efcore: A transport-level error has occurred when receiving results from the server. (provider: Session Provider, error: 19 - Physical connection is not usable)

Hi All,

In our production environment we see sporadic exceptions stating A transport-level error has occurred when receiving results from the server. (provider: Session Provider, error: 19 - Physical connection is not usable).

At the moment we’re using a pretty simple connection string:

Server=172.24.32.7;Database=GetYourPet_1_1_0;User Id=***;Password=***;MultipleActiveResultSets=true

The database server is a separate machine from the web server, so there is networking involved. So I’m not sure why the connections go down in the first place, but then I’m wondering if there’s a way to catch this exception more generically and retry? And / or should we have more specific settings in the connection string about the size of the connection pool?

Sort of desperate here… any help would be great.

If you are seeing an exception, include the full exceptions details (message and stack trace).

Exception message: A transport-level error has occurred when receiving results from the server. (provider: Session Provider, error: 19 - Physical connection is not usable)
Stack trace:
at System.Data.SqlClient.SqlConnection.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.TryReadByte(Byte& value) ~    
at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) ~    
at System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() ~    
at System.Data.SqlClient.SqlDataReader.get_MetaData() ~    
at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) ~    
at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds, Boolean describeParameterEncryptionRequest) ~    
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) ~    
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) ~    
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) ~    
at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(IRelationalConnection connection, String executeMethod, IReadOnlyDictionary`2 parameterValues, Boolean closeConnection) ~    
at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteReader(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues) ~    
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.FirstOrDefault[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 GetYourPet.Services.MeetUpService.Get(String adopterUserId, Int32 petId, ApplicationUserRole applicationUserRole) in D:\a\1\s\GetYourPet\src\GetYourPet\Services\MeetUpService.cs:line 45 ~    
at GetYourPet.Controllers.MeetUpsController.Get(String adopterUserId, Int32 petId) in D:\a\1\s\GetYourPet\src\GetYourPet\Controllers\MeetUpsController.cs:line 63

Steps to reproduce

There are no deterministic steps to reproduce

line 45 from MeetUpService.cs:

MeetUp meetUp = _applicationDbContext.MeetUps.Where(mu => mu.AdopterUserId == adopterUserId && mu.PetId == petId).FirstOrDefault();

Further technical details

EF Core version: 1.1.0 Database Provider: Microsoft.EntityFrameworkCore.SqlServer Operating system: Windows Server 2012 R2 IDE: Visual Studio 2015 w/ Update 3 (but that’s just what we develop with… the issue is occurring in our production environment)