SAP-C02 Continuous Improvement for Existing Solutions Practice Test 15 — 15 Questions

Question 1

A company runs a web application on EC2 instances behind an Application Load Balancer. Users report intermittent 503 errors. The Auto Scaling group has a minimum of 2 and maximum of 10 instances. CloudWatch metrics show that CPU utilization rarely exceeds 30%. What is the MOST likely cause of the 503 errors?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The ALB connection draining is enabled with a very short timeout, causing in-flight connections to be dropped.. The 503 errors are likely due to the ALB connection draining setting. If connection draining is enabled and the drain timeout is too short, in-flight requests may be terminated, causing 503 errors. Low CPU utilization suggests the instances are not overloaded.

Answer

The EC2 instances are running out of memory.

Answer

The Auto Scaling group launch configuration uses an AMI that is not compatible with the instance type.

Answer

The ALB health check is misconfigured, causing healthy instances to be marked unhealthy.

Question 2

A company is migrating a monolithic application to microservices on Amazon ECS. The application uses a legacy database that does not support distributed transactions. The team wants to ensure data consistency across services. Which solution is BEST for achieving eventual consistency with minimal code changes?

Accepted Answer

Implement the Saga pattern using AWS Step Functions.. Implementing the Saga pattern with AWS Step Functions allows orchestrating distributed transactions across services, managing rollbacks and compensating actions. This is the best approach for eventual consistency with minimal code changes.

Answer

Use Amazon DynamoDB transactions across all services.

Answer

Modify the legacy database to support two-phase commit.

Answer

Use Amazon SQS to queue all database writes and process them sequentially.

Question 3

A company is using Amazon RDS for MySQL and wants to minimize downtime during a major version upgrade. Which approach is the MOST effective?

Accepted Answer

Create a read replica with the new version, promote it to primary, and update the application endpoint.. Creating a read replica, upgrading it, and then promoting it to primary minimizes downtime because the promotion is a quick operation.

Answer

Take a snapshot, restore as a new instance with the new version, and update the application endpoint.

Answer

Launch a new RDS instance with the new version, use DMS to migrate data, and switch the application endpoint.

Answer

Use the AWS RDS modify-db-instance command with the --allow-major-version-upgrade option. This typically causes a few minutes of downtime but is the simplest.

Question 4

A company uses AWS CloudFormation to deploy infrastructure. The operations team notices that stack updates frequently fail because of updates to resources that are not supported for updates. What is the BEST way to handle this?

Accepted Answer

Use a change set to review the proposed changes before executing the update.. The best practice is to use a change set to preview changes and identify unsupported updates before executing the update.

Answer

Use AWS Config rules to prevent updates.

Answer

Delete the stack and create a new one for each update.

Answer

Use AWS Service Catalog to enforce version control.

Question 5

A company is using Amazon S3 to store sensitive documents. The security team requires that all objects be encrypted at rest using a customer-managed key (CMK) stored in AWS KMS. Additionally, the CMK must be rotated automatically every year. How should the company configure this?

Accepted Answer

Use S3 default encryption with SSE-KMS and enable automatic key rotation on the CMK.. Enable S3 default encryption with SSE-KMS and configure automatic key rotation on the CMK. This meets both requirements.

Answer

Use S3 default encryption with SSE-KMS and create a new CMK every year.

Answer

Use S3 bucket policies to enforce encryption and use KMS manual key rotation.

Answer

Use S3 default encryption with SSE-S3 and enable KMS automatic key rotation.

Question 6

A company runs a critical application on Amazon EC2 instances in an Auto Scaling group. The application needs to maintain a fixed number of instances and should automatically replace any unhealthy instance. Which scaling policy should be used?

Accepted Answer

Manual scaling with health check replacement. A manual scaling policy set to maintain a fixed number of instances combined with health checks ensures that unhealthy instances are replaced.

Answer

Scheduled scaling policy

Answer

Simple scaling policy

Answer

Target tracking scaling policy

Question 7

A company uses Amazon DynamoDB as a data store for a mobile application. The application experiences throttling errors during peak hours. The table has a provisioned read capacity of 5000 RCUs and write capacity of 2000 WCUs. The throttling is on writes. What is the MOST cost-effective solution?

Accepted Answer

Enable auto scaling for DynamoDB write capacity.. DynamoDB Accelerator (DAX) is a read cache, not for writes. The most cost-effective solution is to use DynamoDB auto scaling for writes to handle peak loads without over-provisioning.

Answer

Enable DynamoDB Accelerator (DAX) to offload writes.

Answer

Switch to on-demand capacity mode.

Answer

Increase write capacity to 4000 WCUs.

Question 8

A company wants to monitor CPU utilization of their EC2 instances and receive an alert when utilization exceeds 80% for 10 minutes. Which AWS service should be used?

Accepted Answer

Amazon CloudWatch Alarms. CloudWatch Alarms can monitor metrics and trigger actions when a threshold is breached.

Answer

Amazon Inspector

Answer

AWS Config

Answer

AWS CloudTrail

Question 9

A company is using Amazon CloudFront to distribute content globally. They want to optimize cost and performance. Which TWO actions are recommended?

