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by audnaun252 920 days ago
Modelling domain events is useful for describing the problem your trying to solve with the domain experts, and it should probably be left in the documentation when planning a solution.

For actually implementing a system that provides an audit trail of long-lived state machines, you're probably better off using something like Temporal.io/durable functions which uses event sourcing internally for their persistence, and has a programming model which forces you to think about deduplication/idempotency by adding different constraints for the code that orchestrates the functionality (workflows), vs the code that actually interacts with the real world (activities)
1 comments
DenisM 920 days ago
Durable functions suffer from lack of Observability tho.

I’d love to hear suggestions on overcoming this issue.

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mfateev 920 days ago
temporal.io just released .NET SDK. The observability and scalability of the platform is really good.

Disclaimer: I'm one of the founders of the project.

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rjbwork 919 days ago
Nice to see you dropping in Maxim!

For the GP poster - I agree with Maxim here. We've been evaluating workflow orchestration and durable function systems for a while and finally whittled down to where we think we're going to pull the trigger on either Azure Durable Functions or Temporal. Temporal is really nice - the fact that you are "just writing code" is such a huge bonus over some other stuff like AWS Step Functions, Cadence, and Conductor.

As an aside, the engineering/sales engineering team over there seems top notch.

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DenisM 920 days ago
What I meant specifically is that the current state of a workflow is stored in a format that’s opaque to any component other than the workflow itself.

E.g. if I have a “shopping cart checkout” workflow and the user is not making progress, how can I can I tell which step of the workflow the user is stuck at?

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mfateev 920 days ago
Every step of the workflow is durably recorded. So you have the full information about the exact state of each workflow. To troubleshoot, you can even download the event history and replay workflow in a debugger as many times as needed.

The ease of troubleshooting is one of the frequently cited benefits of the approach.

Check the UI screenshot at https://www.temporal.io/how-it-works.

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audnaun252 920 days ago
The function's event data and current state is all stored in table storage, so you could query that - I'd expect you'd need to query an event-store-based solution in a similar way?
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