Amazon's Elastic Load Balancing (ELB) distributes incoming traffic requests amongst multiple server instances. Servers can be located in multiple availability zones. As a best practice for mission critical applications, configuring your Elastic Load Balancer to service more than one zone is recommended. Amazon promises to send new requests to the least loaded server. Therefore, you may notice unpredictable traffic patterns across your application tier.

If you have valid Amazon Web Services (AWS) EC2 credentials, you are automatically granted the Elastic Load Balancer service. No additional service sign-ups are required, however additional charges do apply. See Amazon for current pricing information.


Further Reading