SAA-C03 Timed Practice Test 4 — 10 Questions

Question 1

A worker service consumes messages from an Amazon SQS queue. Some messages are malformed and always fail validation. The worker retries, but it keeps reprocessing the same bad messages and consumes processing capacity that should be used for valid work. What is the best solution to prevent “poison messages” from blocking progress?

Accepted Answer

Configure a Dead-Letter Queue (DLQ) and set a redrive policy so messages move to the DLQ after a maximum number of receives.. A Dead-Letter Queue (DLQ) with a redrive policy is the standard AWS mechanism for handling poison messages. By setting a maximum receive count (e.g., 5), the SQS queue automatically moves messages that fail processing repeatedly to the DLQ, isolating them from the main queue. This prevents the worker from wasting capacity on invalid messages and allows the main queue to continue processing valid work without interruption.

Answer

Increase the visibility timeout so the worker gets fewer retries per hour.

Answer

Disable SQS retries by deleting messages immediately on any processing error.

Answer

Create a second worker that polls the queue less frequently until the malformed message is processed successfully.

Question 2

A test environment has EC2 instances that are oversized based on CPU, memory, and network utilisation. Which AWS service should identify rightsizing recommendations? The architecture review board prefers a managed AWS-native control.

Accepted Answer

AWS Compute Optimizer. AWS Compute Optimizer is a managed service that uses machine learning to analyze historical utilization metrics (CPU, memory, network, and storage) and provides rightsizing recommendations for EC2 instances. It identifies over-provisioned resources and suggests instance types that better match workload requirements, directly addressing the oversized EC2 instances in the test environment.

Answer

AWS DataSync

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AWS Shield

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AWS Artifact

Question 3

A company runs its customer-facing web app on EC2 behind an Application Load Balancer. The database is Amazon RDS for PostgreSQL. The requirement is that if a single Availability Zone fails, the database must automatically fail over within the same AWS Region with minimal application changes. Which database setup best meets this requirement?

Accepted Answer

Deploy the RDS PostgreSQL instance as Multi-AZ with automatic failover enabled.. Option B is correct because RDS Multi-AZ with automatic failover provides synchronous replication to a standby instance in a different Availability Zone. If the primary AZ fails, RDS automatically flips the DNS CNAME to the standby, resulting in minimal application changes (only a brief connection interruption). This meets the requirement for automatic failover within the same region without manual intervention.

Answer

Use an RDS single-AZ instance and periodically restore from automated backups if needed.

Answer

Create a read replica in a different AZ and use it only when the primary fails.

Answer

Use RDS with Multi-AZ disabled, but increase storage IOPS to prevent failover.

Question 4

A web application runs on an EC2 Auto Scaling group (ASG) behind an Application Load Balancer (ALB). The ASG spans three Availability Zones. After a deployment, new instances frequently fail the ALB target group health checks with HTTP 5xx responses and are quickly terminated by the ASG. What change most improves resiliency during deployments with minimal downtime by preventing premature removal of instances that are still starting?

Accepted Answer

Use a longer ASG health check grace period and deploy new instances using controlled replacement (for example, rolling instance refresh) so existing healthy instances continue serving while new ones warm up.. Option B is correct because increasing the ASG health check grace period gives new instances more time to complete their startup and pass the ALB health checks before the ASG marks them unhealthy. A rolling instance refresh replaces instances in a controlled manner, ensuring that existing healthy instances continue serving traffic while new instances warm up, minimizing downtime and preventing premature termination.

Answer

Reduce the ASG health check grace period to 0 seconds so issues are detected faster.

Answer

Restrict the ASG to a single Availability Zone so health check evaluation is simpler.

Answer

Disable ALB health checks so the ASG does not terminate instances on HTTP 5xx responses.

Question 5

A telemetry pipeline 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?

Accepted Answer

AWS Global Accelerator. AWS Global Accelerator uses the Anycast IP address concept to route traffic through the AWS global network to the optimal endpoint, reducing latency and jitter for global users. It does not cache content, making it ideal for dynamic responses that cannot be cached, and it integrates directly with an Application Load Balancer in a single Region.

Answer

S3 Cross-Region Replication

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CloudFront only with long TTLs

Answer

AWS Backup cross-Region copy

Question 6

A inventory service exposes a static website from S3 and CloudFront. Users should still receive cached pages if the S3 origin has a short outage. Which feature helps most? The architecture review board prefers a managed AWS-native control.

