Igor Fedchenko

Looks like they have published update which includes transaction support: https://www.nuget.org/packages/Confluent.Kafka/1.4.0 So now we can implement missing transactional stages.

@chris-sung Yeah, the problem is that `_producer.InitTransactions` call to Confluent driver is blocking for some reason, and I can't make my PR passing tests. And I ran out of time,...

Hey, nope, this is not resolved - there is a PR (https://github.com/akkadotnet/Akka.Streams.Kafka/pull/196) which was never finished (see comments above). Probably it will work now with latest driver versions, not sure.

@Aaronontheweb Do you think I need to spend time on this right now? On the one hand, this may be occasionally fixed with next PRs (some issues I have already...

Was still reproduced here: https://github.com/akkadotnet/Akka.Streams.Kafka/pull/79/checks?check_run_id=257039068

And once more here: https://dev.azure.com/dotnet/Akka.NET/_build/results?buildId=31981&view=ms.vss-test-web.build-test-results-tab

Looks like there is some issue with `TransactionalProducer.Sink` here - `InitTransactions` call is hanging, which breaks test.

I wrote some short overview about how current scala implementation uses buffering and separate actor for stages implementation [here](https://github.com/akkadotnet/Akka.Streams.Kafka/issues/35#issuecomment-521247203) It looks like we will need to implement something similar in...

@Aaronontheweb So you want to implement some of Transactional Producers? Also, I suspect I will need `FlexiFlow` producer implemented to implement `FlowWithContext` - I will check that out.

All right, now all non-transactional stages in review, and transactional producers are almost implemented, but blocked until #85 is resolved.