambda functions, authentication, sticky sessions, and many other things. ...