Question

我最近启动了一个使用Entity Framework Core进行数据库通信的ASP.NET核心Web应用程序（WebAPI），只要我在我的开发环境中在笔记本电脑上运行应用程序，一切都运行得非常顺利。

使用Ubuntu服务器（16.04.3 LTS）托管Web应用程序和数据库。我安装了最新的sql server（Microsoft SQL Server 2017（RC2） - 14.0.900.75（X64）），只要应用程序在windows上运行，我就可以从我的应用程序连接到它。但是，在Ubuntu上使用相同的代码和连接字符串，所有查询都会超时。我得到以下输出（异常/堆栈跟踪）：

fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HL6RV4D2F9I6": An unhandled exception was thrown by the application.
System.Data.SqlClient.SqlException: Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding. ---> System.ComponentModel.Win32Exception: Unknown error 258
   --- End of inner exception stack trace ---
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
   at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error)
   at System.Data.SqlClient.TdsParserStateObject.ReadSniSyncOverAsync()
   at System.Data.SqlClient.TdsParserStateObject.TryReadNetworkPacket()
   at System.Data.SqlClient.TdsParserStateObject.TryPrepareBuffer()
   at System.Data.SqlClient.TdsParserStateObject.TryReadByteArray(Byte[] buff, Int32 offset, Int32 len, Int32& totalRead)
   at System.Data.SqlClient.TdsParserStateObject.TryReadChar(Char& value)
   at System.Data.SqlClient.TdsParser.TryReadPlpUnicodeCharsChunk(Char[] buff, Int32 offst, Int32 len, TdsParserStateObject stateObj, Int32& charsRead)
   at System.Data.SqlClient.TdsParser.TryReadPlpUnicodeChars(Char[]& buff, Int32 offst, Int32 len, TdsParserStateObject stateObj, Int32& totalCharsRead)
   at System.Data.SqlClient.TdsParser.TryReadSqlStringValue(SqlBuffer value, Byte type, Int32 length, Encoding encoding, Boolean isPlp, TdsParserStateObject stateObj)
   at System.Data.SqlClient.TdsParser.TryReadSqlValue(SqlBuffer value, SqlMetaDataPriv md, Int32 length, TdsParserStateObject stateObj)
   at System.Data.SqlClient.SqlDataReader.TryReadColumnInternal(Int32 i, Boolean readHeaderOnly)
   at System.Data.SqlClient.SqlDataReader.GetValues(Object[] values)
   at Microsoft.EntityFrameworkCore.Storage.Internal.UntypedRelationalValueBufferFactory.Create(DbDataReader dataReader)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable.Enumerator.BufferlessMoveNext(Boolean buffer)
   at Microsoft.EntityFrameworkCore.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](Func`2 operation, Func`2 verifySucceeded, TState state)
   at Microsoft.EntityFrameworkCore.Query.QueryMethodProvider.<_ShapedQuery>d__3`1.MoveNext()
   at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
   at lambda_method(Closure , QueryContext )
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass20_0`1.<CompileQueryCore>b__0(QueryContext qc)
   at System.Linq.Queryable.First[TSource](IQueryable`1 source, Expression`1 predicate)
   at Considition.WebAPI.Controllers.GameController.InitiateGame(String apikey) in /home/fredrik/WebApps/Considition/Considition.WebAPI/Controllers/GameController.cs:line 70
   at lambda_method(Closure , Object , Object[] )
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionMethodAsync>d__27.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 Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextActionFilterAsync>d__25.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextResourceFilter>d__22.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ResourceExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeAsync>d__20.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 Microsoft.AspNetCore.Builder.RouterMiddleware.<Invoke>d__4.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 Microsoft.AspNetCore.Cors.Infrastructure.CorsMiddleware.<Invoke>d__7.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 Microsoft.AspNetCore.Hosting.Internal.RequestServicesContainerMiddleware.<Invoke>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 Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame`1.<RequestProcessingAsync>d__2.MoveNext()
ClientConnectionId:19a604ef-758e-4797-8780-6b95dcbfdd17
Error Number:-2,State:0,Class:11
info: Microsoft.AspNetCore.Hosting.Internal.WebHost[2]
      Request finished in 35515.1854ms 500

我的代码中发生异常的行是：

var teamGameState = ctx.GeneratedGameStates.First(x => x.TeamId == teamId);

该表只有一个条目并且在SSMS中查看Activity Monitor，我可以看到翻译的sql类似于（SELECT TOP 1 * FROM ...）并且查询花了35秒。

我一直在阅读其他有类似问题的人在试图从linux连接到sql server时使用相同的代码从windows工作正常，但我找不到解决方案。

是否有其他人遇到此问题，更重要的是有人解决了这个问题？

Answer 1

我认为这是重复的： https://github.com/aspnet/EntityFrameworkCore/issues/5989

解决方案：更新服务器软件，因为您使用的是RC2。

Answer 2

我在Azure上的Docker容器中的Linux下在Linux下运行SQL-Server 2019时遇到类似的问题。简单选择查询经常会超时，但大多数情况下都可以正常工作。

执行超时已过期。逾时时间已过操作完成或服务器没有响应。

使用的图像： mcr.microsoft.com/mssql/server:2019-CU4-ubuntu-16.04

我正在从 .net核心应用进行查询。

我看到有一个新图像可用， CU5 ，我将尝试该图像，看看问题是否仍然存在。

在Linux

2 个答案: