A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = ReadPreferenceServerSelector{ ReadPreference = { Mode : Primary } }, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "ReplicaSet", Type : "ReplicaSet", State : "Connected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/mongodb-replicaset-samlib-0.mongodb-replicaset-samlib.mongodb-replicaset-samlib.svc.cluster.local:27017" }", EndPoint: "Unspecified/mongodb-replicaset-samlib-0.mongodb-replicaset-samlib.mongodb-replicaset-samlib.svc.cluster.local:27017", State: "Connected", Type: "ReplicaSetSecondary", WireVersionRange: "[0, 6]" }, { ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/mongodb-replicaset-samlib-1.mongodb-replicaset-samlib.mongodb-replicaset-samlib.svc.cluster.local:27017" }", EndPoint: "Unspecified/mongodb-replicaset-samlib-1.mongodb-replicaset-samlib.mongodb-replicaset-samlib.svc.cluster.local:27017", State: "Connected", Type: "ReplicaSetSecondary", WireVersionRange: "[0, 6]" }, { ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/mongodb-replicaset-samlib-2.mongodb-replicaset-samlib.mongodb-replicaset-samlib.svc.cluster.local:27017" }", EndPoint: "Unspecified/mongodb-replicaset-samlib-2.mongodb-replicaset-samlib.mongodb-replicaset-samlib.svc.cluster.local:27017", State: "Disconnected", Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server. ---> System.Net.Internals.SocketExceptionFactory+ExtendedSocketException: No such device or address at System.Net.Dns.InternalGetHostByName(String hostName) at System.Net.Dns.ResolveCallback(Object context) --- End of stack trace from previous location where exception was thrown --- 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.HeartbeatAsync(CancellationToken cancellationToken)" }] }.