Amazon Elastic Load Balancing

Elastic Load Balancing (ELB) in AWS allows you to assemble arrays of similar EC2 instances to be able to distribute incoming traffic among these instances. ELB can distribute this application or network traffic across EC2 instances or containers within the same AZs or across AZs.

In addition, to help with scalability, ELB also increases availability and reliability. A core feature of ELB is the ability to implement health checks on the managed instances. An ELB health check is used to determine the health or availability of registered EC2 instances and their readiness to receive traffic. A health check is simply a message or request sent to the server and the response that may or may not be received. If the instance responds within the 200 range, everything is fine. Any other response is considered unhealthy. If an instance does not return a healthy status, it is considered unavailable and ELB will stop sending application traffic to that instance until...