Mongo Csharp Driver doesn't reconnect to MongoDB ReplicaSet

Working with Data Drivers
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1

Hello!
Maybe .NET Driver Version 2.12 will fix this problem, but still it…
I have a .net core project that uses mongodb with 3 replicaset. When there is some network problem the connection is fail, but the mongo csharp driver doesn’t reconnect also after that the network is fixed and broken with memory leak.

here the log:

No connection could be made because the target machine actively refused it. 11.85.70.129:27018
   at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult)
   at System.Net.Sockets.Socket.<>c.<ConnectAsync>b__274_0(IAsyncResult iar)
--- End of stack trace from previous location where exception was thrown ---
   at MongoDB.Driver.Core.Connections.TcpStreamFactory.ConnectAsync(Socket socket, EndPoint endPoint, CancellationToken cancellationToken)
   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: "2021-02-03T08:38:34.8749076Z", LastUpdateTimestamp: "2021-02-03T08:38:34.8749079Z" }, { ServerId: "{ ClusterId : 1, EndPoint : "11.85.70.129:27019" }", EndPoint: "11.85.70.129:27019", 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. 11.85.70.129:27019
   at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult)
   at System.Net.Sockets.Socket.<>c.<ConnectAsync>b__274_0(IAsyncResult iar)
--- End of stack trace from previous location where exception was thrown ---
   at MongoDB.Driver.Core.Connections.TcpStreamFactory.ConnectAsync(Socket socket, EndPoint endPoint, CancellationToken cancellationToken)
   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: "2021-02-03T08:38:33.3437327Z", LastUpdateTimestamp: "2021-02-03T08:38:33.3437330Z" }] }.
   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.Core.Clusters.IClusterExtensions.SelectServerAndPinIfNeeded(ICluster cluster, ICoreSessionHandle session, IServerSelector selector, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Bindings.WritableServerBinding.GetWriteChannelSource(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Bindings.ReadWriteBindingHandle.GetWriteChannelSource(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Operations.RetryableWriteContext.Create(IWriteBinding binding, Boolean retryRequested, CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Operations.BulkMixedWriteOperation.Execute(IWriteBinding binding, CancellationToken cancellationToken)
   at MongoDB.Driver.OperationExecutor.ExecuteWriteOperation[TResult](IWriteBinding binding, IWriteOperation`1 operation, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.ExecuteWriteOperation[TResult](IClientSessionHandle session, IWriteOperation`1 operation, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.BulkWrite(IClientSessionHandle session, IEnumerable`1 requests, BulkWriteOptions options, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.<>c__DisplayClass27_0.<BulkWrite>b__0(IClientSessionHandle session)
   at MongoDB.Driver.MongoCollectionImpl`1.UsingImplicitSession[TResult](Func`2 func, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.BulkWrite(IEnumerable`1 requests, BulkWriteOptions options, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionBase`1.<>c__DisplayClass68_0.<InsertOne>b__0(IEnumerable`1 requests, BulkWriteOptions bulkWriteOptions)
   at MongoDB.Driver.MongoCollectionBase`1.InsertOne(TDocument document, InsertOneOptions options, Action`2 bulkWrite)
   at MongoDB.Driver.MongoCollectionBase`1.InsertOne(TDocument document, InsertOneOptions options, CancellationToken cancellationToken)

There is any solution for this problem?

Thanks a lot

2

Hi @Zoltan_Kovacs,

Welcome to MongoDB community.

Can you share your connection builder settings , pacifically if you set a replicaset name?

Thanks,
Pavel

3

I use this simple connection string:

“mongodb://TestWR:password@11.85.70.129:27017,11.85.70.129:27018,11.85.70.129:27019/?replicaSet=FdApps_Dev&authSource=TestDb”

All of replica members set as priority:1
Maybe I need to add “readPreference=nearest” also?

4

@Zoltan_Kovacs,

According to the the exception both ports refused it.

I think that the machine is not available on all nodes as its the same. machine. This creates a condition there no host is available.

I would suggest to use latest driver and increase socket timeout and server selection time.

Additionally, add retry logic to your application.

Best regards,
Pavel