SAA-C03 Q274 · Serverless

Question

A company uses an Amazon EC2 instance to run a script to poll for and process messages in an Amazon Simple Queue Service (Amazon SQS) queue. The company wants to reduce operational costs while maintaining its ability to process a growing number of messages that are added to the queue. What should a solutions architect recommend to meet these requirements?

Accepted Answer

**Option C: Migrate the script to an AWS Lambda function** satisfies both requirements:

1. **Reduce operational costs**: Lambda uses a pay-per-invocation pricing model — you only pay for the compute time consumed while processing messages. When the queue is empty, you pay nothing. With EC2, the instance runs 24/7 regardless of whether there are messages to process, incurring constant costs.

2. **Handle a growing number of messages**: Lambda has a **native integration with SQS** as an event source. When messages arrive in the SQS queue, Lambda automatically invokes your function. As message volume grows, Lambda **scales automatically** — it can run up to thousands of concurrent invocations without any manual intervention. There is no need to manage polling logic; AWS handles it for you.

📖 Explanation

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📘 Key Concepts

🏗️ Architecture

⚙️ Operations

💰 Cost

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