Service Availability: Principles and Practice (Hardcover)

Our society increasingly depends on computer-based systems; the number of applications deployed has increased dramatically in recent years and this trend is accelerating. Many of these applications are expected to provide their services continuously. The Service Availability Forum has recognized this need and developed a set of specifications to help software designers and developers to focus on the value added function of applications, leaving the availability management functions for the middleware.

A practical and informative reference for the Service Availability Forum specifications, this book gives a cohesive explanation of the founding principles, motivation behind the design of the specifications, and the solutions, usage scenarios and limitations that a final system may have. Avoiding complex mathematical explanations, the book takes a pragmatic approach by discussing issues that are as close as possible to the daily software design/development by practitioners, and yet at a level that still takes in the overall picture. As a result, practitioners will be able to use the specifications as intended.

• Takes a practical approach, giving guidance on the use of the specifications to explain the architecture, redundancy models and dependencies of the Service Availability (SA) Forum services
• Explains how service availability provides fault tolerance at the service level
• Clarifies how the SA Forum solution is supported by open source implementations of the middleware
• Includes fragments of code, simple example and use cases to give readers a practical understanding of the topic
• Provides a stepping stone for applications and system designers, developers and advanced students to help them understand and use the specifications

我們的社會越來越依賴基於電腦的系統；近年來部署的應用程式數量急劇增加，並且這個趨勢正在加速。許多這些應用程式被期望能夠持續提供服務。服務可用性論壇已經認識到這個需求，並制定了一套規範，以幫助軟體設計師和開發人員專注於應用程式的增值功能，將可用性管理功能留給中介軟體。

作為服務可用性論壇規範的實用且資訊豐富的參考資料，本書提供了對創始原則、規範設計背後的動機以及最終系統可能具有的解決方案、使用情境和限制的連貫解釋。本書避免了複雜的數學解釋，採用務實的方法，討論與從業人員日常軟體設計/開發最相關的問題，同時又能夠全局性地考慮。因此，從業人員將能夠按照規範的意圖使用它們。

本書採用實用方法，提供了使用規範的指導，以解釋服務可用性（SA）論壇服務的架構、冗餘模型和相依性。解釋了服務可用性如何在服務層面上提供容錯能力。澄清了SA論壇解決方案如何由中介軟體的開源實現支持。包含了程式碼片段、簡單範例和使用案例，以使讀者對主題有實際的理解。為應用程式和系統設計師、開發人員和高級學生提供了一個起點，幫助他們理解和使用這些規範。