A yarrow-field trial must flip the useNewSampler flag without redeploying the App Service. Where should that feature flag live?
Select an answer to reveal the explanation.
Short Explanation
Feature flags are App Configuration’s job—flip useNewSampler in the store and let the app notice without a redeploy. Key Vault is for secrets, not Boolean toggles named True.
Full Explanation
Feature flags are a first-class App Configuration capability. The yarrow-field trial should store useNewSampler as a feature flag (or a clearly named non-secret key) in Azure App Configuration and enable dynamic refresh so App Service instances pick up the flip without a redeploy. That keeps the municipal trial's sampler switch in the operations plane rather than in a release pipeline.
Storing the flag as a Key Vault secret whose value is the literal string True fails the separation of concerns: Key Vault is for credentials and cryptographic material, not Boolean product toggles, and secret reads are the wrong API surface for frequent flag evaluation. Rewriting an Application Insights availability-test header each hour fails because availability tests probe endpoints; they are not a configuration distribution channel for application logic. Treating a Redis cache key as the flag home because toggles sound like caching fails the AZ-204 skill map—Redis may cache computed results elsewhere, but feature management for this exam centers on App Configuration, not inventing a toggle protocol in a cache.
Exam caveat: combine the flag with labels or targeting filters when test versus production must diverge; a single unlabelled Boolean can still bleed across environments if every host reads the same key. Operational check: flip useNewSampler in the App Configuration portal (or CLI), wait for the configured refresh interval or sentinel change, and verify running instances switch sampler behavior without an App Service restart.