InvalidCastException after adding CAP to existing, multi-project solution

[flipdoubt]

After adding DotNeteCore.Cap.SqlServer to our solution where other projects reference other packages, using EF Core 5.0.2 to insert records from non-CAP code succeeds and then produces the error shown below. I see that they point to different folders in my local nuget cache but I do not know how to unify the references because I have no code that directly references 2.0.1 or 2.1.2.

Can you suggest how I can unify the references? Is there some way to disable DiagnosticObserver or prevent it from interfering with EF Core?

TYPE: System.InvalidCastException
MSG: [A]Microsoft.Data.SqlClient.SqlConnection cannot be cast to [B]Microsoft.Data.SqlClient.SqlConnection.
Type A originates from 'Microsoft.Data.SqlClient, Version=2.0.20168.4, Culture=neutral, PublicKeyToken=23ec7fc2d6eaa4a5' in the context 'Default' at location 'C:\Users\me\.nuget\packages\microsoft.data.sqlclient\2.0.1\
runtimes\win\lib\netcoreapp3.1\Microsoft.Data.SqlClient.dll'.
Type B originates from 'Microsoft.Data.SqlClient, Version=2.0.20168.4, Culture=neutral, PublicKeyToken=23ec7fc2d6eaa4a5' in the context 'Default' at location 'C:\Users\me\.nuget\packages\microsoft.data.sqlclient\2.1.2\runtimes\win\lib\netcoreapp3.1\Microsoft.Data.
SqlClient.dll'.
   at DotNetCore.CAP.SqlServer.Diagnostics.DiagnosticObserver.OnNext(KeyValuePair`2 evt) in C:\projects\cap\src\DotNetCore.CAP.SqlServer\Diagnostics\DiagnosticObserver.cs:line 41
   at System.Diagnostics.DiagnosticListener.Write(String name, Object value)
   at Microsoft.Data.SqlClient.SqlClientDiagnosticListenerExtensions.WriteTransactionCommitAfter(SqlDiagnosticListener this, Guid operationId, IsolationLevel isolationLevel, SqlConnection connection, SqlInternalTransac
tion transaction, String operation) in H:\tsaagent1\_work\21\s\src\Microsoft.Data.SqlClient\netcore\src\Microsoft\Data\SqlClient\SqlClientDiagnosticListenerExtensions.cs:line 253
   at Microsoft.Data.SqlClient.SqlTransaction.Commit() in H:\tsaagent1\_work\21\s\src\Microsoft.Data.SqlClient\netcore\src\Microsoft\Data\SqlClient\SqlTransaction.cs:line 182
   at Microsoft.EntityFrameworkCore.Storage.RelationalTransaction.Commit()

[xiangxiren]

Maybe you should refer to the same EFCore as the dependency version of DotNetCore.CAP.SqlServer

[flipdoubt]

@xiangxiren, thanks for the reply. I just tried that and got the same error. The problem appears to be that I reference Microsoft.EntityFrameworkCore.SqlServer, which references the older Microsoft.Data.SqlClient 2.0.1. Even EF Core 5.0.5 references Microsoft.Data.SqlClient 2.0.1. I have to go all the way to EF Core 6.0.0-preview.3.21201.2 to get Microsoft.Data.SqlClient 2.1.2.

I also tried referencing Microsoft.Data.SqlClient 2.1.2 directly, but that doesn't fix it.

[flipdoubt]

I don't use CAP with EF Core, so I tried downgrading to DotNetCore.Cap.SqlServer 3.1.2 which uses Microsoft.Data.SqlClient 2.0.1. This appears to fix my issue, though I'm still testing.

[yang-xiaodong]

Hello David,

It seems that this is due to the conflict caused by Microsoft.EntityFrameworkCore.SqlServer and DotNetCore.CAP.SqlServer use different versions of Microsoft.Data.SqlClient.

In theory, referencing the new version of Microsoft.Data.SqlClient in the project can resolve the conflict. If you can’t solve this problem, we can consider downgrading Microsoft.Data.SqlClient to 2.0.1

[flipdoubt]

Our project that uses Microsoft.EntityFrameworkCore.SqlServer 5.0.4 now references Microsoft.Data.SqlClient 2.1.2 explicitly, though it does not use it, and still gets the System.InvalidCastException "at DotNetCore.CAP.SqlServer.Diagnostics.DiagnosticObserver.OnNext(KeyValuePair`2 evt) in C:\projects\cap\src\DotNetCore.CAP.SqlServer\Diagnostics\DiagnosticObserver.cs: line 41."

I suspect we get this error due to the fact that we dynamically load each of these projects as plugins that implement interfaces from a shared contracts library. We use other components that reference older versions, like Serilog MSSqlServer which depends on Microsoft.Data.SqlClient >= 1.1.3 but have never had this problem until we added DotNetCore.CAP.SqlServer. Odd that it only occurs after a "write transaction" that does not even involve CAP.

Curious as to why Microsoft.EntityFrameworkCore.SqlServer 5.0.4 does not use Microsoft.Data.SqlClient 2.1.2 and what this version gives CAP that 2.0.1 does not. Any insights?

It would be great if you considered downgrading if 2.1.2 doesn't provide new functionality other than "latest and greatest", but I suspect DiagnosticObserver.cs line 41 does something none of the other dependencies do and may even require 2.1.2. We have not used it directly.

[yang-xiaodong]

Hello David,

We have downgraded Microsoft.Data.SQLClient to 2.0.1, you can try with the preview version 5.0.2-preview-136113481.

Thanks for your feedback

[flipdoubt]

@yang-xiaodong, tested and confirmed it works with 5.0.2-preview-136113481.