SAA-C03 Design High-Performing Architectures Practice Test 21 — 15 Questions

Question 1

A company runs a web application on Amazon EC2 instances behind an Application Load Balancer. The application stores user-uploaded images in an Amazon S3 bucket. Users report slow image upload times, especially from mobile devices in remote locations. The solutions architect needs to improve upload performance for these users. Which action should the architect take?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Enable S3 Transfer Acceleration on the bucket and configure the application to use the accelerated endpoint for uploads.. S3 Transfer Acceleration leverages CloudFront edge locations to accelerate uploads to S3. Data is uploaded to the nearest edge location and then transferred to S3 over the optimized AWS network. This reduces latency and improves throughput for users far from the bucket's Region, making it the right choice for slow image uploads from remote mobile devices.

Answer

Configure the S3 bucket for cross-region replication to a bucket in a region closer to the users.

Answer

Use Amazon CloudFront with a custom origin pointing to the S3 bucket to cache uploads.

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Increase the size of the EC2 instances to improve their network bandwidth for handling uploads.

Question 2

A solutions architect is designing a high-performance architecture for a real-time analytics application. The application ingests a continuous stream of data from thousands of IoT devices. The data must be processed in near real-time, and the results must be stored in a durable, scalable data store for later analysis. The architect needs to choose AWS services that can handle the ingestion and processing of the stream. (Choose two.)

Accepted Answer

Use Amazon Kinesis Data Streams to ingest the data.. Amazon Kinesis Data Streams provides a scalable, durable ingestion layer for real-time streaming data, capable of handling thousands of IoT devices. AWS Lambda can be integrated as a consumer to process records in near real-time, automatically scaling with the stream. Together, they form a serverless pipeline that ingests and processes data with low latency, and can write results to a durable store like S3 or DynamoDB.

Answer

Use AWS Glue to process the stream in real time.

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Use Amazon Redshift to ingest the data directly from the devices.

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Use Amazon SQS FIFO queues to ingest the data.

Question 3

A company runs a microservices application on Amazon ECS with AWS Fargate. The services communicate over HTTP/2 and gRPC. The architect needs to implement service-to-service communication that provides high throughput, low latency, and mutual TLS encryption. The solution must also support traffic splitting for canary deployments. Which approach should the architect take?

Accepted Answer

Deploy an AWS App Mesh virtual service with Envoy proxies sidecar containers, and configure routes with weights for canary deployments.. AWS App Mesh is a service mesh that uses Envoy proxies to manage service-to-service communication. It supports HTTP/2 and gRPC, provides mutual TLS for encryption, and allows weighted routing for canary deployments. This makes it the best fit for the requirements of high throughput, low latency, mTLS, and traffic splitting in an ECS on Fargate environment.

Answer

Use an Application Load Balancer with gRPC support and configure multiple target groups with weighted routing.

Answer

Use Amazon API Gateway with private integration to the ECS services, and enable mutual TLS on the API Gateway.

Answer

Configure AWS Cloud Map for service discovery and use security groups to enforce encryption between tasks.

Question 4

A startup runs a static website hosted on Amazon S3. The website is accessed globally, and users in Europe report slow load times. The company wants to improve performance for these users without changing the website's code. Which AWS service should the company use?

Accepted Answer

Amazon CloudFront with an S3 origin.. CloudFront caches static content at edge locations worldwide, bringing it closer to users. For a static website on S3, creating a CloudFront distribution with the S3 bucket as the origin is the standard solution to reduce latency for global users. It requires no changes to the website code, only configuration of the distribution and updating DNS to point to CloudFront.

Answer

AWS Global Accelerator with an S3 endpoint.

Answer

AWS Direct Connect.

Answer

Amazon S3 Transfer Acceleration.

Question 5

A genomics company stores 400 TB of compressed reference data in Amazon S3. Researchers in an on-premises lab must run high-throughput reads of this data over a 10 Gbps AWS Direct Connect connection. The team observes that reads are slower than expected and wants to maximize throughput per S3 request while minimizing request costs. Which S3 feature should they implement?

Accepted Answer

S3 byte-range fetches using parallel GET requests against the same object.. Large-object throughput in S3 scales with concurrent connections, so issuing parallel byte-range GETs against each object saturates the Direct Connect link far better than a single sequential GET. Transfer Acceleration targets internet paths, replication moves copies without changing read mechanics, and Intelligent-Tiering is a cost tool rather than a throughput tool.

Answer

S3 Cross-Region Replication to a bucket in the lab's nearest Region.

Answer

S3 Transfer Acceleration on the bucket, because it speeds up long-distance transfers.

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S3 Intelligent-Tiering to automatically move frequently accessed data to a faster tier.

Question 6

A financial analytics company runs a nightly batch job that reads 4 TB of compressed log data from an Amazon S3 bucket and writes aggregated results to another S3 bucket. The job runs on a fleet of 8 Amazon EC2 instances in a single AWS Region, and the team wants the highest possible aggregate read throughput while minimizing request costs. The data is already stored in S3 Standard, and the team does not want to change the storage class. Which solution best meets these requirements?

