Microsoft Azure Documentation

Frequently Asked Questions (FAQ)

• What is a "cold start" in Azure Functions and how can I mitigate it?
  A cold start occurs when your function app hasn't been active for a while and needs to be initialized before processing a request. This can introduce latency. Mitigation strategies include:

  • Using "Always On" setting (for Consumption plan, this is a paid feature, but for Premium/Dedicated plans it's standard).
  • Implementing pre-warming triggers.
  • Optimizing function code for faster initialization.
  • Choosing a suitable hosting plan (Premium plans offer lower latency).
• How do I handle errors and exceptions gracefully in Azure Functions?
  You can handle errors using standard try-catch blocks in your function code. For more advanced error management and logging, integrate with Application Insights. Ensure you return appropriate HTTP status codes for web-triggered functions. You can also configure retry policies for durable functions.
• What are the best practices for logging in Azure Functions?
  Use the built-in logging features provided by the Azure Functions SDK. For structured logging, consider using a structured logging library. Integrate with Application Insights for centralized logging, powerful querying, and alerting capabilities. Log key events, errors, and performance metrics.

  # Example in Python import logging def main(req: func.HttpRequest) -> func.HttpResponse: logging.info('Python HTTP trigger function processed a request.') try: name = req.params.get('name') if not name: try: req_body = req.get_json() except ValueError: pass else: name = req_body.get('name') logging.warning("Name parameter not provided. Attempting to get from body.") if name: logging.info(f"Processing request for name: {name}") return func.HttpResponse(f"Hello, {name}. This HTTP triggered function executed successfully.") else: logging.error("No name provided in request.") return func.HttpResponse("Please pass a name in the query string or in the request body", status_code=400) except Exception as e: logging.exception(f"An unexpected error occurred: {e}") return func.HttpResponse("An internal server error occurred.", status_code=500)
• How can I monitor the performance of my Azure Functions?
  Azure Monitor and Application Insights are your primary tools. You can track execution times, request rates, error counts, and resource utilization. Set up alerts based on performance metrics to proactively identify issues. Analyze dependency calls to understand performance bottlenecks.