BenchMark Quizzes by MDFT Pro

Fix Unreliable Timer-Triggered Azure Function

You work as a Scheduled Automation Developer for MDFT Pro, a well-known training agency that delivers certification courses to students worldwide. Mark, the Operations Automation Lead, has deployed an Azure Function App running on an App Service Plan to perform nightly batch operations. The function uses a Timer trigger configured with a CRON expression to run at 2:00 AM every night, generating completion certificates for students who finished courses that day, sending reminder emails about upcoming exam dates, and archiving old course materials. However, trainers report that certificates are sometimes missing, and the operations logs show the timer trigger is not firing reliably—sometimes it runs on schedule, other times it’s delayed or skipped entirely. Students complain about delayed certificates and inconsistent reminder emails. The function must execute reliably every night to ensure students receive their certificates promptly and exam reminders are sent on time.

Which two actions should you perform to improve the timer trigger reliability?

Choose all correct answers from the options below.

Explanations for each answer:

Verify that Always On is enabled is correct. When running timer-triggered functions on an App Service Plan without Always On enabled, the app can go idle after periods of inactivity, preventing timer triggers from firing reliably. Enabling Always On keeps the function app loaded and ensures timer triggers execute on schedule, especially important for scheduled batch processes and maintenance tasks.
Ensure that the function has a retry configured is correct. Adding retry logic helps handle transient failures that might cause a timer trigger to miss its scheduled execution. If a timer trigger fails due to temporary issues (like resource contention or brief network problems), retry configuration ensures the function attempts execution again, improving reliability for critical scheduled operations.
Modify the trigger to use Consumption mode instead of the App Service plan is incorrect. Consumption mode doesn't solve timer reliability issues—in fact, it can introduce cold start delays that make timer triggers less precise. The Consumption plan is designed for event-driven workloads, while App Service plans with Always On are better suited for reliable scheduled executions via timer triggers.
Modify the trigger to use a SignalR trigger is incorrect. SignalR triggers are designed for real-time bidirectional communication scenarios, not scheduled batch processing. Changing from a timer trigger to a SignalR trigger completely changes the execution model and wouldn't provide the scheduled, periodic execution needed for batch operations like certificate generation.

Learn more about App Service Plan Functions:

Dedicated Plan Configuration

Practice Exam

Fix Unreliable Timer-Triggered Azure Function

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