- (Exam Topic 1)
A company has migrated an application from on premises to AWS. The application frontend is a static website that runs on two Amazon EC2 instances behind an Application Load Balancer (ALB). The application backend is a Python application that runs on three EC2 instances behind another ALB. The EC2 instances are large, general purpose On-Demand Instances that were sized to meet the on-premises specifications for peak usage of the application.
The application averages hundreds of thousands of requests each month. However, the application is used mainly during lunchtime and receives minimal traffic during the rest of the day.
A solutions architect needs to optimize the infrastructure cost of the application without negatively affecting the application availability.
Which combination of steps will meet these requirements? (Choose two.)

1. A. Change all the EC2 instances to compute optimized instances that have the same number of cores as the existing EC2 instances.
2. B. Move the application frontend to a static website that is hosted on Amazon S3.
3. C. Deploy the application frontend by using AWS Elastic Beanstal
4. D. Use the same instance type for the nodes.
5. E. Change all the backend EC2 instances to Spot Instances.
6. F. Deploy the backend Python application to general purpose burstable EC2 instances that have the same number of cores as the existing EC2 instances.

Correct Answer: BD
Moving the application frontend to a static website that is hosted on Amazon S3 will save cost as S3 is cheaper than running EC2 instances.
Using Spot instances for the backend EC2 instances will also save cost, as they are significantly cheaper than On-Demand instances. This will be suitable for the application, as it has minimal traffic during the rest of the day, and the availability of spot instances will not negatively affect the application's availability.
Reference:
Amazon S3 pricing: https://aws.amazon.com/s3/pricing/
Amazon EC2 Spot Instances documentation: https://aws.amazon.com/ec2/spot/ AWS Elastic Beanstalk documentation: https://aws.amazon.com/elasticbeanstalk/ Amazon Elastic Compute Cloud (EC2) pricing: https://aws.amazon.com/ec2/pricing/

- (Exam Topic 3)
A company has a solution that analyzes weather data from thousands of weather stations. The weather stations send the data over an Amazon API Gateway REST API that has an AWS Lambda function integration. The Lambda function calls a third-party service for data pre-processing. The third-party service gets overloaded and fails the pre-processing, causing a loss of data.
A solutions architect must improve the resiliency of the solution. The solutions architect must ensure that no data is lost and that data can be processed later if failures occur.
What should the solutions architect do to meet these requirements?

1. A. Create an Amazon Simple Queue Service (Amazon SQS) queu
2. B. Configure the queue as the dead-letter queue for the API.
3. C. Create two Amazon Simple Queue Service (Amazon SQS) queues: a primary queue and a secondary queu
4. D. Configure the secondary queue as the dead-letter queue for the primary queu
5. E. Update the API to use a new integration to the primary queu
6. F. Configure the Lambda function as the invocation target for the primary queue.
7. G. Create two Amazon EventBridge event buses: a primary event bus and a secondary event bu
8. H. Update the API to use a new integration to the primary event bu
9. I. Configure an EventBridge rule to react to all events on the primary event bu
10. J. Specify the Lambda function as the target of the rul
11. K. Configure thesecondary event bus as the failure destination for the Lambda function.
12. L. Create a custom Amazon EventBridge event bu
13. M. Configure the event bus as the failure destination for the Lambda function.

Correct Answer: C
This option allows the solution to decouple the API from the Lambda function and use EventBridge as an event-driven service that can handle failures gracefully1. By using two event buses, one for normal events and one for failed events, the solution can ensure that no data is lost and that data can be processed later if failures occur2. The primary event bus receives the data from the weather stations through
the API integration and triggers the Lambda function through a rule. The Lambda function can then call the
third-party service for data pre-processing. If the third-party service fails, the Lambda function can send an error response to EventBridge, which will route it to the secondary event bus as a failure destination3. The secondary event bus can then store the failed events in another service, such as Amazon S3 or Amazon SQS, for troubleshooting or reprocessing.
References:
Using Amazon EventBridge with AWS Lambda
Using multiple event buses
Using failure destinations
[Using dead-letter queues]
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- (Exam Topic 2)
A company has loT sensors that monitor traffic patterns throughout a large city. The company wants to read and collect data from the sensors and perform aggregations on the data.
A solutions architect designs a solution in which the loT devices are streaming to Amazon Kinesis Data Streams. Several applications are reading from the stream. However, several consumers are experiencing throttling and are periodically and are periodically encountering a RealProvisioned Throughput Exceeded error.
Which actions should the solution architect take to resolve this issue? (Select THREE.)

