SAA-C03 Design High-Performing Architectures Practice Question

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?

⚠ Common exam trap

The trap here is assuming that a single S3 bucket can only serve a fixed amount of read throughput regardless of how requests are distributed across key prefixes.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

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 analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Enable S3 Cross-Region Replication to a second bucket and have half the instances read from the replica.
Why it's wrong here
Cross-Region Replication copies objects asynchronously to another Region and incurs inter-Region data transfer and replication costs. It does not increase read throughput for the source bucket, and splitting reads across Regions adds latency and complexity. The scenario explicitly wants to minimize request costs, so replication is not appropriate here.
✗
Use S3 Transfer Acceleration on the source bucket and have the EC2 instances read through the accelerated endpoint.
Why it's wrong here
S3 Transfer Acceleration speeds up uploads and downloads over long geographic distances by routing traffic through AWS edge locations, but it does not raise the per-prefix request rate limit for EC2 instances in the same Region. It also adds a separate acceleration fee, which conflicts with the goal of minimizing request costs. For in-Region batch reads, it provides little to no throughput gain.
✗
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.
Why it's wrong here
S3 File Gateway is designed to provide on-premises or hybrid access to S3 through NFS or SMB, caching frequently accessed data locally. It adds a gateway appliance and network hop, and it does not increase the underlying S3 request rate for a large parallel batch read. For EC2 instances already in the Region, direct S3 API calls are more efficient and cheaper.
✓
Have the EC2 instances issue ranged GET requests against many distinct prefixes in parallel to spread the load across S3 partitions.
Why this is correct
S3 automatically partitions a bucket by key prefix, and each partition supports a limited request rate. By issuing ranged GETs and spreading reads across many prefixes, the fleet drives parallel requests to multiple partitions, raising aggregate throughput. This is the standard approach for maximizing read performance from EC2 in the same Region without changing storage class or paying for acceleration.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

SAA-C03 Design High-Performing Architectures Practice Question

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

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