An online retail company is planning a multi-day flash sale that must support processing of up to 5,000 orders per second. The number of orders and exact schedule for the sale will vary each day. During the sale, approximately 10,000 concurrent users will look at the deals before buying items. Outside of the sale, the traffic volume is very low. The acceptable performance for read/write queries should be under 25 ms. Order items are about 2 KB in size and have a unique identifier. The company requires the most cost-effective solution that will automatically scale and is highly available.
Which solution meets these requirements?

1. A. Amazon DynamoDB with on-demand capacity mode
2. B. Amazon Aurora with one writer node and an Aurora Replica with the parallel query feature enabled
3. C. Amazon DynamoDB with provisioned capacity mode with 5,000 write capacity units (WCUs) and 10,000 read capacity units (RCUs)
4. D. Amazon Aurora with one writer node and two cross-Region Aurora Replicas

Correct Answer: A
The number of orders and exact schedule for the sale will vary each day. During the sale, approximately 10,000 concurrent users will look at the deals before buying items. Outside of the sale, the traffic volume is very low ==> Setting provisioning DynamoDB fix read 5000/write 10000 with will waste the resource when the traffic is low. It is not cost-effective.

An information management services company is storing JSON documents on premises. The company is using a MongoDB 3.6 database but wants to migrate to AWS. The solution must be compatible, scalable, and fully managed. The solution also must result in as little downtime as possible during the migration.
Which solution meets these requirements?

1. A. Create an AWS Database Migration Service (AWS DMS) replication instance, a source endpoint for MongoDB, and a target endpoint of Amazon DocumentDB (with MongoDB compatibility).
2. B. Create an AWS Database Migration Service (AWS DMS) replication instance, a source endpoint for MongoDB, and a target endpoint of a MongoDB image that is hosted on Amazon EC2
3. C. Use the mongodump and mongorestore tools to migrate the data from the source MongoDB deployment to Amazon DocumentDB (with MongoDB compatibility).
4. D. Use the mongodump and mongorestore tools to migrate the data from the source MongoDB deployment to a MongoDB image that is hosted on Amazon EC2.

Correct Answer: A
https://docs.aws.amazon.com/documentdb/latest/developerguide/docdb-migration.html#docdb-migration-approa

A company is using an Amazon ElastiCache for Redis cluster to host its online shopping website. Shoppers receive the following error when the website's application queries the cluster:

Which solutions will resolve this memory issues with the LEAST amount of effort? (Choose three.)

1. A. Reduce the TTL value for keys on the node.
2. B. Choose a larger node type.
3. C. Test different values in the parameter group for the maxmemory-policy parameter to find the ideal value to use.
4. D. Increase the number of nodes.
5. E. Monitor the EngineCPUUtilization Amazon CloudWatch metri
6. F. Create an AWS Lambda function to delete keys on nodes when a threshold is reached.
7. G. Increase the TTL value for keys on the node.

Correct Answer: ABC
https://aws.amazon.com/premiumsupport/knowledge-center/oom-command-not-allowed-redis/

A company has a database fleet that includes an Amazon RDS for MySQL DB instance. During an audit, the company discovered that the data that is stored on the DB instance is unencrypted.
A database specialist must enable encryption for the DB instance. The database specialist also must encrypt all connections to the DB instance.
Which combination of actions should the database specialist take to meet these requirements? (Choose three.)

1. A. In the RDS console, choose €Enable encryption€ to encrypt the DB instance by using an AWS Key Management Service (AWS KMS) key.
2. B. Encrypt the read replica of the unencrypted DB instance by using an AWS Key Management Service (AWS KMS) ke
3. C. Fail over the read replica to the primary DB instance.
4. D. Create a snapshot of the unencrypted DB instanc
5. E. Encrypt the snapshot by using an AWS Key Management Service (AWS KMS) ke
6. F. Restore the DB instance from the encrypted snapsho
7. G. Delete the original DB instance.
8. H. Require SSL connections for applicable database user accounts.
9. I. Use SSL/TLS from the application to encrypt a connection to the DB instance.
10. J. Enable SSH encryption on the DB instance.

Correct Answer: ACE
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Overview.Encryption.html#Overview.Encryption.

A database specialist is responsible for an Amazon RDS for MySQL DB instance with one read replica. The DB instance and the read replica are assigned to the default parameter group. The database team currently runs test queries against a read replica. The database team wants to create additional tables in the read replica that will only be accessible from the read replica to benefit the tests.
Which should the database specialist do to allow the database team to create the test tables?

1. A. Contact AWS Support to disable read-only mode on the read replic
2. B. Reboot the read replic
3. C. Connect to the read replica and create the tables.
4. D. Change the read_only parameter to false (read_only=0) in the default parameter group of the read replic
5. E. Perform a reboot without failove
6. F. Connect to the read replica and create the tables using the local_only MySQL option.
7. G. Change the read_only parameter to false (read_only=0) in the default parameter grou
8. H. Reboot the read replic
9. I. Connect to the read replica and create the tables.
10. J. Create a new DB parameter grou
11. K. Change the read_only parameter to false (read_only=0). Associate the read replica with the new grou
12. L. Reboot the read replic
13. M. Connect to the read replica and create the tables.

Correct Answer: D
https://aws.amazon.com/premiumsupport/knowledge-center/rds-read-replica/