1. A. Reshard the stream to increase the number of shards s in the stream.
2. B. Use the Kinesis Producer Library KPL). Adjust the polling frequency.
3. C. Use consumers with the enhanced fan-out feature.
4. D. Reshard the stream to reduce the number of shards in the stream.
5. E. Use an error retry and exponential backoff mechanism in the consumer logic.
6. F. Configure the stream to use dynamic partitioning.

Correct Answer: ACE
https://repost.aws/knowledge-center/kinesis-readprovisionedthroughputexceeded Follow Data Streams best practices
To mitigate ReadProvisionedThroughputExceeded exceptions, apply these best practices:
• Reshard your stream to increase the number of shards in the stream.
• Use consumers with enhanced fan-out. For more information about enhanced fan-out, see Developing custom consumers with dedicated throughput (enhanced fan-out).
• Use an error retry and exponential backoff mechanism in the consumer logic if ReadProvisionedThroughputExceeded exceptions are encountered. For consumer applications that use an AWS SDK, the requests are retried by default.

- (Exam Topic 2)
A company ingests and processes streaming market data. The data rate is constant. A nightly process that calculates aggregate statistics is run, and each execution takes about 4 hours to complete. The statistical analysis is not mission critical to the business, and previous data points are picked up on the next execution if a particular run fails.
The current architecture uses a pool of Amazon EC2 Reserved Instances with 1-year reservations running full time to ingest and store the streaming data in attached Amazon EBS volumes. On-Demand EC2 instances are launched each night to perform the nightly processing, accessing the stored data from NFS shares on the ingestion servers, and terminating the nightly processing servers when complete. The Reserved Instance reservations are expiring, and the company needs to determine whether to purchase new reservations or implement a new design.
Which is the most cost-effective design?

1. A. Update the ingestion process to use Amazon Kinesis Data Firehose to save data to Amazon S3. Use a scheduled script to launch a fleet of EC2 On-Demand Instances each night to perform the batch processing of the S3 dat
2. B. Configure the script to terminate the instances when the processing is complete.
3. C. Update the ingestion process to use Amazon Kinesis Data Firehose to save data to Amazon S3. Use AWS Batch with Spot Instances to perform nightlyprocessing with a maximum Spot price that is 50% of the On-Demand price.
4. D. Update the ingestion process to use a fleet of EC2 Reserved Instances with 3-year reservations behind a Network Load Balance
5. E. Use AWS Batch with SpotInstances to perform nightly processing with a maximum Spot price that is 50% of the On-Demand price.
6. F. Update the ingestion process to use Amazon Kinesis Data Firehose to save data to Amazon Redshift.Use Amazon EventBridge to schedule an AWS Lambdafunction to run nightly to query Amazon Redshift to generate the daily statistics.

Correct Answer: B
Updating the ingestion process to use Amazon Kinesis Data Firehose to save data to Amazon S3 will reduce the need for EC2 instances and EBS volumes for data storage1. Using AWS Batch with Spot Instances to perform nightly processing will leverage the cost savings of Spot Instances, which are up to 90% cheaper than On-Demand Instances2. AWS Batch will also handle the scheduling and scaling of the processing jobs. Setting the maximum Spot price to 50% of the On-Demand price will reduce the chances of interruption and ensure that the processing is cost-effective.

- (Exam Topic 1)
A retail company has structured its AWS accounts to be part of an organization in AWS Organizations. The company has set up consolidated billing and has mapped its departments to the following OUs: Finance. Sales. Human Resources The HR department is releasing a new system thai will launch in 3 months. In preparation, the HR department has purchased several Reserved Instances (RIs) in its production AWS account. The HR department will install the new application on this account. The HR department wants to make sure that other departments cannot share the Rl discounts.
Which solution will meet these requirements?

1. A. In the AWS Billing and Cost Management console for the HR department's production account, turn off R1 sharing.
2. B. Remove the HR department's production AWS account from the organizatio
3. C. Add the account to the consolidating billing configuration only.
4. D. In the AWS Billing and Cost Management console, use the organization's management account to turn off R1 sharing for the HR department's production AWS account.
5. E. Create an SCP in the organization to restrict access to the RI
6. F. Apply the SCP to the OUs of the other departments.

Correct Answer: C
You can use the management account of the organization in AWS Billing and Cost Management console to turn off RI sharing for the HR department's production AWS account. This will prevent other departments from sharing the RI discounts and ensure that only the HR department can use the RIs purchased in their production account.