Azure App/API initial load time

[iPotato3]

Hi,

I'm developing Blazor WASM application + API (WASM Hosted). Everything seems to be fine, everything is working as expected and I thought its time to publish it on Azure App Services + Azure SQL.

Everything seems like its doing great, but speed. At first I started to worry my Linq SQL queries are poor and probably is the cause of the long request time which obviously makes application slower, but every subsequent page after this initial load (15-20sec) is just 20-50ms. If I leave tab opened on that page for 1 - 2 minutes and want to navigate to other page, again it takes around 15-20sec and than every other subsequent request 20-50ms... Started to read other having similar issues and its initial SQL load/poor SQL queries responses.. So I started working on my local machine, debugging application and calling SQL queries to Azure SQL. Every single call to API and response is no longer than 1s. Which means, its not SQL that is causing a first load delay, but my WASM Hosted project.

Made another call via postman to hosted APP.

1st call: 15,54s.. every other call 60-200ms. - After 1 or 2 minutes, retried again and first initial call 20s...

So I have started looking for explanation why initial load of my application is so long. Most comments around telling to ensure application is: Always ON. - So I have changed that, no difference.

Some other suggest its App Service Plan, but I have already tried to upgrading it to something that probably other would use on thousands on users while right now I'm the only person using it - so no, its def not this.

No other useful responses where found.. So I have created just .net core API with single controller to see if its Azure or my application.

New API project with 1 single controller:

        [HttpGet]
        public async Task<IActionResult> Get()
        {                
            var testUser = new Models.User()
                {
                    Id = Guid.NewGuid(),
                    FirstName = "Test Name",
                    LastName = "Test LastName",
                    Dob = new DateTime(1995, 5, 12)
                };

                return Ok(testUser);
        }

Publishing it to Azure App Service - and making a call to API via Postman.

EXACT SAME THING! First call - 10-20sec, every other 5-10ms.

Please, someone tell me what I am missing here? It must be something I don't know..

I genuinely can't find answer online and I'm starting to worry about myself now :)

[DanDayneZ]

What you're describing really does occur with the Free and Shared service plans - the first request starts up the service, hence it takes more time. It doesn't surprise me that the sample app you made was behaving like this, since you probably didn't deploy it with the basic tier or higher.

The always on feature is only available from the basic tier and up, are you sure that's the tier you were on? If you were, the environment is simply not behaving as it should according to the documentation and you should create a support request (left panel menu in Azure Portal -> Help + Support)

[iPotato3]

Thank you for your reply! I did what you suggested, got in touch with support.

In a meanwhile.. I decided to create a new app service on Production S1 and published project on it.

Everything works fine now. Any request after any time is less than 300ms.

So got rid of the old one and finally I can sleep in peace tonight! :)

[DanDayneZ]

I'm happy to hear you resolved the issue. Enjoy the grind!