Elastic Load Balancing (ELB)

Correct Answer: None - there is no specified limit

AWS does not impose any limit on the number of listeners that can be configured on an Elastic Load Balancer. However, it is a good practice to only configure the listeners that are necessary for the application to function properly, as each listener adds some overhead to the load balancer's processing.

Correct Answer: Auto Scaling and Elastic Load Balancing (ELB) are two different but complementary services that work together to ensure that an application provides a consistent user experience. Auto Scaling is a service that automatically adjusts the number of instances running in response to changes in traffic patterns, while ELB distributes traffic evenly across instances to avoid overloading any single instance.

Auto Scaling and Elastic Load Balancing are two complementary services that work together to scale applications and ensure a consistent user experience. Auto Scaling automatically adjusts the number of instances running based on changes in traffic patterns, while Elastic Load Balancing evenly distributes traffic across instances to avoid overloading any single instance. When used together, these services provide the best possible user experience by ensuring that an application is always running on the right number of instances and that traffic is distributed evenly across those instances.

Correct Answer: A health check is a periodic test that determines whether an instance is available to receive traffic from the Elastic Load Balancer. A failing health check can trigger ELB to stop sending traffic to an unhealthy target instance.

In Elastic Load Balancing, a health check is used to determine whether an instance is healthy and available to receive incoming traffic. The health check monitors the status of the instance by sending a request to the instance and checking the response. If the response is successful, the instance is marked as healthy, and traffic is sent to it. If the response is unsuccessful, the instance is marked as unhealthy, and traffic is not sent to it. The health check is a critical component of Elastic Load Balancing as it ensures that traffic is routed only to healthy instances, thereby reducing the risk of application downtime and improving user experience.