Why auto scaling matters in AWS - Challenge Your Understanding

Challenge - 5 Problems

🧠 Conceptual

intermediate

Why does auto scaling improve application availability?

Imagine your website suddenly gets many visitors. How does auto scaling help keep the site working well?

A It adds more servers automatically to handle the extra visitors, preventing slowdowns or crashes.

B It reduces the number of servers to save money, even if visitors increase.

C It sends error messages to visitors when traffic is high.

D It stops all servers to restart them when traffic spikes.

💡 Hint

Think about what happens when more people visit a website than usual.

Auto scaling adds more servers automatically when traffic increases. This keeps the website fast and available, avoiding crashes or slowdowns.

❓ Architecture

intermediate

Which AWS service combination best supports auto scaling for a web app?

You want your web app to handle changing traffic smoothly. Which AWS services should you use together?

A Amazon S3 with CloudFront and Route 53

B Amazon EC2 instances with an Auto Scaling group and Elastic Load Balancer

C AWS Lambda with API Gateway and DynamoDB

D Amazon RDS with manual instance resizing

💡 Hint

Think about services that can add or remove servers automatically.

EC2 instances in an Auto Scaling group can increase or decrease based on traffic. The Elastic Load Balancer spreads traffic evenly across instances.

❓ service_behavior

advanced

What happens when an Auto Scaling group reaches its maximum size during a traffic spike?

Your Auto Scaling group has a max size of 5 instances. Traffic suddenly spikes beyond what 5 instances can handle. What will happen?

A The Auto Scaling group will not add more instances, possibly causing slower responses or errors.

B It will automatically increase the max size to add more instances.

C It will redirect traffic to a backup data center automatically.

D It will shut down all instances to restart them.

💡 Hint

Consider what limits the Auto Scaling group has set.

The Auto Scaling group cannot exceed its max size. If traffic exceeds capacity, performance may degrade until the max size is increased manually.

❓ security

advanced

How does auto scaling affect security group rules in AWS?

Your Auto Scaling group launches new EC2 instances automatically. How should security groups be configured to maintain security?

A Disable security groups to avoid blocking traffic during scaling.

B Manually assign security groups to each new instance after launch.

C Attach the security group to the Auto Scaling group so new instances inherit the correct rules automatically.

D Use different security groups for each instance to increase security.

💡 Hint

Think about how new instances get their network rules when created automatically.

Attaching security groups to the Auto Scaling group ensures all new instances have consistent and correct network access rules automatically.

✅ Best Practice

expert

What is the best practice to optimize cost while using auto scaling in AWS?

You want to keep your app responsive but also control costs. Which approach best balances these goals?

A Use only spot instances without a minimum number to save money, ignoring availability.

B Set the maximum number of instances very high and always run that many to avoid scaling delays.

C Disable auto scaling and manually start or stop instances when you expect traffic changes.

D Set a minimum number of instances to handle normal traffic and use scaling policies to add or remove instances based on demand.

💡 Hint

Think about how to keep enough servers running for normal use but add more only when needed.

Setting a minimum ensures baseline capacity. Scaling policies add or remove instances automatically, balancing cost and performance.