PARSEC APPLICATIONS

RumorSim

RumorSim is the simulation model of Rumor replicated file system, a system that can be used to keep multiple copies of files consistent. Rumor is especially useful for keeping replicated files on mobile computers. Maintaining multiple replicas of each file allows for higher availability. In particular, allowing mobile computers to store file replicas ensures that users will be able to access important data while disconnected, while still maintaining a single environment shared with workstation machines when connected. To further improve availability, Rumor uses an optimistic replication strategy. Optimistic replication permits any accessible replica to be updated, thus allowing disconnected portable computers to not only read, but also write, their local file replicas.

More Information

• Rumor Web Site

Simulation and Analysis of the Cache Group Management Protocol

Overview

The extraordinary success of the World Wide Web has revolutionized today's communication technology, yet has also produced an important problem affecting all Internet users: network congestion due to web traffic. This problem is particularly severe in the case of Internet "hot spots" (extremely popular web sites that can attract millions of requests a day). Although the extreme popularity of these hot spots is usually transient, typically lasting a few hours, they nevertheless pose an important problem to the overall performance and viability of the Internet as these "hot spots" become increasingly more common.

One promising potential solution is "Adaptive Web Caching," which is being proposed by the Internet Research Lab at UCLA. This solution suggests building a highly scalable, self-configuring, dynamically adjusting, demand-driven infrastructure of Web caches in the Internet that will reduce both network load and user response time. Adaptive Web Caching consists of several AWC cache servers that are strategically placed in the Internet. These cache servers communicate with each other via two new integrated protocols that comprise AWC: the Cache Group Management Protocol (CGMP) and the Cache Resolution Protocol (CRP). These two protocols in tandem are designed to diffuse popular web data away from the origin server towards the clients, thus eliminating the server bottleneck and placing the data closer to the demand for it. In order to evaluate the effectiveness of AWC, however, the protocol must be simulated. Our initial effort in this area is to first simulate the CGMP in a realistic environment, then later add the CRP to simulate the entire AWC system. Thus, this paper discusses our simulation of CGMP. In particular, we first discuss AWC and CGMP in more detail, then describe our system design for the simulation, next discuss our methodology for evaluating the effectiveness of CGMP, and finally present our simulation results and analysis.

Machines

More Information

• Download this model at CGMP Home Page
• Contact Khoi Nguyen at khoi@cs.ucla.edu or Nathan Sturtevant at nathanst@cs.ucla.edu.
• Why We Chose Parsec over NS

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• RSVP Simulator Home Page
• Download this model