Serverless Docker Container with Temporary Storage

SAA-C03 By islever Editorial Last updated

Design secure workloads and applications.

Short answer

C Create an Amazon Elastic Container Service (Amazon ECS) cluster that uses the AWS Fargate launch type with an Amazon EFS volume.

Question

A solutions architect needs to design the architecture for an application that a vendor provides as a Docker container image. The container needs 50 GB of storage available for temporary files. The infrastructure must be serverless. Which solution meets these requirements with the LEAST operational overhead?
  1. Create an AWS Lambda function that uses the Docker container image with an Amazon S3 mounted volume that has more than 50 GB of space.
  2. Create an AWS Lambda function that uses the Docker container image with an Amazon Elastic Block Store (Amazon EBS) volume that has more than 50 GB of space.
  3. Create an Amazon Elastic Container Service (Amazon ECS) cluster that uses the AWS Fargate launch type. Create a task definition for the container image with an Amazon Elastic File System (Amazon EFS) volume. Create a service with that task definition. Correct Answer
  4. Create an Amazon Elastic Container Service (Amazon ECS) cluster that uses the Amazon EC2 launch type with an Amazon Elastic Block Store (Amazon EBS) volume that has more than 50 GB of space. Create a task definition for the container image. Create a service with that task definition.

Key Takeaways

The question tests the ability to identify serverless container options (Fargate) versus managed infrastructure (EC2), while correctly interpreting 'temporary' as ephemeral application data rather than persistent storage.

This page explains how to design a serverless architecture for Docker containers requiring temporary storage using Amazon ECS Fargate and EFS, addressing common misconceptions about Lambda limitations.

Common mistake: Many candidates choose AWS Lambda because it is the most prominent serverless option, but they overlook that Lambda has strict execution time limits (15 minutes) and storage constraints (10GB total, much less for /tmp), making it unsuitable for long-running container workloads or large temporary files.

Expert Analysis

Why the Answer Is Correct

Option C is the correct solution because Amazon ECS with the Fargate launch type provides a fully serverless compute engine for containers, eliminating the need to manage EC2 instances. While EFS is typically associated with durable file storage, in this context, it serves as a scalable network filesystem for the container's working directory. The key is that Fargate handles the orchestration serverlessly, and EFS can be attached to tasks to provide the required 50GB of storage space without managing underlying servers.

Why the Other Options Are Wrong

Option A is incorrect because AWS Lambda is designed for short-lived, event-driven functions, not long-running containerized applications. Lambda also has a maximum deployment package size and /tmp limit (initially 512MB, expandable to 10GB total disk) which may not reliably support 50GB of temporary file operations depending on usage patterns, and S3 mounting is not native in the same way. Option B is invalid because Lambda does not support mounting EBS volumes directly. Option D involves Amazon EC2, which requires managing the underlying servers, violating the 'serverless' requirement.

Community Comment Notes

Community consensus strongly favors Option C. Users like stephensimudemy note that Lambda is "NOT ideal for long-running containerized applications." Others clarify that "Lambda storage limit: 10GB" makes it risky for 50GB requirements. Zinabu incorrectly argues for B based on a misunderstanding of 'temporary,' but the majority correctly identifies that Fargate is the only viable serverless container service listed.

Official Reference

https://docs.aws.amazon.com/AmazonECS/latest/developerguide/AWS_Fargate.html

This link opens the official vendor documentation in a new tab.

Exam Strategy

When you see 'Serverless' and 'Docker/Container', immediately think AWS Fargate or Lambda. If the workload is long-running or requires significant storage/network filesystems, Fargate is the choice; if it's event-driven and short-lived, consider Lambda. Always check storage limits against requirements.

Frequently Asked Questions

Why not use AWS Lambda for the container?

Lambda is limited to 15-minute executions and has strict storage caps (max 10GB total). It is not suitable for long-running containerized applications or large temporary file processing.

Is EFS considered temporary storage?

EFS is a durable file system, but in this exam context, it acts as the persistent network storage layer for the container's working directory, satisfying the 50GB requirement without managing servers.

More SAA-C03 FAQ →

Community Votes

C
100%

100% of anonymous learners picked answer C. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 7 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 7

  1. stephensimudemy 👍 7 Answered C
    Options A and B involve AWS Lambda, which is suitable for event-driven, short-lived compute tasks, but it's NOT ideal for long-running containerized applications and managing large volumes of data.
  2. sandordini 👍 4 Answered C
    Lambda would need Runtime interface clients (RIC) to host a container workload. Also Lambda storage limit: 10GB Fargate is Serverless >> C
  3. DZRomero 👍 2 Answered C
    The combination of ECS with Fargate and EFS (option C) provides a serverless solution that can run Docker containers and meet the storage requirements, all while minimizing operational overhead. You don't need to manage any servers, and the storage will automatically scale as needed. This makes it the best fit for the given requirements.
  4. zinabu 👍 1 Answered B
    the key word here is {" serverless + temporary file''} A: it uses S3 for storage that is not a temporary file storage system C: that was good using ECS with farget for serverless part but is uses EFS file system still it is a durable file system not temporary D: Using EBS was good to use for temporary file system but it is mounted on EC2 which is not serverless. so that we are left with ''B'' which uses [ lambda(serverless) + EBS(temporary storage)]
  5. LeonSauveterre 👍 1 Answered C
    A - Technically, temporary file access in Lambda is limited to the /tmp directory with a 512 MB limit. B - AWS Lambda does not natively support mounting EBS volumes. C - Looks good to me. D - ECS with EC2 is not serverless. FYI - Serverless infrastructure: Solutions must not involve managing servers or underlying infrastructure. AWS Fargate and AWS Lambda are serverless options, while Amazon ECS with EC2 launch type involves managing EC2 instances.
Show 2 more comments
  1. Andy_09 👍 6
    Option C
  2. dragongoseki 👍 2 Answered C
    C is right answer.

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