Runtime: Implement distributed/promoted transactions in System.Transactions.

[jimcarley]

Issue moved to dotnet/runtime dotnet/runtime#14099

[XieJJ99]

@ajcvickers @stephentoub The SQL Server team had already provided MSDTC for SQL Server on Linux. Is there any plan to promote the MSDTC for linux as a generic service so that it's possible to support distributed transaction on Linux?

[ULSTechology]

A lack of support for distributed transactions is pretty disastrous for anyone wanting to migrate their old system onto .NET Core.

This puts an end to our hopes that we can start using Blazor - we can't rewrite our entire application to work without distributed transactions, there's just too much of it.

[popcatalin81]

we can't rewrite our entire application to work without transactions, there's just too much of it.

Surely, if you can rewrite for Blazor, which is a significant rewrite anyway, you can also eliminate distributed transactions.

[ULSTechology]

we can't rewrite our entire application to work without transactions, there's just too much of it.

Surely, if you can rewrite for Blazor, which is a significant rewrite anyway, you can also eliminate distributed transactions.

Using Blazor requires a rewrite of the UI, and we can start small with that.

Rewriting some fairly large chunks of our data access layer, and probably even some of our business layer, is a whole other matter. Unfortunately, it's not an option we could consider at the moment.

[mmaderic]

I would like to vote up for this feature at least for databases on single SQL server instance.

I have case where I would like to enclose two different database commits into single system transaction. (Sort of micro-service architecture).

[abbotware]

@LaterStart - I have the same use case so +1

Creating multiple exe microservices (service fabric) sharing a single SQL database (migration of legacy code / data)

I found it is possible on Net Core to share transactions/connections between ADO. and EF Core within a single process (https://docs.microsoft.com/en-us/ef/core/saving/transactions) ,

However, what options currently exist when 2 separate Net Core exes are involved for implementing a 2 phase-commit like pattern?

1. Can the DTC / Resource Manager be simulated via base classes in Net Standard? (https://docs.microsoft.com/en-us/previous-versions/ms229975(v=vs.90))

2. Call the DTC directly via Win32 Api and some how enlist?

1-2 seem like a lot of work, but from what I have read (somewhere) I could just target Net Standard 2.0 and run within a Net Framework host - That will allow System.Transactions to enlist / promote into a DTC transaction, (I can settle for Netstandard + 4.7.2 + new sdk project format if that is my only option)

Even if I use a Net Framework Host (or Net Core if this open issue ever gets implemented), does that mean it should it is possible to obtain the transaction token / correlation id from process A so it can be sent/serialized to process B for manual enlistment?

[pappasa]

How do you use .NET Core with IBM WebSphere MQ queue? For example, I do not want to remove the message from the queue, and the put to the database to fail.

[aajmot]

can someone tell me if the issue has been fix or still there?
It's almost 2020 now?
Is there any other way around, please tell me.

[pi3k14]

@dasetser
wtf - you moved this into the unforeseeable future?
Don't you want to on-board enterprise solutions to .Net Core, you want to push us all over to the dark side (java)?

[am11]

Going by https://referencesource.microsoft.com/#System.Transactions/System/Transactions/Oletx/DTCTransactionManager.cs,2c1154236b6b7acf, seems like there are some win32 specific components involved which probably is the main hurdle. Could someone shed light on what are those and what would require to bring them cross platform?

[dasetser]

This got moved to future because after investigating it we determined it's going to be a significant rewrite of the feature rather than just a port. We're looking into options for this, but we aren't able to commit to getting this done in the upcoming release.

The main hurdle is that System.Transactions depends on MSDTC when it has to promote transactions, but MSDTC is only available on Windows. In order to get this to work cross platform we would need to rewrite the feature to allow it to work with other distributed transaction coordinators that are available on other platforms, or look into doing something similar to what the SQL Server team did where they brought the DTC components inside the SQL component. Either approach would be a significant change to this feature.

[Peperud]

Where do I vote for this?

[pi3k14]

@dasetser - I appreciate your clarification.
But, us current users of Distributed transactions don't care about cross platform.
Just support it on Windows, and put this cross platform paradigm that we haven't request into the future.

Thank you.

[am11]

Thanks for the explanation @dasetser.
If the target linux machine has MSDTC component from SQL Server installed, and its C API is the same as Windows, can the implementation take advantage -- as in, SQL Server as a prerequisite (for now)? We can separately request and poll SQL Server team to ship MSDTC component as a standalone library. :)

[randyburden]

We were planning to begin porting many of our current applications to .NET Core starting next week as well as start writing our new apps on .NET Core but we just ran into this issue of distributed transactions not working which feels like a deal breaker. Almost every application we write or will write in the future requires distributed transactions.

It is very odd to have experienced a platform not supported exception with this particular feature when we all know that it already exists in the full .NET Framework. It's hard to understand why a Windows platform specific implementation wasn't implemented either in CoreFX or as a shim NuGet package.

Is there a workaround?

[pi3k14]

@dasetser - Wouldn't implementing WS-AtomicTransaction be the way to go. And since MSDTC supports it and WCF has an implementation of it https://docs.microsoft.com/en-us/dotnet/framework/wcf/feature-details/using-ws-atomictransaction this shouldn't take that much time. Those wanting distributed transactions on Unix can then get a third party solution.

[StephenBonikowsky]

Issue moved to dotnet/runtime dotnet/runtime#14099 via ZenHub