An in-depth measurement and analysis of popular private tracker systems in China

In recent years, a novel BitTorrent (BT) technology, Private Tracker (PT), has received extensive attentions in academia. Due to its huge amount of traffic volumes and population, it is essential to understand the characteristics for system management. In this paper, by using the data crawled from a number of well-known PT sites in China, we present an in-depth measurement and analysis on the PT system, in terms of resources characteristics and user behavior characteristics. Our analysis on the activity and age distribution of torrents reveals that the sequence of torrent activities follows a power-law distribution and the sequence of torrent ages follows a linear distribution. By investigating the characteristics of the core users and the resources in different PT sites, two observations have been made. Firstly, every PT site has a number of users with stable levels who contribute to the survivability and popularity of the site. Secondly, a large amount of redundancy exists among the distributed resources and many popular resources are duplicated among these sites, which leads to the quick spread of pirate resources. Based on the measurement results, we analyze the drawbacks of PT mechanisms and propose useful suggestions to promote the healthy development and performance of PT.