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

Question 1

Multiple EC2 instances in different Availability Zones need concurrent read/write access to the same shared files. The files are actively modified by several application servers, and low-latency metadata operations matter more than extremely high aggregate throughput. Which two changes should the team make? Select two.

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

Accepted Answer

Use Amazon EFS instead of EBS or S3 for the shared file system.. Amazon EFS provides a fully managed, POSIX-compliant, shared file system that can be mounted concurrently by multiple EC2 instances across different Availability Zones (AZs). It supports concurrent read/write access with strong consistency, and its metadata operations are optimized for low latency, making it ideal for workloads where many application servers actively modify the same files. EBS cannot be shared across AZs, and S3 lacks POSIX semantics and low-latency metadata operations.

Answer

Use a single EBS Multi-Attach volume mounted read/write by all instances across AZs.

Answer

Store the files in S3 and mount them directly through the console as a shared network filesystem.

Answer

Place the files on instance store volumes so each server has faster local access.

Question 2

A nightly video rendering pipeline runs on Linux EC2 instances and is compatible with ARM64. The jobs are CPU-bound, checkpoint frequently, and can resume if interrupted. The business wants the best throughput per dollar for the batch window. Which two changes should the team make? Select two.

Accepted Answer

Use AWS Graviton-based instances for the render workers.. AWS Graviton-based instances use ARM64 architecture, which is explicitly compatible with the video rendering pipeline. They offer up to 40% better price-performance compared to comparable x86 instances for CPU-bound workloads, directly improving throughput per dollar. This makes option A correct for maximizing cost efficiency.

Answer

Use a single large x86 instance with On-Demand pricing to avoid interruptions.

Answer

Replace the batch workers with a Lambda function to eliminate instance management.

Answer

Move the workload to a spread placement group to increase cost efficiency.

Question 3

A global video platform serves mostly static images and JavaScript files from an S3 origin. Users in distant countries report slow load times. What should improve performance most?

Accepted Answer

Amazon CloudFront distribution with the S3 bucket as origin. Amazon CloudFront is a content delivery network (CDN) that caches static content (images, JavaScript) at edge locations worldwide. By distributing content closer to users, it reduces latency and improves load times significantly compared to serving directly from a single S3 origin. This is the most effective solution for a global user base accessing static assets.

Answer

A larger S3 bucket

Answer

RDS read replicas

Answer

An EC2 Auto Scaling group in one Region

Question 4

A DynamoDB table for a retail API has a partition key based only on the current date. Write throttling occurs during business hours. What is the best design change?

Accepted Answer

Use a higher-cardinality partition key that distributes writes across partitions. Using a partition key based solely on the current date creates a 'hot partition' because all writes for that day target the same partition, leading to throttling. A higher-cardinality partition key (e.g., combining date with a unique attribute like user ID or order ID) distributes write traffic evenly across multiple partitions, allowing DynamoDB to utilize its full throughput capacity and eliminating throttling.

Answer

Create a global secondary index with the same date key

Answer

Reduce the table's write capacity

Answer

Move the table to S3 Glacier Instant Retrieval

Question 5

A Lambda-based travel booking site has unpredictable traffic spikes and users see latency caused by cold starts. The function must respond consistently during expected campaign windows. What should be configured?

Accepted Answer

Provisioned concurrency during campaign windows. Provisioned concurrency initializes a specified number of execution environments in advance, eliminating cold starts for those instances. During campaign windows, this ensures consistent sub‑millisecond latency because the function is always warm and ready to handle requests immediately.

Answer

A larger deployment package

Answer

CloudTrail data events

Answer

Reserved concurrency only

Question 6

A retail API uses EC2 instances behind an ALB. CPU is consistently high during peak traffic, and request latency rises. What should be configured?

Accepted Answer

Auto Scaling policy based on an appropriate CloudWatch metric. An Auto Scaling policy based on an appropriate CloudWatch metric (such as CPUUtilization or ALBRequestCountPerTarget) dynamically adds or removes EC2 instances to match demand. This directly addresses the high CPU and rising latency by distributing the load across more instances, preventing performance degradation during peak traffic.

Answer

S3 Object Lock

Answer

A VPC endpoint for CloudWatch only

Answer

Disable health checks

Question 7

A high-volume analytics dashboard writes streaming click events that must be processed by multiple independent consumers. Which service is most appropriate?

Accepted Answer

Amazon Kinesis Data Streams. Amazon Kinesis Data Streams is the most appropriate service because it is designed for real-time streaming data ingestion and can be consumed by multiple independent consumers in parallel. Each shard within a Kinesis stream supports up to 5 read transactions per second and a total data read rate of 2 MB per second, allowing multiple consumer applications to process the same stream of click events concurrently without interfering with each other.

Answer

Amazon Route 53

Answer

Amazon EBS

Answer

AWS DataSync

Question 8

A telemetry pipeline uses RDS MySQL and receives many read-only reporting queries that slow down the primary database. What should the architect add?