Accepted Answer

Have the EC2 instances issue ranged GET requests against many distinct prefixes in parallel to spread the load across S3 partitions.. S3 scales read throughput by partitioning data across multiple internal partitions, each with its own request rate limit. Spreading parallel ranged GET requests across many prefixes lets the fleet hit multiple partitions simultaneously, maximizing aggregate throughput. Transfer Acceleration, S3 File Gateway, and Cross-Region Replication all add cost or complexity without addressing the per-prefix request limit for in-Region batch reads.

Answer

Enable S3 Cross-Region Replication to a second bucket and have half the instances read from the replica.

Answer

Use S3 Transfer Acceleration on the source bucket and have the EC2 instances read through the accelerated endpoint.

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Mount the source bucket as a file system on each EC2 instance using an S3 File Gateway and read the objects through the mounted share.

Question 7

A gaming company uses Amazon DynamoDB to store player session data. The table has a partition key of PlayerID and a sort key of SessionStartTime. The company needs to retrieve all sessions for a specific player within a date range, sorted by session start time. The table is large and the company wants to minimize read latency. Which approach should they use?

Accepted Answer

Perform a Query operation on the table using the partition key and a condition on the sort key.. The table's primary key already supports the required access pattern: partition key PlayerID and sort key SessionStartTime. A Query operation with a condition on the sort key retrieves exactly the items needed, sorted by session start time, with minimal latency. Scans, GSIs, and DAX do not provide a more efficient solution for this specific query.

Answer

Use DynamoDB Accelerator (DAX) to cache the results of a Scan operation.

Answer

Perform a Scan operation with a FilterExpression on PlayerID and SessionStartTime.

Answer

Create a global secondary index with PlayerID as the partition key and SessionStartTime as the sort key, then Query the index.

Question 8

A retail company runs a stateless web tier on Amazon EC2 instances behind an Application Load Balancer. During flash sales, response times spike because each request triggers many database queries. The team wants to reduce database load and improve read latency for product catalog pages that change only a few times per day. Which solution is MOST appropriate?

Accepted Answer

Deploy an Amazon ElastiCache for Redis cluster and cache the catalog query results.. Caching the catalog query results in ElastiCache for Redis removes most repeated database reads and serves product pages from memory, which directly cuts database load and read latency. DynamoDB migration is invasive, Performance Insights only diagnoses, and adding web instances increases pressure on the database rather than relieving it.

Answer

Add more EC2 instances to the web tier behind the load balancer.

Answer

Enable Amazon RDS Performance Insights and tune the slowest queries.

Answer

Move the catalog tables to Amazon DynamoDB with on-demand capacity.

Question 9

A healthcare company runs a patient portal on Amazon EC2 instances behind an Application Load Balancer. The application stores session state in memory on each instance, and users are being logged out when the load balancer routes them to a different instance. The company wants to keep the application stateless and avoid modifying application code. Which solution best meets these requirements?

Accepted Answer

Store session data in an Amazon ElastiCache for Redis cluster and have the instances read and write sessions there.. To keep an application stateless, session data must live outside the compute instances. ElastiCache for Redis provides a shared, low-latency session store that any instance can access, so users remain logged in regardless of which instance handles the request. Sticky sessions, warm pools, and cross-zone load balancing either mask the problem or address unrelated concerns without removing instance-local state.

Answer

Configure the Auto Scaling group to use a warm pool so that new instances inherit the session state from existing instances.

Answer

Enable sticky sessions on the Application Load Balancer using duration-based cookie stickiness.

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Enable cross-zone load balancing on the Application Load Balancer to ensure sessions are distributed evenly.

Question 10

A retail company is deploying a read-heavy product catalog on Amazon Aurora MySQL. The primary instance is heavily loaded with read traffic, and the team wants to offload reads to Aurora Replicas while keeping the application resilient to replica failures. The application connects using a single endpoint. Which two actions should the team take to meet these requirements? (Choose two.)

Accepted Answer

Enable Aurora Auto Scaling for the cluster so that Aurora Replicas are added or removed based on read workload.. Aurora separates the writer endpoint from the reader endpoint, and the reader endpoint automatically distributes connections across all Aurora Replicas. Pairing that endpoint with Aurora Auto Scaling lets the cluster add or remove replicas based on read demand, so the application gains both read offloading and resilience without custom failover logic. Direct instance endpoints, caching, and multi-master do not fulfill the specific goal of routing reads through replicas.

Answer

Configure the application to connect directly to each Aurora Replica by its individual instance endpoint and round-robin between them in code.

Answer

Create an Amazon ElastiCache for Memcached cluster and cache all product catalog queries there.

Answer

Convert the Aurora cluster to a multi-master cluster so that all instances accept writes and reads.

Question 11

A startup runs a static marketing website on Amazon S3 and wants to serve it to users worldwide with low latency. The site consists of HTML, CSS, JavaScript, and images stored in a single S3 bucket in the us-east-1 Region. The team wants to minimize cost while improving global performance. Which solution should the team implement?

