ObjectDisposedException: Cannot access a disposed object. Object name: 'IServiceProvider'

[ikyslyi]

Trying to run multiple parallel requests to GetCustomers, even without any logic inside

public async Task<GetCustomersResponse> Handle(GetCustomers request, CancellationToken cancellationToken)
{
    await Task.Delay(300, cancellationToken);
    var customer = new CustomerReadDto { Id = Guid.NewGuid(), CustomerId = 1, City = "New York" };
    return new GetCustomersResponse(new ListResultModel<CustomerReadDto>(new List<CustomerReadDto>(){ customer }, 10, 1, 10));
}

and getting such exception:

[13:47:46 ERR] HTTP GET /api/v1/customers responded 500 in 908.3350 ms
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'IServiceProvider'.
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ThrowHelper.ThrowObjectDisposedException()
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at MediatR.ServiceFactoryExtensions.GetInstances[T](ServiceFactory factory)
at MediatR.Wrappers.RequestHandlerWrapperImpl2.Handle(IRequest1 request, ServiceFactory serviceFactory, CancellationToken cancellationToken)
at MediatR.Mediator.Send[TResponse](IRequest1 request, CancellationToken cancellationToken) at BuildingBlocks.Core.CQRS.Query.QueryProcessor.SendAsync[TResponse](IQuery1 query, CancellationToken cancellationToken) in C:\Users\xxx\Projects\etc\ecommerce-modular-monolith\src\BuildingBlocks\BuildingBlocks.Core\CQRS\Query\QueryProcessor.cs:line 16
at FoodDelivery.Modules.Customers.Customers.Features.GettingCustomers.GetCustomersEndpoint.HandleAsync(GetCustomersRequest request, CancellationToken cancellationToken) in C:\Users\xxx\Projects\etc\ecommerce-modular-monolith\src\Modules\Customers\FoodDelivery.Modules.Customers\Customers\Features\GettingCustomers\GetCustomersEndpoint.cs:line 40
at lambda_method548(Closure, Object)
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Logged|12_1(ControllerActionInvoker invoker)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Logged|17_1(ResourceInvoker invoker)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Logged|17_1(ResourceInvoker invoker)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.g__AwaitRequestTask|7_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Prometheus.GrpcRequestCountMiddleware.Invoke(HttpContext context)
at Prometheus.HttpMetrics.HttpRequestDurationMiddleware.Invoke(HttpContext context)
at Prometheus.HttpMetrics.HttpRequestCountMiddleware.Invoke(HttpContext context)
at Prometheus.HttpMetrics.HttpInProgressMiddleware.Invoke(HttpContext context)
at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
at Serilog.AspNetCore.RequestLoggingMiddleware.Invoke(HttpContext httpContext)

Code to reproduce the issue:

class Program
{
static async Task Main(string[] args)
{
// Endpoint URL
string urlGet = "http://localhost:5000/api/v1/customers?Page=1&PageSize=10";
// Number of parallel requests
int numberOfRequests = 100;
// List to hold tasks
List tasks = new List();
using (HttpClient client = new HttpClient())
{
for (int i = 0; i < numberOfRequests; i++)
{
tasks.Add(SendGetRequest(client, urlGet));
}
// Wait for all requests to complete
await Task.WhenAll(tasks);
}
Console.WriteLine("All requests completed.");
}
static async Task SendGetRequest(HttpClient client, string url)
{
try
{
HttpResponseMessage response = await client.GetAsync(url);
string responseString = await response.Content.ReadAsStringAsync();
Console.WriteLine($"Response: {response.StatusCode} - {responseString}");
}
catch (Exception ex) { Console.WriteLine($"Error: {ex.Message}"); }
}
}

[ikyslyi]

A possible reason is described here
The solution that helped me is described here

to me, the fastest way was to create a new Mediator instance in QueryProcessor/CommandProcessor directly from IServiceScopeFactory

public class QueryProcessor : IQueryProcessor
{
private readonly IMediator _mediator;
public QueryProcessor(IServiceScopeFactory serviceScopeFactory)
{
var serviceProvider = serviceScopeFactory.CreateScope().ServiceProvider;
_mediator = new Mediator(serviceProvider);
}
public Task SendAsync(IQuery query,
CancellationToken cancellationToken = default)
{
return _mediator.Send(query, cancellationToken);
}
public IAsyncEnumerable SendAsync(IStreamQuery query,
CancellationToken cancellationToken = default)
{
return _mediator.CreateStream(query, cancellationToken);
}
}