Accepted Answer

RDS read replica and route reporting queries to it. RDS Read Replicas are designed specifically to offload read-heavy workloads from the primary database. By creating a read replica and routing the reporting queries to it, the primary database is freed from processing these read-only queries, reducing contention and improving overall performance. This is the most cost-effective and architecturally appropriate solution for read scaling in RDS MySQL.

Answer

Multi-AZ standby and route reads to the standby

Answer

S3 lifecycle policy

Answer

A larger NAT gateway

Question 9

A document portal requires consistent high IOPS for a transactional database on EC2. Which EBS volume type is most suitable?

Accepted Answer

Provisioned IOPS SSD such as io2. Provisioned IOPS SSD (io2) is the correct choice because it delivers consistent, high IOPS performance required for transactional databases running on EC2. io2 volumes offer a 99.999% durability and can sustain up to 256,000 IOPS per volume, making them ideal for latency-sensitive workloads like OLTP databases.

Answer

sc1 Cold HDD

Answer

Instance store only

Answer

st1 Throughput Optimized HDD

Question 10

A mobile game backend uses Amazon Aurora. The workload has many short-lived database connections from Lambda functions, causing connection storms. What should be added?

Accepted Answer

RDS Proxy. RDS Proxy is the correct solution because it sits between Lambda functions and the Aurora database, pooling and reusing database connections. This prevents connection storms by reducing the overhead of establishing new connections for each short-lived Lambda invocation, and it also helps manage IAM authentication for Lambda functions without storing database credentials.

Answer

An internet gateway

Answer

S3 Select

Answer

A larger Route 53 hosted zone

Question 11

A travel booking site uses EC2 instances behind an ALB. CPU is consistently high during peak traffic, and request latency rises. What should be configured?

Accepted Answer

Auto Scaling policy based on an appropriate CloudWatch metric. An Auto Scaling policy based on a CloudWatch metric like CPUUtilization or request latency directly addresses the root cause: rising CPU and latency under peak traffic. By automatically adding EC2 instances when the metric breaches a threshold, the ALB can distribute load across more resources, reducing CPU per instance and improving response times. This is the standard AWS solution for dynamic scaling to maintain performance.

Answer

A VPC endpoint for CloudWatch only

Answer

S3 Object Lock

Answer

Disable health checks

Question 12

A high-volume telemetry pipeline writes streaming click events that must be processed by multiple independent consumers. Which service is most appropriate?

Accepted Answer

Amazon Kinesis Data Streams. Amazon Kinesis Data Streams is the most appropriate service because it is designed for real-time streaming data ingestion and processing. It can capture and store terabytes of data per hour from hundreds of thousands of sources, such as click events, and allows multiple independent consumers to read and process the same stream concurrently using the Kinesis Client Library (KCL) or enhanced fan-out with dedicated throughput.

Answer

AWS DataSync

Answer

Amazon EBS

Answer

Amazon Route 53

Question 13

A DynamoDB table for a travel booking site has a partition key based only on the current date. Write throttling occurs during business hours. What is the best design change? The design must avoid adding custom operational scripts.

Accepted Answer

Use a higher-cardinality partition key that distributes writes across partitions. Using a low-cardinality partition key like the current date causes all writes to land on a single partition, leading to throttling. By designing a higher-cardinality key (e.g., combining date with a random suffix or user ID), writes are distributed evenly across partitions, fully utilizing the provisioned write capacity without custom scripts.

Answer

Create a global secondary index with the same date key

Answer

Move the table to S3 Glacier Instant Retrieval

Answer

Reduce the table's write capacity

Question 14

A read-heavy media archive repeatedly queries the same product catalogue data from DynamoDB with millisecond latency requirements. Which service can reduce read latency and table load? The design must avoid adding custom operational scripts.

Accepted Answer

DynamoDB Accelerator (DAX). DynamoDB Accelerator (DAX) is an in-memory cache for DynamoDB that delivers microsecond read latency, reducing the load on the underlying DynamoDB tables by serving repeated queries from its cache. This directly addresses the read-heavy media archive's millisecond latency requirements without requiring custom operational scripts, as DAX is fully managed and integrates seamlessly with existing DynamoDB API calls.

Answer

Amazon Kinesis Data Firehose

Answer

AWS Glue Data Catalog

Answer

S3 Transfer Acceleration

Question 15

A analytics dashboard uses an Application Load Balancer in one Region. Global users need lower network latency to the application without caching dynamic responses. What should be considered? The design must avoid adding custom operational scripts.

Accepted Answer

AWS Global Accelerator. AWS Global Accelerator uses the AWS global network to route traffic from edge locations to the optimal regional endpoint, reducing latency and jitter for global users. It does not cache content, making it ideal for dynamic responses that cannot be cached. The service requires no custom scripts, as it integrates directly with the Application Load Balancer via a static IP address or DNS name.

Answer

S3 Cross-Region Replication

Answer

AWS Backup cross-Region copy

Answer

CloudFront only with long TTLs