The Saga Pattern 傳說模式

In enterprise applications, nearly every request is executed within a database transaction. 
在企業應用程式中，幾乎每個請求都在數據庫事務中執行。

Developers often use frameworks and libraries with declarative mechanisms to simplify transaction management.
開發人員通常使用具有聲明性機制的框架和庫來簡化交易管理。

The Spring framework, for example, uses a special annotation to arrange for method invocations to be automatically executed within a transaction. This annotation simplifies writing transactional business logic, making it easier to manage transactions in a monolithic application that accesses a single database.
Spring 框架，例如，使用特殊的註釋來安排方法調用在事務內自動執行。這個註釋簡化了撰寫事務業務邏輯，使得在訪問單個數據庫的單體應用程序中更容易管理事務。

However, while transaction management is relatively straightforward in a monolithic application accessing a single database, it becomes more complex in scenarios involving multiple databases and message brokers. 
然而，在單體應用程式中，訪問單一數據庫的交易管理相對簡單，但在涉及多個數據庫和消息代理的情況下，變得更加複雜。

For example, in a microservice architecture, business transactions span multiple services, each with its database. This complexity makes the traditional transaction approach impractical. Instead, microservices-based applications must adopt alternative mechanisms to manage transactions effectively.
例如，在微服務架構中，業務交易涵蓋多個服務，每個服務都有自己的數據庫。這種複雜性使得傳統的交易方法變得不切實際。相反，基於微服務的應用程序必須採用替代機制來有效管理交易。

In this post, we’ll learn why microservices-based applications require a more sophisticated approach to transaction management, such as using the Saga pattern. We’ll also understand the different approaches to implementing the Saga pattern in an application.
在這篇文章中，我們將了解為什麼基於微服務的應用程序需要更複雜的交易管理方法，例如使用 Saga 模式。我們還將了解在應用程序中實施 Saga 模式的不同方法。

The Need for Saga Pattern
對於傳說模式的需求