Accepted Answer

CloudFront caching with appropriate TTLs. CloudFront caching with appropriate TTLs allows cached responses to be served to users even when the S3 origin is temporarily unavailable. By setting a minimum TTL (e.g., 0 seconds for fresh content, but a higher default or maximum TTL for stale content), CloudFront can continue delivering previously cached pages from edge locations during an S3 outage, ensuring high availability and resilience. This is a managed AWS-native feature that aligns with the architecture review board's preference.

Answer

AWS Backup Vault Lock

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IAM Access Analyzer

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S3 Select

Question 7

A ticket booking system stores uploaded documents in S3. The business requires a copy in another AWS Region for disaster recovery. What should be configured? The design must avoid adding custom operational scripts.

Accepted Answer

S3 Cross-Region Replication with versioning enabled. S3 Cross-Region Replication (CRR) automatically replicates objects from a source bucket in one AWS Region to a destination bucket in another Region, providing a disaster recovery copy without custom scripts. Enabling versioning on both buckets is a prerequisite for CRR, ensuring that all object versions are replicated and that the destination bucket can maintain a complete history of changes.

Answer

S3 lifecycle transition to Glacier Flexible Retrieval

Answer

An EBS snapshot schedule

Answer

A CloudFront distribution

Question 8

A site serves static assets (JS/CSS) through CloudFront from an S3 origin. After a recent frontend change, CloudFront shows a cache hit ratio below 20%. In CloudFront access logs, requests to the same asset URL path differ by a query parameter named rnd (a random value appended by the app on every request). The origin content is identical regardless of rnd. What is the best CloudFront configuration change to restore effective caching?

Accepted Answer

Create a custom CloudFront Cache Policy that does not include the rnd query parameter in the cache key (whitelist only required parameters, or forward no query strings).. The rnd query parameter makes each request appear unique to CloudFront, causing a cache miss for every request even though the underlying content is identical. By creating a custom cache policy that either forwards no query strings or whitelists only required parameters, CloudFront will ignore the rnd parameter when computing the cache key, allowing it to serve cached responses and dramatically improve the cache hit ratio.

Answer

Increase the origin response Cache-Control max-age header on S3 so CloudFront caches longer even with different rnd values.

Answer

Disable compression on CloudFront so the response body is identical byte-for-byte and cache hits improve.

Answer

Switch the origin from S3 to an ALB so CloudFront can cache based on ALB target health checks instead of the query string.

Question 9

A video platform uses Amazon Aurora. The workload has many short-lived database connections from Lambda functions, causing connection storms. What should be added? The architecture review board prefers a managed AWS-native control.

Accepted Answer

RDS Proxy. RDS Proxy is the correct choice because it manages a pool of reusable database connections, allowing Lambda functions to share and reuse connections rather than opening and closing them with each invocation. This eliminates connection storms by buffering short-lived connections from Lambda and reducing the load on the Aurora database, all as a fully managed AWS-native service.

Answer

S3 Select

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An internet gateway

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A larger Route 53 hosted zone

Question 10

A web API runs on an Auto Scaling group (ASG) behind an Application Load Balancer (ALB). During traffic spikes, users experience request timeouts even though CPU stays below 40%. After investigation, you find the ASG often has too few healthy targets to handle the current request rate. Which change will best improve responsiveness during spikes?

Accepted Answer

Create a target tracking scaling policy using an ALB metric such as RequestCountPerTarget or TargetResponseTime.. Option B is correct because the issue is that the ASG has too few healthy targets to handle the request rate, even though CPU is low. A target tracking scaling policy based on RequestCountPerTarget or TargetResponseTime directly aligns scaling with the ALB's view of demand, ensuring the ASG adds instances when request rates spike, regardless of CPU utilization. This addresses the root cause—insufficient capacity to serve incoming requests—rather than relying on a metric (CPU) that does not reflect the bottleneck.

Answer

Keep the ASG scaling policy based on CPU utilization, but increase the ASG min capacity by 50%.

Answer

Enable EC2 detailed monitoring for one-minute granularity and keep CPU scaling.

Answer

Switch to scaling based on the ASG network out bytes metric only, ignoring ALB response metrics.