A company wants to improve its ecommerce website on AWS. A database specialist decides to add Amazon ElastiCache for Redis in the implementation stack to ease the workload off the database and shorten the website response times. The database specialist must also ensure the ecommerce website is highly available within the company's AWS Region.
How should the database specialist deploy ElastiCache to meet this requirement?

1. A. Launch an ElastiCache for Redis cluster using the AWS CLI with the -cluster-enabled switch.
2. B. Launch an ElastiCache for Redis cluster and select read replicas in different Availability Zones.
3. C. Launch two ElastiCache for Redis clusters in two different Availability Zone
4. D. Configure Redis streams to replicate the cache from the primary cluster to another.
5. E. Launch an ElastiCache cluster in the primary Availability Zone and restore the cluster's snapshot to a different Availability Zone during disaster recovery.

Correct Answer: B
https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/AutoFailover.html
You can enable Multi-AZ only on Redis (cluster mode disabled) clusters that have at least one available read replica. Clusters without read replicas do not provide high availability or fault tolerance.

A company has an application that uses an Amazon DynamoDB table as its data store. During normal business days, the throughput requirements from the application are uniform and consist of 5 standard write calls per second to the DynamoDB table. Each write call has 2 KB of data.
For 1 hour each day, the company runs an additional automated job on the DynamoDB table that makes 20 write requests per second. No other application writes to the DynamoDB table. The DynamoDB table does not have to meet any additional capacity requirements.
How should a database specialist configure the DynamoDB table's capacity to meet these requirements MOST cost-effectively?

1. A. Use DynamoDB provisioned capacity with 5 WCUs and auto scaling.
2. B. Use DynamoDB provisioned capacity with 5 WCUs and a write-through cache that DynamoDB Accelerator (DAX) provides.
3. C. Use DynamoDB provisioned capacity with 10 WCUs and auto scaling.
4. D. Use DynamoDB provisioned capacity with 10 WCUs and no auto scaling.

Correct Answer: C
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadWriteCapacityMode.h

A company is running an on-premises application comprised of a web tier, an application tier, and a MySQL database tier. The database is used primarily during business hours with random activity peaks throughout the day. A database specialist needs to improve the availability and reduce the cost of the MySQL database tier as part of the company’s migration to AWS.
Which MySQL database option would meet these requirements?

1. A. Amazon RDS for MySQL with Multi-AZ
2. B. Amazon Aurora Serverless MySQL cluster
3. C. Amazon Aurora MySQL cluster
4. D. Amazon RDS for MySQL with read replica

Correct Answer: C

A company is concerned about the cost of a large-scale, transactional application using Amazon DynamoDB that only needs to store data for 2 days before it is deleted. In looking at the tables, a Database Specialist notices that much of the data is months old, and goes back to when the application was first deployed.
What can the Database Specialist do to reduce the overall cost?

1. A. Create a new attribute in each table to track the expiration time and create an AWS Glue transformation to delete entries more than 2 days old.
2. B. Create a new attribute in each table to track the expiration time and enable DynamoDB Streams on each table.
3. C. Create a new attribute in each table to track the expiration time and enable time to live (TTL) on each table.
4. D. Create an Amazon CloudWatch Events event to export the data to Amazon S3 daily using AWS Data Pipeline and then truncate the Amazon DynamoDB table.

Correct Answer: C
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html

A gaming company is designing a mobile gaming app that will be accessed by many users across the globe. The company wants to have replication and full support for multi-master writes. The company also wants to ensure low latency and consistent performance for app users.
Which solution meets these requirements?

1. A. Use Amazon DynamoDB global tables for storage and enable DynamoDB automatic scaling
2. B. Use Amazon Aurora for storage and enable cross-Region Aurora Replicas
3. C. Use Amazon Aurora for storage and cache the user content with Amazon ElastiCache
4. D. Use Amazon Neptune for storage

Correct Answer: A