SAP-C02 Practice Question: Accelerate Workload Migration and Modernization

A company is migrating a monolithic Java application to AWS. The application uses a shared file system for storing user-uploaded documents. The company wants to refactor the application to use a microservices architecture with decoupled storage and compute. The application currently writes files to a local directory and serves them via a web server. Which AWS service should be used to store the documents to enable stateless compute and independent scaling?

⚠ Common exam trap

The trap here is assuming that a shared file system like Amazon EFS is the best choice because it mimics the on-premises file share, but it does not provide the decoupling and statelessness required for a microservices architecture.

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

✓

Amazon S3

Amazon S3 provides durable, scalable object storage that decouples storage from compute, enabling a stateless microservices architecture. Other options like EFS, EBS, and FSx are file or block storage solutions that require mounting and are not optimized for decoupled, independently scaling services. S3 also integrates with other AWS services for event-driven processing.

Answer analysis

Option-by-option breakdown

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

✓
Amazon S3
Why this is correct
Amazon S3 is a highly durable, scalable object storage service that decouples storage from compute. By storing documents in S3, the application can be stateless, enabling independent scaling of microservices. S3 also provides features like versioning, lifecycle policies, and event notifications that can trigger downstream processing, making it ideal for modernized applications.
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Amazon FSx for Windows File Server
Why it's wrong here
Amazon FSx for Windows File Server is a managed Windows file system that supports SMB protocol. It is designed for Windows-based applications that require shared file storage with Windows ACLs. For a Java application on Linux, FSx adds unnecessary complexity and cost, and it still requires mounting, which does not achieve the decoupled, stateless architecture desired.
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Amazon Elastic File System (Amazon EFS)
Why it's wrong here
Amazon EFS provides a shared file system, but it is not ideal for storing user-uploaded documents in a microservices architecture because it requires mounting the file system to each compute instance, which adds operational overhead and limits statelessness. EFS is better suited for lift-and-shift scenarios or when applications require POSIX-compliant shared storage, not for decoupled object storage.
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Amazon Elastic Block Store (Amazon EBS)
Why it's wrong here
Amazon EBS provides block-level storage volumes for use with EC2 instances. It is not a shared file system and cannot be concurrently attached to multiple instances in a scalable way. Using EBS would tie the application to specific instances, preventing stateless compute and independent scaling, and would require replicating data across instances manually.

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

SAP-C02 Practice Question: Accelerate Workload Migration and Modernization

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

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