AZ-400 Question 172
Select 2You are developing a .NET microservice named MyService that uses Azure App Configuration Feature Manager to store and manage feature flags. Your goal is to dynamically refresh these feature flags in your microservice so that any updates made in Azure App Configuration are picked up without requiring a redeployment. Which two actions should you take? (Choose two.)
- A
Enable the refresh middleware and configure dynamic refresh in your microservice using the Azure App Configuration NuGet packages.
- B
Store feature flags as environment variables in your Azure DevOps pipeline and redeploy every time a flag changes.
- C
Configure a sentinel key in Azure App Configuration that triggers a refresh event when updated.
- D
Hard-code all feature flags directly in appsettings.json so the application does not rely on Azure App Configuration during runtime.
Show answer and explanation
Correct answers: A, C
Explanation
To implement dynamic feature flags with Azure App Configuration Feature Manager in a .NET application, you typically add the Azure App Configuration NuGet package, enable refresh functionality, and configure a sentinel key. When the sentinel key changes, the microservice knows to refresh its settings and load updated flags. For more details, refer to Microsoft� best practices at: https://learn.microsoft.com/azure/azure-app-configuration/howto-integrate-azure-managed-service-identity?tabs=core5#refresh-dynamic-configuration.
- A. Correct.
Correct. Enabling refresh middleware (e.g., using AzureAppConfigurationRefresh) and configuring dynamic refresh is essential to allow an application to periodically check for updates to feature flags at runtime.
- B. Incorrect.
Incorrect. Storing flags exclusively as environment variables in the pipeline and redeploying is not the recommended way to handle dynamic feature flag updates. This approach requires a full redeployment for each change rather than leveraging an on-the-fly refresh.
- C. Correct.
Correct. A sentinel key (or a configuration event trigger) in Azure App Configuration helps the application understand when a refresh is needed, avoiding the need for manual action or redeployment.
- D. Incorrect.
Incorrect. Hard-coding flags in appsettings.json makes the application rely on static configuration. You would need to update and redeploy the service for each change, which defeats the purpose of using Azure App Configuration for dynamic feature control.