Accepted Answer

Enable Regional Edge Caches to reduce load on the origin.. Using Regional Edge Caches reduces origin load and latency. Price Class selection reduces cost by limiting edge locations.

Answer

Disable compression to reduce CPU usage on the origin.

Answer

Use a single origin server to simplify configuration.

Answer

Use multiple CloudFront distributions for the same content.

Question 10

A company is designing a serverless event-driven application using AWS Lambda. The application processes messages from an Amazon SQS queue. The team needs to ensure that messages are processed in order and exactly once. Which THREE steps should be taken?

Accepted Answer

Configure the Lambda event source mapping to use the FIFO queue.. To achieve message ordering and exactly-once processing with Lambda and SQS, you must use a FIFO queue (option B) because FIFO queues preserve the order of messages. Additionally, enable the queue's content-based deduplication or provide a deduplication ID (option E) to prevent duplicate messages from being processed. Finally, set the Lambda function's reserved concurrency to 1 (option D) to ensure that only one instance of the function processes messages at a time, maintaining the order. Option A (batch window 0) is incorrect because it would cause Lambda to wait longer, but does not help with ordering. Option C (standard queue) does not guarantee ordering or deduplication.

Answer

Enable Lambda function's batch window to 0.

Answer

Use a standard SQS queue.

Question 11

A company wants to implement a centralized logging solution for multiple AWS accounts. Which TWO services should be used together?

Accepted Answer

Amazon S3. Amazon S3 serves as a central log repository, and Amazon Athena allows querying logs directly in S3.

Answer

AWS CloudTrail

Answer

Amazon RDS

Answer

AWS Config

Question 12

A company hosts a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application uses an Amazon Aurora MySQL database. Recently, the application has become slow during peak hours. The operations team notices that the database CPU utilization is high, but the number of connections is within limits. The application is read-heavy. The team wants to improve performance with minimal changes to the application code. The database is currently a single Aurora instance. Which solution should the team implement?

Accepted Answer

Add an Aurora Replica and configure the application to use the reader endpoint for read-only queries.. Adding an Aurora Replica distributes read traffic, reducing load on the primary instance. The application must be configured to use the reader endpoint for read queries.

Answer

Use Amazon DynamoDB Accelerator (DAX) to cache database queries.

Answer

Add an Amazon ElastiCache Redis cluster in front of the database.

Answer

Increase the instance size of the Aurora primary instance.

Question 13

A company has a CI/CD pipeline that builds and deploys a containerized application to Amazon ECS Fargate. The pipeline uses AWS CodeBuild to run tests and build Docker images. Recently, the pipeline has been failing intermittently with the error 'CannotPullContainerError: Error response from daemon: manifest for <image> not found'. The image is stored in Amazon ECR. The team suspects the issue is related to image tag inconsistency. The pipeline tags images with the commit hash. Which change will prevent this error?

Accepted Answer

Ensure the pipeline builds and pushes the image with a unique tag, such as the commit hash, and uses that tag in the ECS task definition.. Ensuring that the image tag is unique and not reused prevents stale image references. Using the commit hash ensures uniqueness.

Answer

Store the Docker image in Amazon S3 instead of ECR.

Answer

Use the 'latest' tag for all images.

Answer

Retry the failed pipeline step after a delay.

Question 14

A company runs a web application on EC2 instances behind an Application Load Balancer. Users report intermittent 503 errors. The Auto Scaling group has a minimum of 2 and maximum of 10 instances. CloudWatch metrics show that CPU utilization rarely exceeds 30%. What is the MOST likely cause of the 503 errors?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Increase the size of the Auto Scaling group and adjust scaling policies.. Increasing the size of the Auto Scaling group and adjusting scaling policies ensures sufficient capacity during traffic spikes, preventing the healthy host count from dropping to zero. Option A is wrong because instance refresh is for rolling updates, not for handling spikes. Option C is wrong because Reserved Instances do not add on-demand capacity. Option D is wrong because a larger Network Load Balancer does not address the root cause of insufficient EC2 capacity.

Answer

Enable EC2 instance refresh for the Auto Scaling group.

Answer

Purchase Reserved Instances for the existing EC2 fleet.

Answer

Replace the ALB with a larger Network Load Balancer.

Question 15

A company uses AWS Lambda to process events from an SQS queue. The Lambda function has a reserved concurrency of 5. During peak hours, messages are being backed up in the queue. The function's duration is well within the 15-minute limit. What is the fastest way to increase throughput?

Accepted Answer

Increase the reserved concurrency to 20.. Increasing the reserved concurrency to 20 allows more Lambda functions to run simultaneously, enabling more messages to be processed in parallel. This is the fastest way to increase throughput because it directly increases the number of concurrent executions handling messages from the SQS queue. Option A is incorrect because Lambda does not have a configurable maximum thread count. Option C is incorrect because the SQS batch size is limited to a maximum of 10, not 100. Option D is incorrect because creating additional queues would require significant application changes and does not directly increase the processing capacity of the existing Lambda function.

Answer

Increase the function's maximum thread count.

Answer

Create additional SQS queues and distribute messages.

Answer

Increase the SQS batch size to 100.