Problems with scoped lifetime services (AddScoped)

[heikkilamarko]

Hi,

We are using durable functions with dependency injection. In our Startup.cs file, we register our dependencies as follows:

services.AddScoped<IMyService>(serviceProvider => new MyService(...))

In our activity function, we are using normal constructor injection to get IMyService instances.

The problem is that even if we are using AddScoped for registering the service, during the activity function run, each class that asks for the service, gets a different instance of IMyService. This breaks our app logic, because IMyService users won't see each other's changes.

As a workaround to the earlier Azure Functions runtime DI issues, we had the following pinning in place FUNCTIONS_EXTENSION_VERSION = 2.0.12673.0. The pinned version is not supported anymore by Azure, so our function DI is now broken again.

[heikkilamarko]

I find it hard to believe this is by design. If it is so, documentation should state that very clearly.

[heikkilamarko]

The problem is not durable function specific. Same happens with normal TimerTrigger functions also.

[heikkilamarko]

I made more experiments and it seem that the DI problem occurs only when I have used services.AddHttpClient() to register HttpClients. If I comment out services.AddHttpClient() calls, AddScoped works as expected.

[dhanapalschandran]

Hi @heikkilamarko I am also facing the same issue, when this issue happens last week I have pinned to older runtime version, then it started working, now again breaking. I agree it's not an issue with durable function. Even I am using the same DI pattern for HttpClients, Do we have any workaround for httpclient register or waiting for team to provide global fix

[unt1tled]

@dhanapalschandran Same thing on my side. Could it be breaking again due to #5096?

[fabiocav]

@heikkilamarko can you please share repro code? Is this happening with factory registrations only? Some more details/repro will ensure we're looking exactly at the issue you're running into.

@unt1tled / @dhanapalschandran if you can share the code you're having issues with, we can validate with your scenarios as well.

Thanks!

[heikkilamarko]

Hi. See below for a repro code (see the comment block in the function code):

using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Azure.WebJobs;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using System.Net.Http;

[assembly: FunctionsStartup(typeof(Demo.App.Startup))]

namespace Demo.App
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            var services = builder.Services;

            services.AddHttpClient<MyHttpClient>();

            services
                .AddScoped<IMyService, MyService>()
                .AddScoped<IMyServiceSetter, MyServiceSetter>()
                .AddScoped<IMyServiceGetter, MyServiceGetter>();
        }
    }

    public class MyHttpClient
    {
        private readonly HttpClient httpClient;

        public MyHttpClient(HttpClient httpClient)
        {
            this.httpClient = httpClient;
        }
    }

    public interface IMyService
    {
        void Set(int value);

        int Get();
    }

    public class MyService : IMyService
    {
        private int value = 0;

        public int Get()
        {
            return value;
        }

        public void Set(int value)
        {
            this.value = value;
        }
    }

    public interface IMyServiceSetter
    {
        void SetValue(int value);
    }

    public class MyServiceSetter : IMyServiceSetter
    {
        private readonly IMyService myService;
        private readonly IMyServiceGetter myServiceGetter;

        public MyServiceSetter(IMyService myService, IMyServiceGetter myServiceGetter)
        {
            this.myService = myService;
            this.myServiceGetter = myServiceGetter;
        }

        public void SetValue(int value)
        {
            myService.Set(value);
        }
    }

    public interface IMyServiceGetter
    {
        int GetValue();
    }

    public class MyServiceGetter : IMyServiceGetter
    {
        private readonly IMyService myService;
        private readonly MyHttpClient myHttpClient;

        public MyServiceGetter(IMyService myService, MyHttpClient myHttpClient)
        {
            this.myService = myService;
            this.myHttpClient = myHttpClient;
        }

        public int GetValue()
        {
            return myService.Get();
        }
    }

    public class DemoFunction
    {
        private readonly IMyServiceSetter myServiceSetter;
        private readonly IMyServiceGetter myServiceGetter;

        public DemoFunction(
            IMyServiceSetter myServiceSetter,
            IMyServiceGetter myServiceGetter)
        {
            this.myServiceSetter = myServiceSetter;
            this.myServiceGetter = myServiceGetter;
        }

        [FunctionName("Demo")]
        public void Demo([TimerTrigger("0 */5 * * * *", RunOnStartup = true)]TimerInfo timerInfo, ILogger log)
        {
            int value1 = 123;
            myServiceSetter.SetValue(value1);
            int value2 = myServiceGetter.GetValue();

            // Logs '123 - 0'
            // It means that MyServiceGetter and MyServiceSetter got different IMyservice instances.
            // Should be the same since we are using AddScoped to register services.
            // ---
            // If you comment out MyHttpClient injection from MyServiceGetter, it logs '123 - 123'.
            log.LogInformation($"{value1} - {value2}");
        }
    }
}

[t-l-k]

I believe this is the same as my issue #4914 - clearly something wrong with scoped registrations.

@fabiocav can we get an update on these tickets? Are they being investigated? Thx