Comparing Azure Functions Hosting Plans

The other day I sit down to renew my AZ-204, and one of the questions called my attention. I don't remember the exact question, but it was related to Azure Functions hosting plans. One of the options was "Flex Consumption Plan" ... Well, I had no idea what was that, and I knew the answer was another, but that got my attention. 🤔

Since I took 5 min to read a bit about them, here is a quick break down of these options. Go grab a drink, and let’s get into it!

Azure Functions?

Before we jump into the hosting plans, let’s quickly recap whats up with Azure Functions:

• Serverless Architecture: You focus on writing code without worrying about the underlying infrastructure.
• Scalability: Automatically scales based on demand—no manual server management!
• Cost-Effective: Pay only for "what you use", which is perfect for startups and small projects.

The Hosting Plans Breakdown

Azure Functions offers five hosting plans now: Consumption Plan, Premium Plan, Dedicated (App Service) Plan, Container Apps , and the new Flex Consumption Plan.

1. Consumption Plan

Best For: Small projects, prototypes, or applications with variable workloads.

• Pricing: You pay per execution, which means if your function isn’t running, you’re not paying.
• Scaling: Automatically scales out to handle incoming requests.
• Limitations:
  • Maximum execution time of 5 minutes (can be extended to 10 min through configuring).
  • Cold starts can be a bummer if your function hasn’t been triggered in a while - I never really had that other than 3 to 5 sec.

2. Premium Plan

Best For: Applications needing more power and features, like VNET integration.

• Pricing: Fixed monthly fee plus execution costs.
• Scaling: Can scale to zero, but also allows for pre-warmed instances to reduce cold start times.
• Features:
  • Supports longer execution times (up to 60 minutes - now why would you?).
  • VNET integration for secure connections.
  • More powerful infrastructure options.

3. Dedicated (App Service) Plan

Best For: Enterprise applications or those requiring full control over the environment. A long time ago, the company I worked for would only use these. Quite a bunch of money, but predictable.

• Pricing: Fixed monthly fee based on the App Service plan tier.
• Scaling: Manual scaling; you control the number of instances.
• Features:
  • Full control over the hosting environment.
  • No cold starts since your functions are always warm.
  • Ideal for applications with consistent workloads. We were mostly using those for our durable functions.

4. Container Apps Plan

Best For: deploy of containerized function apps in a fully managed environment.

• Pricing: Pay-as-you-go based on resource usage.
• Scaling: Automatically scales based on demand, running alongside other microservices and APIs.
• Features:
  • Package custom libraries with your function code and app.
  • Migrate code execution from on-premises or legacy apps to cloud-native microservices in containers.
  • Avoid the overhead of managing Kubernetes clusters and dedicated compute.
  • Access high-end processing power with dedicated CPU compute resources for your functions.

5. Flex Consumption Plan

The new-comer (at least for me).

Best For: high scalability with more control over compute choices.

• Pricing: Pay-as-you-go billing model, with options for always-ready instances.
• Scaling: Instances are dynamically added and removed based on incoming events and configured concurrency.
• Features:
  • Always-Ready Instances: You can specify a number of instances that are always ready to handle requests, reducing cold start times.
  • Virtual Network Integration: Connect your apps to other Azure services securely.
  • Memory Size Selection: Choose between 2 and 4 GB instance memory sizes based on your app's needs.
  • Fast Scaling: Scales automatically based on demand, making it perfect for both HTTP and non-HTTP applications.

Key Takeaways

• Consumption Plan is great for lightweight, sporadic workloads.
• Premium Plan strikes a balance between cost and performance, perfect for growing applications.
• Dedicated Plan is for those who need full control and reliability.
• Container Apps plan is perfect for containerized functions without the hassle of K8s.
• Flex Consumption Plan offers a great alternative to both Consumption and Premium: serverless benefits with added flexibility and scalability.

What’s New?

I don't know how recent are this updates, but I find it nice to have yet another option for the Functions: Flex Consumption Plan. Like I mentioned, this is also relevant for those of you prepping for the AZ-204 exam. 😉!

Here's a copy of the comparison from Microsoft Docs:

Conclusion

I myself used only 3 of those plans so far. Have you tried the Flexible or Container already? Share your experiences in the comments below! I'd also appreciate if you'd let me know if I should try and learn something else to write here as well 😃

Surely choosing the right Azure Functions hosting plan can make a significant difference in your project’s performance - and cost.

And if you’re gearing up for the AZ-204 exam, don’t forget to check out the official resources to stay updated on the latest changes.

Here's the docs: https://learn.microsoft.com/en-us/azure/azure-functions/functions-scale

Thanks for reading and happy clouding! 🚀