- (Topic 3)
A company uses a payment processing system that requires messages for a particular payment ID to be received in the same order that they were sent Otherwise, the payments might be processed incorrectly.
Which actions should a solutions architect take to meet this requirement? (Select TWO.)

1. A. Write the messages to an Amazon DynamoDB table with the payment ID as the partition key
2. B. Write the messages to an Amazon Kinesis data stream with the payment ID as the partition key.
3. C. Write the messages to an Amazon ElastiCache for Memcached cluster with the payment ID as the key
4. D. Write the messages to an Amazon Simple Queue Service (Amazon SQS) queue Set the message attribute to use the payment ID
5. E. Write the messages to an Amazon Simple Queue Service (Amazon SQS) FIFO queu
6. F. Set the message group to use the payment ID.

Correct Answer: BE
1) SQS FIFO queues guarantee that messages are received in the exact order they are sent. Using the payment ID as the message group ensures all messages for a payment ID are received sequentially. 2) Kinesis data streams can also enforce ordering on a per partition key basis. Using the payment ID as the partition key will ensure strict ordering of messages for each payment ID.

- (Topic 4)
A company's website hosted on Amazon EC2 instances processes classified data stored in Amazon S3 Due to security concerns, the company requires a pnvate and secure connection between its EC2 resources and Amazon S3.
Which solution meets these requirements?

1. A. Set up S3 bucket policies to allow access from a VPC endpomt.
2. B. Set up an 1AM policy to grant read-write access to the S3 bucket.
3. C. Set up a NAT gateway to access resources outside the private subnet.
4. D. Set up an access key ID and a secret access key to access the S3 bucket.

Correct Answer: A
This solution meets the following requirements:
✑ It is private and secure, as it allows the EC2 instances to access the S3 bucket
without using the public internet. A VPC endpoint is a gateway that enables you to create a private connection between your VPC and another AWS service, such as S3, within the same Region. A VPC endpoint for S3 provides secure and direct access to S3 buckets and objects using private IP addresses from your VPC. You can also use VPC endpoint policies and S3 bucket policies to control the access to the S3 resources based on the endpoint, the IAM user, the IAM role, or the source IP address.
✑ It is simple and scalable, as it does not require any additional AWS services,
gateways, or NAT devices. A VPC endpoint for S3 is a fully managed service that scales automatically with the network traffic. You can create a VPC endpoint for S3 with a few clicks in the VPC console or with a simple API call. You can also use the same VPC endpoint to access multiple S3 buckets in the same Region.
References:
✑ VPC Endpoints - Amazon Virtual Private Cloud
✑ Gateway VPC endpoints - Amazon Virtual Private Cloud
✑ Using Amazon S3 with interface VPC endpoints - Amazon Simple Storage Service
✑ Using Amazon S3 with gateway VPC endpoints - Amazon Simple Storage Service

- (Topic 1)
A company runs an on-premises application that is powered by a MySQL database The company is migrating the application to AWS to Increase the application's elasticity and availability
The current architecture shows heavy read activity on the database during times of normal operation Every 4 hours the company's development team pulls a full export of the production database to populate a database in the staging environment During this period, users experience unacceptable application latency The development team is unable to use the staging environment until the procedure completes
A solutions architect must recommend replacement architecture that alleviates the application latency issue The replacement architecture also must give the development team the ability to continue using the staging environment without delay
Which solution meets these requirements?

1. A. Use Amazon Aurora MySQL with Multi-AZ Aurora Replicas for productio
2. B. Populate the staging database by implementing a backup and restore process that uses the mysqldump utility.
3. C. Use Amazon Aurora MySQL with Multi-AZ Aurora Replicas for production Use database cloning to create the staging database on-demand
4. D. Use Amazon RDS for MySQL with a Mufti AZ deployment and read replicas for production Use the standby instance tor the staging database.
5. E. Use Amazon RDS for MySQL with a Multi-AZ deployment and read replicas for productio
6. F. Populate the staging database by implementing a backup and restore process that uses the mysqldump utility.

Correct Answer: B
https://aws.amazon.com/blogs/aws/amazon-aurora-fast-database-cloning/

- (Topic 3)
A company is deploying a two-tier web application in a VPC. The web tier is using an Amazon EC2 Auto Scaling group with public subnets that span multiple Availability Zones. The database tier consists of an Amazon RDS for MySQL DB instance in separate private subnets. The web tier requires access to the database to retrieve product information.
The web application is not working as intended. The web application reports that it cannot connect to the database. The database is confirmed to be up and running. All configurations for the network ACLs. security groups, and route tables are still in their default states.
What should a solutions architect recommend to fix the application?

1. A. Add an explicit rule to the private subnet's network ACL to allow traffic from the web tier's EC2 instances.
2. B. Add a route in the VPC route table to allow traffic between the web tier's EC2 instances and Ihe database tier.
3. C. Deploy the web tier's EC2 instances and the database tier's RDS instance into two separate VPC
4. D. and configure VPC peering.
5. E. Add an inbound rule to the security group of the database tier's RDS instance to allow traffic from the web tier's security group.

Correct Answer: D
This answer is correct because it allows the web tier to access the database tier by using
security groups as a source, which is a recommended best practice for VPC connectivity. Security groups are stateful and can reference other security groups in the same VPC, which simplifies the configuration and maintenance of the firewall rules. By adding an inbound rule to the database tier’s security group, the web tier’s EC2 instances can connect to the RDS instance on port 3306, regardless of their IP addresses or subnets. References:
✑ Security groups - Amazon Virtual Private Cloud
✑ Best practices and reference architectures for VPC design

- (Topic 3)
A company hostss a three application on Amazon EC2 instances in a single Availability Zone. The web application uses a self-managed MySQL database that is hosted on an EC2 instances to store data in an Amazon Elastic Block Store (Amazon EBS) volumn. The MySQL database currently uses a 1 TB Provisioned IOPS SSD (io2) EBS volume. The company expects traffic of 1,000 IOPS for both reads and writes at peak traffic.
The company wants to minimize any distruptions, stabilize perperformace, and reduce costs while retaining the capacity for double the IOPS. The company wants to more the database tier to a fully managed solution that is highly available and fault tolerant.
Which solution will meet these requirements MOST cost-effectively?

1. A. Use a Multi-AZ deployment of an Amazon RDS for MySQL DB instance with an io2 Block Express EBS volume.
2. B. Use a Multi-AZ deployment of an Amazon RDS for MySQL DB instance with a General Purpose SSD (gp2) EBS volume.
3. C. Use Amazon S3 Intelligent-Tiering access tiers.
4. D. Use two large EC2 instances to host the database in active-passive mode.

Correct Answer: B
RDS supported Storage > https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_Storage.html GP2 max IOPS > https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/general- purpose.html#gp2-performance
Amazon RDS provides three storage types: General Purpose SSD (also known as gp2 and gp3), Provisioned IOPS SSD (also known as io1), and magnetic (also known as standard). They differ in performance characteristics and price, which means that you can tailor your storage performance and cost to the needs of your database workload. You can create MySQL, MariaDB, Oracle, and PostgreSQL RDS DB instances with up to 64 tebibytes (TiB) of storage. You can create SQL Server RDS DB instances with up to 16 TiB of storage. For this amount of storage, use the Provisioned IOPS SSD and General Purpose SSD storage types. https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_Storage.html