You can configure listening rules to distribute heavy traffic among ECC instances that are attached as backend servers to ELB instances. You can also use the session persistence feature to forward all of the requests from the same client to the same backend ECC instance to enhance access efficiency.
You can extend the service capability of your applications by adding or removing backend ECC instances to suit your business needs. ELB can be used for both web servers and application servers
You can attach multiple ECC instances to a ELB instance. When an ECC instance malfunctions, ELB automatically isolates this ECC instance and distributes inbound requests to other healthy ECC instances, ensuring that your applications continue to run properly.
To provide more stable and reliable load balancing services, ELB allows you to deploy ELB instances across multiple zones in most regions for disaster recovery. Specifically, you can deploy a ELB instance in two zones within the same region. One zone is the primary zone, while the other zone is the secondary zone. If the primary zone fails or becomes unavailable, the ELB instance will fail over to the secondary zone in about 30 seconds. When the primary zone recovers, the ELB instance will automatically switch back to the primary zone.
You can deploy ELB instances in different regions and attach ECC instances of different zones within the same region to a ELB instance. You can use DNS to resolve domain names to service addresses of ELB instances in different regions for global load balancing purposes. When a region becomes unavailable, you can temporarily stop DNS resolution within that region without affecting user acces.