使用在 Linux 上运行的 .NET Core 时连接到 MongoDB 失败答案

【问题标题】：Connect to MongoDB failed when using .NET Core running on Linux使用在 Linux 上运行的 .NET Core 时连接到 MongoDB 失败
【发布时间】：2017-12-06 18:30:20
【问题描述】：

我正在使用 ASP.NET Core 2.0（一个月前刚刚从 1.1 升级）构建一个网站。 MongoDB 也由 AWS 上的 Mongo Atlas 托管。这个 MongoDB 实例有 3 个副本集，需要 SSL 连接，并且已经设置可以从任何 IP 访问。

它在我的机器 (Windows 10 x64) 和 AWS (Windows Server 2016) 上运行良好。

我尝试将它部署在 Linux 机器上，我使用 apt 在 Ubuntu Server 16.04 上安装 dotnet-runtime-2.0.0，然后我尝试运行我的站点，并收到以下错误（出于安全原因，我隐藏了确切的服务器域名）

System.TimeoutException: A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = WritableServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/*****-shard-00-00-*****.mongodb.net:27017" }", EndPoint: "Unspecified/*****-shard-00-00-*****.mongodb.net:27017", State: "Disconnected", Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server. ---> MongoDB.Driver.MongoCommandException: Command isMaster failed: no SNI name sent, make sure using a MongoDB 3.4+ driver/shell..

其余副本集出现两个相同的错误。

但是我可以使用同一台机器通过 MongoDB shell 成功连接到 MongoDB 服务器。

是我缺少一些对 Ubuntu 的依赖还是 MongoDB .NET SDK 中存在错误？

完整的堆栈跟踪：

System.TimeoutException: A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = WritableServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/*****-shard-00-00-*****.mongodb.net:27017" }", EndPoint: "Unspecified/*****-shard-00-00-*****.mongodb.net:27017", State: "Disconnected", Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server. ---> MongoDB.Driver.MongoCommandException: Command isMaster failed: no SNI name sent, make sure using a MongoDB 3.4+ driver/shell..
   at MongoDB.Driver.Core.WireProtocol.CommandWireProtocol`1.ProcessReply(ConnectionId connectionId, ReplyMessage`1 reply)
   at MongoDB.Driver.Core.WireProtocol.CommandWireProtocol`1.<ExecuteAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Connections.ConnectionInitializer.<InitializeConnectionAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Connections.BinaryConnection.<OpenHelperAsync>d__48.MoveNext()
   --- End of inner exception stack trace ---
   at MongoDB.Driver.Core.Connections.BinaryConnection.<OpenHelperAsync>d__48.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Servers.ServerMonitor.<HeartbeatAsync>d__27.MoveNext()" }, { ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/*****-shard-00-01-*****.mongodb.net:27017" }", EndPoint: "Unspecified/*****-shard-00-01-*****.mongodb.net:27017", State: "Disconnected", Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server. ---> MongoDB.Driver.MongoCommandException: Command isMaster failed: no SNI name sent, make sure using a MongoDB 3.4+ driver/shell..
   at MongoDB.Driver.Core.WireProtocol.CommandWireProtocol`1.ProcessReply(ConnectionId connectionId, ReplyMessage`1 reply)
   at MongoDB.Driver.Core.WireProtocol.CommandWireProtocol`1.<ExecuteAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Connections.ConnectionInitializer.<InitializeConnectionAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Connections.BinaryConnection.<OpenHelperAsync>d__48.MoveNext()
   --- End of inner exception stack trace ---
   at MongoDB.Driver.Core.Connections.BinaryConnection.<OpenHelperAsync>d__48.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Servers.ServerMonitor.<HeartbeatAsync>d__27.MoveNext()" }, { ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/*****-shard-00-02-*****.mongodb.net:27017" }", EndPoint: "Unspecified/*****-shard-00-02-*****.mongodb.net:27017", State: "Disconnected", Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server. ---> MongoDB.Driver.MongoCommandException: Command isMaster failed: no SNI name sent, make sure using a MongoDB 3.4+ driver/shell..
   at MongoDB.Driver.Core.WireProtocol.CommandWireProtocol`1.ProcessReply(ConnectionId connectionId, ReplyMessage`1 reply)
   at MongoDB.Driver.Core.WireProtocol.CommandWireProtocol`1.<ExecuteAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Connections.ConnectionInitializer.<InitializeConnectionAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Connections.BinaryConnection.<OpenHelperAsync>d__48.MoveNext()
   --- End of inner exception stack trace ---
   at MongoDB.Driver.Core.Connections.BinaryConnection.<OpenHelperAsync>d__48.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MongoDB.Driver.Core.Servers.ServerMonitor.<HeartbeatAsync>d__27.MoveNext()" }] }.
   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.Bindings.WritableServerBinding.GetWriteChannelSource(CancellationToken cancellationToken)
   at MongoDB.Driver.Core.Operations.CreateIndexesOperation.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](IWriteOperation`1 operation, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.MongoIndexManager.CreateMany(IEnumerable`1 models, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoIndexManagerBase`1.CreateOne(IndexKeysDefinition`1 keys, CreateIndexOptions options, CancellationToken cancellationToken)

