How to access AWS AppConfig data in Lambda with least effort?

DVA-C02 By islever Editorial Last updated

Short answer

B Configure the AWS AppConfig Agent Lambda extension. Access the dynamic configuration data by calling the extension on a local host.

Question

A developer built an application by using multiple AWS Lambda functions. The Lambda functions must access dynamic configuration data at runtime. The data is maintained as a 6 KB JSON document in AWS AppConfig. The configuration data needs to be updated without requiring the redeployment of the application. The developer needs a solution that will give the Lambda functions access to the dynamic configuration data. What should the developer do to meet these requirements with the LEAST development effort?
  1. Migrate the document from AWS AppConfig to a Lambda environment variable. Read the document at the runtime.
  2. Configure the AWS AppConfig Agent Lambda extension. Access the dynamic configuration data by calling the extension on a local host. Correct Answer
  3. Use the AWS X-Ray SDK to call the AWS AppConfig APIs. Retrieve the configuration file at runtime.
  4. Migrate the configuration file to a Lambda deployment package. Read the file from the file system at runtime.

Key Takeaways

The question tests knowledge of Lambda extensions versus manual API calls or environment variables, with the trap being the 4 KB size limit on environment variables.

To access dynamic configuration in AWS Lambda with minimal code, developers should use the AWS AppConfig Agent Lambda extension. This approach allows runtime updates without redeployment and handles the retrieval logic automatically.

Common mistake: Choosing environment variables (Option A) is a common mistake because the 6 KB configuration exceeds the Lambda environment variable limit of 4 KB.

Expert Analysis

Why the Answer Is Correct

The AWS AppConfig Agent Lambda extension is designed specifically to provide local access to configuration data via localhost. It runs as a sidecar process that fetches and caches the configuration, allowing the function to read it without writing custom API logic, thus minimizing development effort.

Why the Other Options Are Wrong

Option A is incorrect because Lambda environment variables are limited to 4 KB, which is insufficient for the 6 KB JSON document. Option C is incorrect because the AWS X-Ray SDK is used for tracing and debugging, not for retrieving configuration data; using the standard SDK would require more code than the extension. Option D is incorrect because including the file in the deployment package necessitates redeploying the function whenever the configuration changes.

Community Comment Notes

Community members confirmed that Option B is the intended solution for AppConfig integration with Lambda. One comment explicitly pointed out the 4 KB size limit of environment variables as the disqualifying factor for Option A.

Official Reference

https://docs.aws.amazon.com/appconfig/latest/userguide/appconfig-integration-lambda-extensions.html

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

Exam Strategy

Always verify Lambda environment variable size limits (4 KB) when configuration data is mentioned. For dynamic configuration updates without redeployment, prioritize Lambda extensions over direct API calls or packaging files.

Community Votes

B
100%

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

Discussion 4 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 4

  1. KennethNg923 👍 4 Answered B
    The AWS AppConfig Agent Lambda extension is specifically designed to provide easy access to AppConfig configurations from Lambda functions. It allows for dynamic updates without redeployment and requires minimal development effort.
  2. Anandesh 👍 2 Answered B
    https://docs.aws.amazon.com/appconfig/latest/userguide/appconfig-integration-lambda-extensions.html
  3. albert_kuo 👍 2 Answered B
    Environment variables have a size limit of 4 KB, which is insufficient for a 6 KB document.
  4. komorebi 👍 1 Answered B
    Ansswer is B

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