I've seen a lot of talk about cold starts being a major issue with Azure Functions, especially when using the consumption tier. However, I also heard that you can set up warm-up functions that ping your API regularly to avoid these cold starts, which essentially prevents deallocation. Does this truly fix the cold start problem?
I'm considering migrating my small .NET API to Azure Functions since I have only a few controllers, but paying $60 a month for a basic App Service plan is not feasible for me right now. If I set up pings every five minutes, that's about 43,200 executions monthly, which seems manageable given the free tier and pay-as-you-go options. I already have servers available or could create a timer function for this. Just to clarify, I'm not interested in using container apps.
5 Answers
Have you thought about a low-cost compute VM? They start around $15. Just a thought if you're looking for something production-ready while keeping it cheap.
From what I've seen, cold starts can still be a hassle for HTTP-triggered Azure Functions, especially if users are waiting for a response. It works better for background tasks or message processing. By the way, instead of the $60 plan, you could consider a B1 Linux plan for just $13 a month. That could host several small applications without breaking the bank.
I agree, cold starts are pretty rough, especially with HTTP calls. But if you use the flex consumption plan, it might reduce the issues! I'm curious how it's been for others.
The low-load plan you’re considering is definitely the cheapest option, but if you want reliability, you might have to upgrade to an App Service Plan. Always On is really helpful, but those timer-trigger functions might not be totally reliable either!
Using a flex consumption plan with an always-on instance could solve your issues, but keep in mind their free grant is less than with the standard consumption. Still, if you set up timer functions for warm-ups, that could keep you within budget while providing the required responsiveness!
Yeah, I considered that, but if those warmup functions actually work for you, the consumption tier might be the way to go!
Honestly, if you need consistent availability for your endpoints, you’re better off with an App Service or Container App that uses provisioned compute. Functions aren't designed as a full API replacement, especially with controllers. Why not container apps? They can be cheaper, around $10 a month!
That’s true, using Azure Functions in the App Service with always-on features can give you some extra reliability. I agree with your point about the cost-effectiveness of container apps for simple web APIs!
I've tried running APIs on basic instances; they're super limited. The moment traffic picks up, the CPU credits drain, and that's not ideal!