【问题讨论】：

这部分Command isMaster failed: no SNI name sent, 告诉我们您发送的连接字符串或副本集配置有问题。如果它是 Altas 托管的，并且您使用网站工具来部署副本集而不是自己做，那么它很可能是连接字符串。如果您“确实”进行了自己的副本集配置，而是手动添加了成员和配置，那么这也可能是一个潜在的问题。您应该使用“公共”IP 地址，或者更具体地说，这些主机在 DNS 中分配的名称。
无论如何，您需要查看其中哪一个适用（或两者都适用）并实际提供尽可能多的表示用于您的代码和/或副本集配置的连接字符串.后者可以使用连接到任何成员实例的 mongo shell 从rs.config() 获得。
@NeilLunn 感谢您的回复。我需要解释的是，Mongo Atlas 是官方托管的 MongoDB 服务，我没有执行“rc.config()”命令的权限。最连线的部分是这个项目在 Windows 和 Windows Server 上完美运行，但在 Linux 上出错。但是我可以使用我项目中相同的 MongoDB 连接字符串在 Linux 中通过 MongoDB 命令行工具连接和执行命令。
我们知道 Atlas 是什么。如果您没有权限，那仅仅是因为您使用的帐户没有权限。 MongoDB 不会“锁定”对此的访问，因此您可以安排一个特权帐户。我也告诉你，有几个“可能的原因”。因此，如果配置没有问题，则问题出在您的连接上。无论哪种速度，您都被要求发送至"add detail to your question"，但您尚未完成。所以你找错地方了。不是 Windows 与 Linux，而是“配置”
@YankeeYu 我遇到了同样的错误。在我的 Windows 开发机器上一切正常，但在 linux 上抛出相同的错误。使用连接字符串尝试了不同的选项，但没有运气。你解决了这个问题吗？

标签： .net mongodb asp.net-core .net-core mongodb-.net-driver

【解决方案1】：

.NET Core 库不支持 Linux 和 OSX 上的 SNI TLS 扩展。

因此，您将无法连接到免费层 MongoDB Atlas。

https://docs.atlas.mongodb.com/driver-connection/#c-net-driver-example

重要 .NET Core 库不支持 SNI TLS 扩展在 Linux 和 OSX 上。在这些操作上使用 .NET Core 的应用程序系统无法连接到 Atlas Free Tier 集群。

问题已在dotnet/corefx github page 上跟踪。

【讨论】：

SNI 支持已在 .NET Core 2.1 预览版中实现：github.com/dotnet/corefx/issues/17427 并且使用此补丁 MongoDb 驱动程序可以正常工作。