This paper presents a detailed measurement study of the BitTorrent file-sharing system in combination with Suprnova, focusing on four key aspects: availability, integrity, flashcrowd handling, and download performance. BitTorrent is a P2P file-sharing protocol that relies on global components such as web sites for file search and employs a moderator system to ensure data integrity. The study shows that BitTorrent has become one of the most popular P2P networks, with 53% of all P2P traffic in June 2004. The research involved collecting data over 8 months from more than 2,000 global components and tracking 90,155 peers for a popular file. The study also measured the bandwidth of 54,845 peers downloading over 100 newly injected files. The paper highlights the importance of availability, integrity, and handling of flashcrowds in P2P systems. It finds that the availability of global components significantly affects the performance of the system. The study also shows that the integrity of content is maintained through a moderator system, which effectively filters out fake files. However, the system is vulnerable to denial-of-service attacks and has a high dependency on global components. The study also examines the flashcrowd effect, where a sudden surge in demand for a single file can overwhelm the system. The results show that the system can handle large flashcrowds efficiently. The download performance of the system is also analyzed, showing that the average download speed is relatively low, with 90% of peers having a download speed below 520 kbps. The paper concludes that BitTorrent/Suprnova is a successful P2P system that has the right mechanisms to attract a large user community. However, the system's reliance on global components and the need for decentralization remain challenges for future research. The study also highlights the importance of incentives to encourage seeding, as well as the need for further research into content lifetime and the long-term behavior of P2P systems.This paper presents a detailed measurement study of the BitTorrent file-sharing system in combination with Suprnova, focusing on four key aspects: availability, integrity, flashcrowd handling, and download performance. BitTorrent is a P2P file-sharing protocol that relies on global components such as web sites for file search and employs a moderator system to ensure data integrity. The study shows that BitTorrent has become one of the most popular P2P networks, with 53% of all P2P traffic in June 2004. The research involved collecting data over 8 months from more than 2,000 global components and tracking 90,155 peers for a popular file. The study also measured the bandwidth of 54,845 peers downloading over 100 newly injected files. The paper highlights the importance of availability, integrity, and handling of flashcrowds in P2P systems. It finds that the availability of global components significantly affects the performance of the system. The study also shows that the integrity of content is maintained through a moderator system, which effectively filters out fake files. However, the system is vulnerable to denial-of-service attacks and has a high dependency on global components. The study also examines the flashcrowd effect, where a sudden surge in demand for a single file can overwhelm the system. The results show that the system can handle large flashcrowds efficiently. The download performance of the system is also analyzed, showing that the average download speed is relatively low, with 90% of peers having a download speed below 520 kbps. The paper concludes that BitTorrent/Suprnova is a successful P2P system that has the right mechanisms to attract a large user community. However, the system's reliance on global components and the need for decentralization remain challenges for future research. The study also highlights the importance of incentives to encourage seeding, as well as the need for further research into content lifetime and the long-term behavior of P2P systems.