Accepted Answer

Create an Amazon CloudFront distribution with the S3 bucket as the origin and use the default cache behavior.. CloudFront is the standard AWS service for delivering static content globally with low latency. It caches objects at edge locations, reducing the number of requests that reach the S3 origin and improving performance for users everywhere. Cross-Region Replication, EC2-hosted content, and Transfer Acceleration either add cost and complexity or do not provide edge caching, making them less suitable for this scenario.

Answer

Enable S3 Transfer Acceleration on the bucket and update the website URLs to use the accelerated endpoint.

Answer

Enable S3 Cross-Region Replication to replicate the bucket to multiple Regions and direct users to the closest bucket using latency-based routing.

Answer

Move the website content to an Amazon EBS volume attached to an EC2 instance in each Region and serve it with a web server.

Question 12

A data engineering team runs an Amazon EMR cluster that processes large datasets stored in Amazon S3. The cluster uses Amazon EBS volumes for temporary storage, and jobs frequently spill intermediate data to disk. The team notices that shuffle operations are slow and wants to improve performance without changing the data format or increasing the number of core nodes. Which change should the team make?

Accepted Answer

Replace the EBS volumes with instance store volumes and configure EMR to use them for shuffle and temporary data.. Shuffle-heavy EMR workloads benefit from fast local storage, and instance store volumes provide higher IOPS and lower latency than EBS. Configuring EMR to use instance store for shuffle and temporary data reduces spill time and improves job performance without adding core nodes or altering data formats. Managed scaling, larger EBS volumes, and S3-backed shuffle either do not address the local disk bottleneck or introduce additional latency.

Answer

Increase the size of the existing EBS volumes and enable EBS optimization on the core nodes.

Answer

Move the intermediate data to an Amazon S3 bucket and configure EMR to use S3 for shuffle storage.

Answer

Enable EMR managed scaling to automatically add task nodes during shuffle-heavy stages.

Question 13

A financial analytics firm runs a nightly batch job on a fleet of Amazon EC2 instances that read millions of small JSON objects from an Amazon S3 bucket and write aggregated results to another S3 bucket. The job currently takes over six hours and the team wants to reduce this time without modifying the application code. The S3 buckets are in the same AWS Region as the EC2 instances. Which action will most effectively improve the performance of the batch job?

Accepted Answer

Increase the number of EC2 instances and ensure the S3 keys are distributed across multiple prefixes.. The batch job's performance is constrained by the rate at which it can read and write objects to S3. S3 scales horizontally, but the achievable request rate depends on the number of distinct key prefixes and the level of concurrency. By adding more EC2 instances and distributing keys across multiple prefixes, the job can parallelize requests and fully utilize S3's scalability, dramatically reducing the six-hour runtime without modifying application logic.

Answer

Switch the batch job to use S3 Select to retrieve only the necessary fields from each JSON object.

Answer

Configure the EC2 instances to use S3 Transfer Acceleration for all requests.

Answer

Enable S3 Cross-Region Replication to a bucket in a different Region and redirect the job to the replica.

Question 14

A retail company runs a read-heavy product catalog on Amazon RDS for MySQL. During flash sales, read replicas lag behind the primary and the application serves stale prices. The team wants to scale read traffic while ensuring the application reads the most current data for price lookups. Which solution should a solutions architect recommend?

Accepted Answer

Route price lookups to the primary DB instance and other reads to read replicas.. RDS read replicas use asynchronous replication, so they can lag under write-heavy flash-sale conditions. Price lookups need the latest committed value, so sending them to the primary guarantees freshness, while other reads continue to use replicas for scale. Multi-AZ standbys cannot serve reads, and simply adding replica capacity does not eliminate lag, so routing consistency-sensitive queries to the primary is the correct design.

Answer

Enable Multi-AZ on the RDS for MySQL instance and point all reads to the standby.

Answer

Increase the size of the read replicas and enable automatic scaling of replicas.

Answer

Configure the application to retry reads on a replica until the price matches the primary.

Question 15

A company is deploying a new web application on AWS. The application will serve static content (HTML, CSS, JavaScript, images) and dynamic API requests. The company expects a global user base and wants to minimize latency for all users. The static content is stored in an Amazon S3 bucket, and the dynamic APIs are hosted on Amazon EC2 instances behind an Application Load Balancer. Which service should the company use to accelerate both static and dynamic content delivery?

Accepted Answer

Amazon CloudFront with the S3 bucket and ALB as origins. Amazon CloudFront is a global content delivery network that caches static content at edge locations and can also forward dynamic requests to an Application Load Balancer origin. By using CloudFront with both the S3 bucket and the ALB as origins, the company can accelerate delivery of static and dynamic content for a global user base, reducing latency and improving performance.

Answer

Amazon Route 53 with latency-based routing to multiple Regions

Answer

AWS Global Accelerator

Answer

AWS Direct Connect with a public virtual interface