Amazon Web Services Updated SAA-C03 Exam Questions and Answers by ryder

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.

This option is the most efficient because it uses Amazon SQS, which is a fully managed message queuing service that lets you send, store, and receive messages between software components at any volume, without losing messages or requiring other services to be available1. It also uses an SQS message queue to asynchronously dispatch requests to the different application tiers, which decouples the image upload process from the thumbnail generation process and enables scalability and reliability. It also alerts the user through an application message that the image was received, which provides a faster response time to the user than waiting for the thumbnail generation to complete. Option A is less efficient because it uses a custom AWS Lambda function to generate the thumbnail and alert the user, which is a way to run code without provisioning or managing servers. However, this does not use an asynchronous dispatch mechanism to separate the image upload process from the thumbnail generation process. It also uses the image upload process as an event source to invoke the Lambda function, which could cause concurrency issues if there are many images uploaded at once. Option B is less efficient because it uses AWS Step Functions, whichis a fully managed service that provides a graphical console to arrange and visualize the components of your application as a series of steps2. However, this does not use an asynchronous dispatch mechanism to separate the image upload process from the thumbnail generation process. It also uses Step Functions to handle the orchestration between the application tiers and alert the user when thumbnail generation is complete, which could introduce additional complexity and latency. Option D is less efficient because it uses Amazon SNS, which is a fully managed messaging service that enables you to send messages or notifications directly to users with SMS text messages or email3. However, this does not use an asynchronous dispatch mechanism to separate the image upload process from the thumbnail generation process. It also uses SNS notification topics and subscriptions to generate the thumbnail after the image upload is complete and message the user’s mobile app by way of a push notification after thumbnail generation is complete, which could introduce additional complexity and latency.

This answer is correct because it provides a resilient and durable replacement for the on-premises file share that is compatible with a serverless web application. Amazon S3 is a fully managed object storage service that can store any amount of data and serve it over the internet. It supports the following features:

Resilience: Amazon S3 stores data across multiple Availability Zones within a Region, and offers 99.999999999% (11 9’s) of durability. It also supports cross-region replication, which enables automatic and asynchronous copying of objects across buckets in different AWS Regions.

Durability: Amazon S3 encrypts data at rest using server-side encryption with either Amazon S3-managed keys (SSE-S3), AWS KMS keys (SSE-KMS), or customer-provided keys (SSE-C). It also supports encryption in transit using SSL/TLS. Amazon S3 also provides data protection features such as versioning, which keeps multiple versions of an object in the same bucket, and MFA Delete, which requires additional authentication for deleting an object version or changing the versioning state of a bucket.

Performance: Amazon S3 delivers high performance and scalability for serving static and dynamic web content. It also supports features such as S3 Transfer Acceleration, which speeds up data transfers by routing requests to AWS edge locations, and S3 Select, which enables retrieving only a subset of data from an object by using simple SQL expressions.

The S3 Standard-Infrequent Access (S3 Standard-IA) storage class is suitable for storing images that are rarely accessed, but must be immediately available when needed. It offers the same high durability, throughput, and low latency as S3 Standard, but with a lower storage cost per GB and a higher per-request cost.

• Launching instances within a single AZ and using a cluster placement group provides the lowest network latency and highest bandwidth between instances. This maximizes performance for an in-memory database and high-throughput application.

• Communications between instances in the same AZ and placement group are free, minimizing data transfer charges. Inter-AZ and public IP traffic can incur charges.

• A cluster placement group enables the instances to be placed close together within the AZ, allowing the high network throughput required. Partition groups span AZs, reducing bandwidth.

• Auto Scaling across zones could launch instances in AZs that increase data transfer charges. It may reduce network throughput, impacting performance.