I already read Understanding Serverless Cold Start | Azure App Service Team Blog article. One the the comments said You can avoid cold start in consumption plan also by calling function from Azure Logic app in every 4 mins interval.
I was trying to make 1 request per 4 minutes to one function of my app but this doesn’t always works. It sometimes still cold start. I know it's a hack. Is there any better way to ensure App always running when using Consumption plan?
I tried to answer this question in my article Cold Starts Beyond First Request in Azure Functions.
In short, there doesn't seem to be a way to avoid cold starts completely. Keep alive calls will make the life span of a given instance longer, but it won't make it indefinitely long.
For now, Cold Starts seem to be a genuine issues of FaaS implementations, they get optimized over time, but probably you won't be able to reduce them to 0.
According to this article, we could use Event Grid trigger to avoid cold-start delay.
Note
When you're using a blob trigger on a Consumption plan, there can be up to a 10-minute delay in processing new blobs if a function app has gone idle. After the function app is running, blobs are processed immediately. To avoid this cold-start delay, use an App Service plan with Always On enabled, or use the Event Grid trigger.
For more details to avoid cold-start delay, refer to the two articles, 1 and 2.
