近年來，隨著Peer-to-Peer (P2P)技術的快速發展和普及，P2P的應用已不限於檔案分享，在影音串流上的應用也越來越普遍。BitTorrent (BT)是近年來被認為是一種有效率的P2P機制，雖然本身並不適合直接應用在影音串流，但是已有眾多研究者提出讓BT支援串流應用的技術。
BT協定中唯一的中央式元件是Tracker伺服器，負責協調用戶之間的連線和傳輸，在重視real-time的串流應用中，Tracker伺服器的品質相當重要。因此，在此篇論文中，我們配合Service AvailabilityTM Forum (SA Forum)所訂定的應用介面規範 (Application Interface Specification ; AIS)來建立一個高可用度之BT Tracker，具備資料備援和還原的功能。
我們在250~2000個用戶和檔案的情況下，測量用戶端回應時間和備援時間，對高可用度BT Tracker的效能做出結論。

Recently, as the rapid development and popularization of peer-to-peer (P2P) technology, the P2P technology is not only applied to file-sharing, but also to video streaming. BitTorrent (BT) has been one of the most effective mechanisms for P2P file-sharing. Although BT was not created for distribution time-sensitive content, such as video streaming, a lot of research on making BT to support streaming multimedia has been published.

The only one centralized component of BT is tracker. The functionality of tracker is to coordinate peers and to help peers to find each other. Consequently, the service availability of tracker is significant in video streaming. In this thesis, according to AIS defined by SA Forum, we design a high availability BT tracker that supports backup and restoration.

We measure the response time of clients and the backup/restoration overhead on the condition of 250~2000 peers. According to the results, we make some conclusions for the performance of HA BT tracker.

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