Get Amazon SOA-C02 Exam Practice Questions - Real and Updated

Answer : A

The requirement is to implement a failover mechanism that minimizes downtime for an Amazon RDS for MySQL Single-AZ instance that handles read and write traffic.

From the RDS User Guide -- Multi-AZ Deployments:

Multi-AZ deployments provide high availability and durability for Database (DB) instances, making them a natural fit for production database workloads.

When you create or modify your DB instance to run as a Multi-AZ deployment, Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone (AZ).

Failover is automatic and requires no manual intervention.

Why A is correct:

Multi-AZ offers automated failover in case of instance failure, with minimal application downtime.

RDS automatically redirects traffic to the standby, which is promoted as the new primary.

Why other options are incorrect:

B . Read replica is for read-only scaling. It does not support writes and is not a failover solution.

C . Auto Scaling Group cannot be applied to RDS instances, which are managed services.

D . RDS Proxy improves connection management, but does not provide failover capability for the RDS instance itself.

Answer : A

geolocation 'Geolocation routing lets you choose the resources that serve your traffic based on the geographic location of your users, meaning the location that DNS queries originate from. For example, you might want all queries from Europe to be routed to an ELB load balancer in the Frankfurt region.'

Could be confused with geoproximity - 'Geoproximity routing lets Amazon Route 53 route traffic to your resources based on the geographic location of your users and your resources. You can also optionally choose to route more traffic or less to a given resource by specifying a value, known as a bias. A bias expands or shrinks the size of the geographic region from which traffic is routed to a resource' the use case is not needed as per question.

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/routing-policy.html

Answer : C

To resolve the issue of users being frequently prompted to log in, which typically indicates that session persistence is not configured:

Sticky Sessions: Enable sticky sessions (session affinity) on the ALB's target group. This configuration makes sure that all requests from a single user during a session are directed to the same EC2 instance, rather than being load balanced to different instances which might not share session data.

Configuration: This is done in the ALB settings under the target group attributes. Sticky sessions use a user-specific cookie generated by the ALB to route requests to the designated instance.

Session Cookie: The ALB handles the session cookie automatically, but you may adjust settings like the duration that the session cookie remains valid.

Enabling sticky sessions ensures that user sessions are maintained with the same server, reducing the instances of repeated logins and improving the user experience.

Answer : B

To manage scaling of EC2 instances in response to variable SQS message loads effectively:

Monitor SQS Queue Size: Utilize Amazon CloudWatch to monitor the number of visible messages in the SQS queue. This metric gives an indication of the workload that needs to be processed by the worker instances.

Metric Math Expression: Create a CloudWatch metric math expression that calculates the approximate number of messages visible per instance. This provides a more precise scaling metric, ensuring that each instance in the Auto Scaling group has a manageable load.

Target Tracking Scaling Policy: Implement a target tracking scaling policy based on this metric math expression. Configure the Auto Scaling group to automatically adjust its size to maintain a target value for the average number of SQS messages per instance. This approach ensures that the EC2 instances scale up during high traffic periods and scale down when the message load decreases.

This solution optimizes resource utilization and cost while maintaining performance by ensuring that the worker processes are neither overwhelmed nor idle.

Answer : A

When users report that old content is still appearing on the website after modifying files in an S3 bucket used by CloudFront, creating a CloudFront invalidation is the best solution.

CloudFront Invalidation:

Invalidation is the process of removing objects from the CloudFront cache before they expire.

This ensures that the updated content is served to the users.

Creating an Invalidation:

Open the CloudFront console.

Select the distribution and go to the 'Invalidations' tab.

Create a new invalidation and specify the paths of the updated files.

Invalidating Files in Amazon CloudFront