c# - System.Net.Sockets.SocketException: No such host is known

Question

This is a .netcore 2.2 webapi, mongodb driver 2.11.5. It is trying to connect to MongoDb.

I used to believe that this was a mongodb issue but looking closer at the error message I think that

at System.Net.Dns.HostResolutionEndHelper(IAsyncResult asyncResult)
at System.Net.Dns.EndGetHostAddresses(IAsyncResult asyncResult)
at System.Net.Dns.<>c.<GetHostAddressesAsync>b__25_1(IAsyncResult asyncResult)

is more telling of where the error is occurring. The mongodb server is a linux vm on the network. The .netcore api is running on a windows machine under IIS. A .net app can connect, other tools can connect. So I think is something to do with core.

System.TimeoutException: A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "Automatic", Type : "Unknown", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/?10.29.20.6:27017" }", EndPoint: "Unspecified/?10.29.20.6:27017", ReasonChanged: "Heartbeat", State: "Disconnected", ServerVersion: , TopologyVersion: , Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server. ---> System.Net.Sockets.SocketException: No such host is known
   at System.Net.Dns.HostResolutionEndHelper(IAsyncResult asyncResult)
   at System.Net.Dns.EndGetHostAddresses(IAsyncResult asyncResult)
   at System.Net.Dns.<>c.<GetHostAddressesAsync>b__25_1(IAsyncResult asyncResult)
   at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)
--- End of stack trace from previous location where exception was thrown ---
   at MongoDB.Driver.Core.Connections.TcpStreamFactory.ResolveEndPointsAsync(EndPoint initial)
   at MongoDB.Driver.Core.Connections.TcpStreamFactory.CreateStreamAsync(EndPoint endPoint, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelperAsync(CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelperAsync(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Servers.ServerMonitor.InitializeConnectionAsync(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Servers.ServerMonitor.HeartbeatAsync(CancellationToken cancellationToken)", LastHeartbeatTimestamp: "2021-01-12T00:07:17.1297400Z", LastUpdateTimestamp: "2021-01-12T00:07:17.1297404Z" }] }.
   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.WaitForDescriptionChanged(IServerSelector selector, ClusterDescription description, Task descriptionChangedTask, TimeSpan timeout, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Clusters.Cluster.SelectServer(IServerSelector selector, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoClient.AreSessionsSupportedAfterServerSelection(CancellationToken cancellationToken)
   at MongoDB.Driver.MongoClient.AreSessionsSupported(CancellationToken cancellationToken)
   at MongoDB.Driver.OperationExecutor.StartImplicitSession(CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.UsingImplicitSession[TResult](Func`2 func, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.FindSync[TProjection](FilterDefinition`1 filter, FindOptions`2 options, CancellationToken cancellationToken)
   at MongoDB.Driver.FindFluent`2.ToCursor(CancellationToken cancellationToken)
   at MongoDB.Driver.IAsyncCursorSourceExtensions.Any[TDocument](IAsyncCursorSource`1 source, CancellationToken cancellationToken)
   at Shared.viewer.Repositories.MongoRepository`1.OneExists(Expression`1 where) in C:myproject
epositoriesMongoRepository.cs:line 82
   at WebApi.AssetMngr.Services.AssetService.AssetService.SlideAssetsExist(String slideId) in C:myprojectservicesAssetService.cs:line 142
   at WebApi.AssetMngr.Controllers.AssetsController.SlideAssetsExist(String slideId) in C:myprojectControllersAssetsController.cs:line 150

Both apps are on the same IIS server. (Both apps actually work on our demo server)

Just wondering if anyone has hit such an issue. Is the timeout a red herring and there is actually another issue?

Gina

Answer 1

等待大神解答