Auto Scaling with ELB integration in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of Auto Scaling in AWS?

Auto Scaling automatically adjusts the number of running instances to match the current demand, helping maintain performance and control costs.

beginner

How does Elastic Load Balancer (ELB) work with Auto Scaling?

ELB distributes incoming traffic evenly across all healthy instances in the Auto Scaling group, ensuring no single instance is overwhelmed.

intermediate

What happens when a new instance is launched by Auto Scaling in an ELB-integrated setup?

The new instance is automatically registered with the ELB, so it starts receiving traffic once it passes health checks.

intermediate

Why is health checking important in Auto Scaling with ELB?

Health checks help ELB and Auto Scaling detect unhealthy instances and replace them, maintaining application availability and reliability.

advanced

What is a best practice when configuring Auto Scaling with ELB?

Use ELB health checks combined with Auto Scaling group health checks to ensure instances are only serving traffic when fully ready.

What does Auto Scaling do when traffic increases?

A Disables the ELB

B Launches more instances to handle the load

C Sends traffic to a single instance

D Shuts down instances to save cost

Auto Scaling launches more instances to handle increased traffic and maintain performance.

How does ELB decide which instances to send traffic to?

A Only to the newest instance

B Only to instances with the lowest CPU usage

C Randomly to any instance

D Evenly across all healthy instances

ELB distributes traffic evenly across all instances that pass health checks.

What happens if an instance fails ELB health checks?

A It continues to receive traffic

B The ELB shuts down

C It is removed from the ELB and replaced by Auto Scaling

D Traffic is redirected to the failing instance

Failing instances are removed from ELB and Auto Scaling can replace them to keep the application healthy.

Which AWS service automatically registers new instances with ELB?

A Auto Scaling

B Amazon S3

C AWS Lambda

D Amazon RDS

Auto Scaling automatically registers new instances with the ELB when they launch.

What is a key benefit of integrating Auto Scaling with ELB?

A Automatic traffic distribution and scaling

B Static number of instances

C Manual traffic routing

D No health checks needed

Integration allows automatic scaling and balanced traffic distribution for better availability.

Explain how Auto Scaling and ELB work together to maintain application availability.

Think about how traffic and instance health are managed automatically.

Describe the role of health checks in Auto Scaling with ELB integration.

Consider why it is important to know if an instance is working well.