[[blog/video-event-sourcing-you-are-doing-it-wrong-david-schmitz.md|Video_ Event Sourcing You are doing it wrong - David Schmitz]] Want to Read Rate this book 1 of 5 stars2 of 5 stars3 of 5 stars4 of 5 stars5 of 5 stars Versioning in an Event Sourced System by Greg Young 4.11 · https://www.goodreads.com/book/show/34327067-versioning-in-an-event-sourced-system?from_search=true#https://www.goodreads.com/book/show/34327067-versioning-in-an-event-sourced-system?from_search=true# https://www.goodreads.com/book/show/34327067-versioning-in-an-event-sourced-system?from_search=true# Rating details · 9 ratings · 3 reviews Why Version? Have you ever done a big bang release? You schedule a maintenance window, carefully take down the system, release the new software, and… pray. I will never do a big bang release again. What scares me is not what happens if the release does not work, but what happens if it does not work and yet still appears to. Most developers, even those working through big bang releases, have dealt with the versioning of software before. For example, they write SQL migration scripts to convert the old schema to the new one. But have you ever written SQL migration scripts to convert from the new schema with data added to it back to the old schema without losing information? What happens if, later, you get a catastrophic failure on the new release? On teams I have worked with in the past, you got your choice: the fireman helmet or the cowboy hat. In other words, the fireman helmet means if you are working on a production issue, people know not bother you unless they have something material to your issue. I highly recommend this, as at least you get to keep a smile on your face while you are working live in production. To be fair, who wouldn’t want to wear a fireman helmet at work? In modern systems, however, this is not acceptable. The days of maintenance windows and big bang releases are over. Instead, we now focus on releasing parts of software, and often end up wanting to run multiple versions of software side by side. We can no longer update every consumer when a producer is released. We are forced to deal with versioning issues. We are forced to deal with 24/7/365 operations. There are many forces pushing us in this direction. We could talk about the move towards SOA/MicroServices, Continuous Deployment, core ideas from the business side, lossed opportunities and reputational risk. Many of the strategies discussed apply to messaging systems in general. Event Sourced systems also face these kinds of versioning issues in a unique way, as they represent an append-only model. A projection, for instance, needs to be able to read an event that was written two years ago, even though use-cases may have changed. What happens when you have mistakenly written an event in production? If we are to say an event is immutable and the model is append-only, many complications arise. Over the years, I have met many developers who run into issues dealing with versioning, particularly in Event Sourced systems. This seems odd to me. As we will discuss, Event Sourced systems are in fact easier to version than structural data in most instances, as long as you know the patterns for how to version, where they apply, and the trade-offs between the options. (less) Get A Copy AmazonOnline Stores ▾Book Links ▾ ebook, v10 5/4/17 Published April 5th 2017 by Leanpub Edition Language English . URL https://leanpub.com/esversioning/read . Other Editions None found All Editions | Add a New Edition | Combine …Less Detail edit details Edit My Activity Review of Versioning in an Event Sourced System (ebook) Rating 1 of 5 stars2 of 5 stars3 of 5 stars4 of 5 stars5 of 5 stars Shelves to-read edit( 261st ) Format ebook edit Status March 4, 2017 – Shelved as: to-read March 4, 2017 – Shelved Review Add a review comment . Friend Reviews (4) Feb 19, 2017 Thomas added it Like · comment Feb 20, 2017 Gien Verschatse marked it as to-read Shelves: non-fiction, programming, 2018 flag