網路服務(Web Services)是一項新興的技術，其分散式且可組裝的特性被許多企業認為是未來建立分散式系統的重要元件，鬆偶合式(loosely coupling)的架構、跨越異質環境或平台、防火牆的穿透性、最大的重覆使用性都是其專屬特色，這技術可應用在各種領域，包括電子商務、系統整合…等，因此透過網路服務技術在企業的各系統之間做整合，可以使得企業專注在關鍵工作上。
　　由於網路服務技術越來越受到各界的歡迎，因此它的穩定度與可靠度更形重要，本研究設計與實作完成的網路服務容錯機制模組，可以提供網路服務於容錯機制上的參考方向，並以兩種不同的策略實作容錯機制物件。
　　在容錯能力方面，不考慮拜占庭錯誤(Byzantine Faults)的情況下，除了程序、主機故障外，還可以解決網路分割所造成的錯誤情況，效能評估方面，以Quorum-base Protocol對於系統回應時間上有較好的表現，但是動態投票演算法在容錯能力上卻比Quorum-base Protocols來的好。
　　本研究建構一個應用於網路服務的容錯機制，透過系統實作與評估，經由實驗數據分析顯示，證明本研究所設計的機制，在只增加原系統些微的負荷便能夠使服務提供者架構起具有容錯能力的網路服務，使得在程序、主機故障或是網路分割發生時，可以有效的調派其他網路服務副本來遞補錯誤的發生。

　Web Services are a new developing technology, and the characteristic that can be assembled and distributed is thought it is an important component setting up the distributed system in the future by a lot of enterprises. The key advantage of using Web Services is the ability to create applications on the fly through the use of loosely coupled, reusable software components. Businesses can be released from the burden of complex, low, and expensive software integration and focus instead on the value of their offerings and mission critical tasks.
　Web Services are becoming popular in Web applications, so its stability and reliability is more important. The fault tolerant mechanism of Web Services designed in this research can offer Web Services in the fault tolerant direction.
　In fault tolerant ability, not considering it under the situation of Byzantine Faults, besides trouble of the host computer, can also solve the network partition problem. In efficiency, Quorum-base Protocol does well in response time, but Dynamic Voting algorithm is better than Quorum-base Protocols on fault tolerant ability.
　This research sets up a fault tolerant mechanism applied to Web Services, show via the experimental data, and prove the mechanism designed in this research only increases the load slightly of the original system. This mechanism makes a service provider set up Web Services with fault tolerant ability, when the trouble of host computer or network partition problem, can assign other Web Services copy effectively.

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