19.09.2017 I shall say it only once with Szymon Pobiega



After a long summer break, we will be back with a geeky topic related to Distributed Systems. This is yet another fantastic collaboration event together with the .NET Usergroup Bern. Daniel’s good friend and co-worker Szymon Pobiega will be in town delivering interesting insights into Idempotency in Distributed Systems. Don’t miss this one!

We are still looking for interesting short presentations for our usergroup meetings. Short presentations are the ideal format to give away your insights about the latest tools and techniques you use in your daily job. It is also a very good platform to sharpen your presenter skills. Send us an email to urs dot enzler at dotnet-zentral.ch or daniel dot marbach at dotnet-zentral.ch. Take the chance: you can give it in German or English!


1. Introduction
2. Intro:  Not yet defined
3. Main: I shall say it only once with Szymon Pobiega
4. Knowledge Exchange/Apéro


bbv Software Services AG, Blumenrain 10, Luzern, 1. Stock
(Details siehe http://www.dotnet-zentral.ch/?page_id=98)


6 PM – 8:30/9:00 PM (After that apero)



I shall say it only once

And you shall do it only once. Exactly once. That’s a very common assumption for most of business software. One trigger equals one outcome. As it turns out, it is easier said than done.
One way to solve the problem is to prevent messages from getting duplicated in the first place. This requires transactions spanning data stores and messaging systems which is neither fast nor widely available.
Another way is taking advantage of natural idempotency of some operations, e.g. setting a value. But let’s face it, most business code is more complex than that.
As a third option, I’ll show you the *Outbox* pattern which makes distributed transaction look like a rusty old timer. Join me in this talk and make sure you’ll never refund a customer twice, again.

Szymon Pobiega

Szymon Pobiega used to build various kinds of custom software systems, from banks and airlines to bitcoin exchanges, only to figure out his true passion lies in the stuff that is hidden from user’s eyes — the infrastructure on which the business software runs. Now, as a software engineer at Particular, the makers of NServiceBus, Szymon found his happy place where he focuses on message routing patterns in distributed systems.
When tired with coding, Szymon enjoys building remotely controlled Lego all-terrain vehicles.


By using our xing group dotnet-zentral or our website under Anmeldung. Attention: Seats are limited!

Come and visit the next meeting of the .NET Usergroup Zentralschweiz.

Urs Enzler and Daniel Marbach

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By daniel.marbach