[Show abstract][Hide abstract] ABSTRACT: Web server scalability can be greatly enhanced via hybrid data dissemination methods that use both unicast and multicast. Hybrid data dissemination is particularly promising due to the development of effective end-to-end multicast methods and tools. Hybrid data dissemination critically relies on document selection which determines the data transfer method that is most appropriate for each data item. In this paper, we study document selection with a special focus on actual end-point implementations and Internet network conditions. We individuate special challenges such as scalable and robust popularity estimation, appropriate classification of hot and cold documents, and unpopular large documents. We propose solutions to these problems, integrate them in MBDD (middleware support multicast-based data dissemination) and evaluate them on PlanetLab with collected traces. Results show that the multicast server can effectively adapt to dynamic environments and is substantially more scalable than traditional Web servers. Our work is a significant contribution to building practical hybrid data dissemination services.
[Show abstract][Hide abstract] ABSTRACT: In this paper, we argue that pervasive applications need to be aware of and adaptive to network conditions. We begin with an overview of three software projects in which we are currently involved, and highlight network awareness and application adaptability as a common thread among them. We argue that these features stem from the fundamental architectural principles of the Internet. We generalize our experience and elaborate on the principles for developing network awareness and adaptable applications.
Full-text · Article · Oct 2006 · Information Systems and e-Business Management
[Show abstract][Hide abstract] ABSTRACT: data in the Internet. Middleware support for multicast-based data dissemination (MSMDD) aims to integrate state-of-the-art data management methods and multicast communication techniques and provide a scalable multicast-based data management layer to applications. By using multicast in MSMDD, the server can disseminate hot documents effectively. To evaluate multicast performance, previous work often utilizes network-level metrics. In this paper, we employ application level criteria to analyze the multicast push performance in MSMDD. When packets are not lost on links, our result shows that the applicationperceived (or client-perceived) performance is independent of the delay from the server to clients; the multicast rate is a major factor for the performance; an end-to-end multicast system achieves almost the same application-perceived performance as IP multicast under the same multicast rates. However, IP multicast can tolerate much more packet losses than the end-to-end multicast system.
[Show abstract][Hide abstract] ABSTRACT: IntroductionA major problem on the Internet is the scalable disseminationof information. This problem is particularly acuteexactly at the time when the scalability of data delivery ismost important, e.g., election results on the night of the2000 United States presidential election, and news during9/11/2001. The current unicast pull framework simply doesnot scale up to these types of workloads. One proposed solutionto this scalability problem is to use multicast communication....