Outcome enlistment handle leak in `OletxTransactionManager`

[swh-cb]

After the transaction has been completed or aborted, the outcome enlistment handle in OletxTransactionManager must be released again.

[caviyacht]

@swh-cb , Is this project still active? We are currently upgrading to .NET 6 and I would like to utilize this library, but was concerned with a potential leak. Is this leak a huge issue, or just something that needs to be cleaned up?

[swh-cb]

The issue must be fixed but does not affect productive use of the library.

We still use the library in our products targeting .NET 6 without problems. Once .NET 8 is released with long term support (LTS), we will probably switch back to System.Transactions. .NET 7 added distributed transaction support for Windows only (dotnet/runtime#72051). However, you need the latest version of Microsoft.Data.SqlClient to avoid deadlocks with MSSQL (dotnet/SqlClient#1801). If an Oracle database is to participate in the transaction, the OletxCompatibilityLoadContext is still required in combination with the unmanaged ODP.NET driver Oracle.DataAccess. There is an open feature request for distributed transaction support in ODP.NET Core on .NET 7 and Windows (oracle/dotnet-db-samples#267).

[caviyacht]

@swh-cb , Thanks for responding so quickly. Ok, so sounds like we should be good to use this (I believe). We will be on .NET 6 for the foreseeable future (tied to a 3rd party framework).

We are using the latest version of System.Data.SqlClient (v4.8.5). I was wondering, the Sql patch logic that you recommend ( MsSqlPatcher.Patch(typeof(SqlConnection).Assembly);), is that still needed for this version as well? I'm going to assume yes.

[swh-cb]

@caviyacht Exactly, System.Data.SqlClient needs to be patched, even for the latest version 4.8.5. The fix from dotnet/SqlClient#1624 for Microsoft.Data.SqlClient was not backported. We are currently using the (patched) version 4.1.0 of Microsoft.Data.SqlClient in our environments.

[swh-cb]

This issue won't be fixed because distributed transactions are supported on Windows starting with .NET 7.0.