Like · comment Feb 19, 2017 Guido added it Shelves: software flag Like · comment Feb 21, 2017 Koen Metsu marked it as to-read Like · comment Recommend This Book… . Reader Q&A Ask the Goodreads community a question about Versioning in an Event Sourced System ![[./resources/book-versioning-in-an-event-sourced-system-greg-yo.resources/30721486.ux100_cr00100100.jpg]] Be the first to ask a question about Versioning in an Event Sourced System . Lists with This Book This book is not yet featured on Listopia. Add this book to your favorite list » . Community Reviews Showing 1-41 4.11 · https://www.goodreads.com/book/show/34327067-versioning-in-an-event-sourced-system?from_search=true# Rating details · 9 ratings · 3 reviews ![[./resources/book-versioning-in-an-event-sourced-system-greg-yo.resources/loading-45f04d682f1e9151cf1e6fb18a1bde21.gif]] https://www.goodreads.com/book/show/34327067-versioning-in-an-event-sourced-system?from_search=true#Filter | https://www.goodreads.com/book/show/34327067-versioning-in-an-event-sourced-system?from_search=true#Sort order . Apr 13, 2017 Sebastian Gebski added it Disclaimer: this review is based on early version of the book (~70%). All the chapters are already in place, but book needs a lot of polishing (e.g. pictures & drawings are either temps or missing). When I’ve found out that Greg Young is writing a book on event sourcing, I knew I’d have to read it. Not because I’m any kind of his fanboy (yes, he has some) or because there are so few (any?) books on the topic. I was hooked up by the idea of the book that doesn’t just cover ES, but focuses on a …more flag 1 like · Like · comment · see review Feb 17, 2017 Jorn rated it it was amazing Greg Young explains various ways of versioning events. His expertise on the subject gave me quite a few new insights. I can recommend it for everyone building or looking to build an event sourced system. flag Like · comment · see review Mar 01, 2018 🦆 added it The echo chamber has decided that this is the 2nd book you should read on the topic of event sourcing and I agree. I’m still unsure what the first should be. flag Like · comment · see review Matt Thornton rated it liked it Mar 09, 2019 Matteo Baglini rated it really liked it Dec 05, 2018 Andy rated it really liked it Jun 14, 2017 Volkan rated it really liked it Apr 30, 2018 Kacper Gunia rated it really liked it Apr 25, 2017 Craig rated it it was amazing Jan 04, 2019 Krzysztof rated it really liked it Oct 28, 2018 Magnus Lidbom rated it really liked it Sep 18, 2018 Guido added it Feb 19, 2017 Thomas added it Feb 19, 2017 Jan Van Ryswyck marked it as to-read Feb 19, 2017 Christiaan Van den Poel marked it as to-read Feb 19, 2017 Gien Verschatse marked it as to-read Feb 20, 2017 Marek marked it as to-read Feb 20, 2017 Koen Metsu marked it as to-read Feb 21, 2017 Antonios Klimis marked it as to-read Feb 22, 2017 Max Voloshin marked it as to-read Feb 26, 2017 Daniel Konishi marked it as to-read Feb 28, 2017 Ilya Palkin marked it as to-read Feb 28, 2017 Felipe marked it as to-read Mar 02, 2017 Lucianna marked it as to-read Mar 03, 2017 Tjen Wellens marked it as to-read Mar 04, 2017 Marco Emrich marked it as to-read Mar 05, 2017 Leonardo Bessa marked it as to-read Mar 05, 2017 Patrik Herrgård added it Apr 07, 2017 Sasha Argunov is currently reading it Apr 10, 2017 Mirosław marked it as to-read Apr 11, 2017 Mirosław Pragłowski added it Apr 11, 2017 Artur marked it as to-read Apr 13, 2017 Anurag Sharma marked it as to-read Apr 25, 2017 Zach Boyle marked it as to-read Apr 28, 2017 Szymon Skowroński marked it as to-read May 04, 2017 Sergio Silveira marked it as to-read May 28, 2017 Piotr marked it as to-read Jun 04, 2017 Ekaterina Egorova marked it as to-read Jun 20, 2017 Kamil marked it as to-read Jun 21, 2017 Lukasz Strzelecki marked it as to-read Jun 22, 2017 mpi marked it as to-read Jun 23, 2017 . new topic Discuss This Book There are no discussion topics on this book yet. 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