MongoDB Atlas - ASP.NET Core 6.0 System.TimeoutException:

MongoDB Atlas
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1

I am getting a “System.TimeoutException: A timeout occurred after 30000ms selecting a server using CompositeServerSelector” error when trying to connect to MongoDB Atlas from an ASP.NET Core 6.0 application.

I am able to connect and do CRUD operations using the mongosh command line shell with no issues.

I have also set IP configuration to all “0.0.0.0/0” in the network settings.

Connection string is:

mongodb+srv://:@cluster0.fpgve4z.mongodb.net/?retryWrites=true&w=majority

I am using MongoDB.Driver v2.17.1

Any help is very much appreciated!

Thanks!

Exception Stack

System.TimeoutException: A timeout occurred after 30000ms selecting a server using CompositeServerSelector{ Selectors = MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 }, OperationsCountServerSelector }. Client view of cluster state is { ClusterId : "2", Type : "Unknown", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 2, EndPoint : "Unspecified/localhost:27017" }", EndPoint: "Unspecified/localhost:27017", ReasonChanged: "Heartbeat", State: "Disconnected", ServerVersion: , TopologyVersion: , Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server.
 ---> System.Net.Internals.SocketExceptionFactory+ExtendedSocketException (10061): No connection could be made because the target machine actively refused it. [::1]:27017
   at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
   at MongoDB.Driver.Core.Connections.TcpStreamFactory.Connect(Socket socket, EndPoint endPoint, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Connections.TcpStreamFactory.CreateStream(EndPoint endPoint, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelper(CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelper(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Connections.BinaryConnection.Open(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Servers.ServerMonitor.InitializeConnection(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Servers.ServerMonitor.Heartbeat(CancellationToken cancellationToken)", LastHeartbeatTimestamp: "2022-10-07T19:23:18.1503545Z", LastUpdateTimestamp: "2022-10-07T19:23:18.1503546Z" }] }.
   at MongoDB.Driver.Core.Clusters.Cluster.ThrowTimeoutException(IServerSelector selector, ClusterDescription description)
   at MongoDB.Driver.Core.Clusters.Cluster.WaitForDescriptionChangedHelper.HandleCompletedTask(Task completedTask)
   at MongoDB.Driver.Core.Clusters.Cluster.WaitForDescriptionChangedAsync(IServerSelector selector, ClusterDescription description, Task descriptionChangedTask, TimeSpan timeout, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Clusters.Cluster.SelectServerAsync(IServerSelector selector, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoClient.AreSessionsSupportedAfterServerSelectionAsync(CancellationToken cancellationToken)
   at MongoDB.Driver.MongoClient.AreSessionsSupportedAsync(CancellationToken cancellationToken)
   at MongoDB.Driver.MongoClient.StartImplicitSessionAsync(CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.UsingImplicitSessionAsync[TResult](Func`2 funcAsync, CancellationToken cancellationToken)
   at MongoDB.Driver.IAsyncCursorSourceExtensions.ToListAsync[TDocument](IAsyncCursorSource`1 source, CancellationToken cancellationToken)
   at Brewery.Services.BreweryInformationService.GetAsync() in C:\BrewerySimulator\BrewerySimulator\Brewery.Services\BreweryInformationService.cs:line 21
   at BreweryLab.API.Controllers.LocationTypeController.Get() in C:\BrewerySimulator\BrewerySimulator\BreweryLab.API\Controllers\LocationTypeController.cs:line 20
   at lambda_method5(Closure , Object )
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>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>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
   at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

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Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Referer: http://localhost:5183/swagger/index.html
sec-ch-ua: "Chromium";v="106", "Google Chrome";v="106", "Not;A=Brand";v="99"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Windows"
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
3

Hi @Don_King, and welcome to the MongoDB Community forums! :wave:

I don’t code in .NET, but your exception stack mentions localhost and :::1. It looks like your application is trying to connect to a local instance of MongoDB instead of the Atlas cluster.

You could try sharing a minimal application that exhibits this problem and someone knowledgeable in .NET might be able to point out what’s going on.

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