Guidance on Benchmark Response Time for Azure Function App

Himanshu Bhardwaj (Wipro Limited) 0 Reputation points
2025-12-11T06:33:29.7+00:00

Hi Team,
I am currently working on benchmarking and scaling configurations for an Azure Function App and would like to understand Microsoft’s recommendations regarding response time.

We have a set of mock functions using a combination of GET and POST requests with the following payloads:

  • GET response sizes: 10 KB, 100 KB, 300 KB
  • POST request payloads: 10 KB, 100 KB, 300 KB

I understand that response times can vary based on factors such as function implementation, business logic, and hosting configuration. For reference, we are testing the Function App using a Premium Service Plan (P1V3).

Currently, what we are observing is:

  • When we increase concurrent users, latency becomes significantly higher.
  • When we keep concurrency lower, the average response time in Azure Load Testing is under 500 ms.

However, I am not sure what should be considered an acceptable response time benchmark so that I can properly adjust concurrency levels.

Could you please advise:

  1. What would be considered an ideal response time for these mock functions?
  2. What should be the expected response time when working with real-time data?
  3. Are there any official guidelines or best practices for determining acceptable response time and concurrency thresholds?

Your guidance will help us set accurate benchmarks and optimize performance.I am currently working on benchmarking and scaling configurations for an Azure Function App and would like to understand Microsoft’s recommendations regarding response time.

We have a set of mock functions using a combination of GET and POST requests with the following payloads:

  • GET response sizes: 10 KB, 100 KB, 300 KB
  • POST request payloads: 10 KB, 100 KB, 300 KB

I understand that response times can vary based on factors such as function implementation, business logic, and hosting configuration. For reference, we are testing the Function App using a Premium Service Plan (P1V3).

Currently, what we are observing is:

  • When we increase concurrent users, latency becomes significantly higher.
  • When we keep concurrency lower, the average response time in Azure Load Testing is under 500 ms.

However, I am not sure what should be considered an acceptable response time benchmark so that I can properly adjust concurrency levels.

Could you please advise:

  1. What would be considered an ideal response time for these mock functions?
  2. What should be the expected response time when working with real-time data?
  3. Are there any official guidelines or best practices for determining acceptable response time and concurrency thresholds?

Your guidance will help us set accurate benchmarks and optimize performance.

Regards
Himanshu

Azure Functions
Azure Functions
An Azure service that provides an event-driven serverless compute platform.
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  1. Q&A Assist
    2025-12-11T06:33:44.4433333+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    When benchmarking response times for Azure Function Apps, particularly under a Premium Service Plan (P1V3), several factors influence what can be considered ideal or acceptable response times. Here are some guidelines based on best practices:

    1. Ideal Response Time: While specific benchmarks can vary, a general target for response times is to aim for under 200 ms for most functions. However, achieving this can depend on the complexity of the function and the payload size. For your mock functions with payloads of 10 KB, 100 KB, and 300 KB, maintaining an average response time under 500 ms, as you've observed, is a good starting point, especially under lower concurrency.
    2. Expected Response Time for Real-Time Data: For functions processing real-time data, the response time should ideally be as low as possible, ideally under 200 ms. However, this can be challenging depending on the data processing involved. It's crucial to optimize the function code and manage dependencies effectively to minimize latency.
    3. Official Guidelines and Best Practices: Microsoft recommends the following best practices to optimize performance and manage acceptable response times:
      • Optimize Function Code: Ensure that your code is efficient and minimizes resource consumption. Avoid long-running operations.
      • Enable Autoscaling: Leverage the autoscaling capabilities of Azure Functions to handle varying loads effectively.
      • Monitor Performance Metrics: Use Application Insights to track key performance metrics and set alerts for performance degradation.
      • Optimize Cold Starts: Use prewarmed instances in the Elastic Premium plan to reduce latency associated with cold starts.
      • Test Under Load: Perform stress testing to understand how your functions behave under high concurrency and adjust your configurations accordingly.

    These guidelines will help you set accurate benchmarks and optimize the performance of your Azure Function App.


    References:

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  2. Anurag Rohikar 3,185 Reputation points Microsoft External Staff Moderator
    2025-12-11T06:41:31.92+00:00

    Hey Himanshu Bhardwaj (Wipro Limited)! It sounds like you're digging deep into benchmarking and scaling configurations for your Azure Function App, which is great! Here’s what I can share based on your questions:

    1. Ideal Response Time for Mock Functions: While an exact benchmark can vary significantly depending on numerous factors, a response time under 500 ms for your mock functions is generally a good target when concurrency is kept low. For functions in a Production or high-concurrency scenario, you may aim for a response time below 300 ms as a more ambitious benchmark.
    2. Expected Response Time with Real-Time Data: When working with real-time data, response times can be more unpredictable, as it depends on the complexity of the business logic, downstream service response times, and network conditions. Typically, you should strive to keep average response times similar to your mock functions (<500 ms), but anticipate potential spikes beyond this during peak loads.
    3. Official Guidelines and Best Practices:
      • Concurrency: Microsoft recommends understanding your function's throttling limits and configuring your hosting plan effectively (Premium services being less prone to cold-start issues).
      • Performance Optimization:
        • Monitor CPU and memory usage to identify bottlenecks.
        • Utilize Application Insights for tracking performance and response times.
        • Consider implementing warm-up triggers or using Always-Ready instances in your Premium plan to reduce cold starts.
      • Scaling Guidance: For the Premium plan, consider reviewing the maximum burst limits and setting up scaling appropriately to match your workload.

    Additional Resources:

    I hope this information helps you set accurate benchmarks and optimize the performance of your Azure Function App. If you have more specific metrics to share, feel free to let me know, and I can help refine this further!

    Note: This content was drafted with the help of an AI system.

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