The Art of Immutable Architecture: Theory and Practice of Data Management in Distributed Systems

This book teaches you how to evaluate a distributed system from the perspective of immutable objects. You will understand the problems in existing designs, know how to make small modifications to correct those problems, and learn to apply the principles of immutable architecture to your tools.

Most software components focus on the state of objects. They store the current state of a row in a relational database. They track changes to state over time, making several basic assumptions: there is a single latest version of each object, the state of an object changes sequentially, and a system of record exists.
This is a challenge when it comes to building distributed systems. Whether dealing with autonomous microservices or disconnected mobile apps, many of the problems we try to solve come down to synchronizing an ever-changing state between isolated components. Distributed systems would be a lot easier to build if objects could not change.
After reading The Art of Immutable Architecture, you will come away with an understanding of the benefits of using immutable objects in your own distributed systems. You will learn a set of rules for identifying and exchanging immutable objects, and see a collection of useful theorems that emerges and ensures that the distributed systems we build are eventually consistent. Using patterns, you will find where the truth converges, see how changes are associative, rather than sequential, and come to feel comfortable understanding that there is no longer a single source of truth. Practical hands-on examples reinforce how to build software using the described patterns, techniques, and tools. By the end, you will possess the language and resources needed to analyze and construct distributed systems with confidence.

The assumptions of the past were sufficient for building single-user, single-computer systems. But as we expand to multiple devices, shared experiences, and cloud computing, they work against us. It is time for a new set of assumptions. Start with immutable objects, and build better distributed systems.

What You Will Learn

• Evaluate a distributed system from the perspective of immutable objects
• Recognize the problems in existing designs, and make small modifications to correct them
• Start a new system from scratch, applying patterns
• Apply the principles of immutable architecture to your tools, including SQL databases, message queues, and the network protocols that you already use
• Discover new tools that natively apply these principles

Who This Book Is For
Software architects and senior developers. It contains examples in SQL and languages such as JavaScript and C#. Past experience with distributed computing, data modeling, or business analysis is helpful.

本書教導讀者如何從不可變物件的角度評估分散式系統。您將了解現有設計中的問題，知道如何進行小的修改以解決這些問題，並學習將不可變架構的原則應用於您的工具中。

大多數軟體元件關注物件的狀態。它們將關聯式資料庫中的一行的當前狀態存儲起來。它們追蹤狀態隨時間的變化，並做出幾個基本假設：每個物件都有一個最新版本，物件的狀態按順序變化，並且存在一個記錄系統。

在構建分散式系統時，這是一個挑戰。無論是處理自治微服務還是斷開連接的移動應用程式，我們嘗試解決的許多問題都歸結為在孤立的元件之間同步不斷變化的狀態。如果物件無法更改，構建分散式系統將變得更加容易。

閱讀完《不可變架構的藝術》後，您將了解在自己的分散式系統中使用不可變物件的好處。您將學習一套識別和交換不可變物件的規則，並看到一系列有用的定理，確保我們構建的分散式系統最終是一致的。通過模式，您將找到真理的匯聚點，看到變化是關聯而不是順序的，並且開始感到舒適，了解不再有單一的真理來源。實際的實例將強化如何使用所描述的模式、技術和工具來構建軟體。最終，您將具備分析和構建分散式系統的語言和資源，並充滿信心。

過去的假設足以構建單用戶、單電腦系統。但隨著我們擴展到多個設備、共享體驗和雲端運算，這些假設反而阻礙了我們。是時候建立一套新的假設了。從不可變物件開始，構建更好的分散式系統。

本書的學習內容包括：

- 從不可變物件的角度評估分散式系統
- 辨識現有設計中的問題，並進行小的修改以修正它們
- 從頭開始建立新系統，應用模式
- 將不可變架構的原則應用於您已經使用的 SQL 資料庫、訊息佇列和網路協定等工具
- 發現原生應用這些原則的新工具

本書適合軟體架構師和高級開發人員閱讀。其中包含 SQL 和 JavaScript、C# 等語言的範例。具備分散式運算、資料建模或業務分析的經驗將有所幫助。

Michael L. Perry has built upon the works of mathematicians such as Bertrand Meyer, Leslie Lamport, and Donald Knuth to develop a mathematical system for software development. He has captured this system in a set of open source projects. Michael often presents on math and software at events and online. You can find out more at qedcode.com.

Michael L. Perry 建立在數學家 Bertrand Meyer、Leslie Lamport 和 Donald Knuth 的工作基礎上，開發了一個用於軟體開發的數學系統。他將這個系統應用於一系列的開源專案中。Michael 經常在活動和線上演講中介紹數學和軟體相關的主題。您可以在 qedcode.com 網站上獲得更多相關資訊。