IROP Research Presentation A JXTA Performance Evaluation David A. Noblet Department of Computer Science University of New Hampshire

Rennes, France Population: 195,000 Capital of Brétagne Famous for… 2 Rennes, France Population: 195,000 Capital of Brétagne Famous for… Half-timbered houses Cobblestone roads Crêpes Home of… University of Rennes IRISA Lab

La vie quotidienne (Daily Life) 3 La vie quotidienne (Daily Life) Almost everything is similar Almost nothing is the same Some important differences: Stores close early Transportation is punctual What commercials? There are no change machines!

Work Hard. Break Hard. Work as a social environment Togetherness 4 Work Hard. Break Hard. Work as a social environment Togetherness Lunch “Café (Coffee)?” Busy evenings Late mornings

My Research IRISA Lab PARIS Team JuxMem Project 5 My Research IRISA Lab PARIS Team JuxMem Project Peer-to-peer data sharing service Enables groups of computers to dynamically organize into a virtual data storage unit Could potentially allow research organizations to easily share common data Performance concerns

Computer Networks Communication groups Network services 6 Computer Networks Communication groups Directed graph representation Network services Typical examples Websites Email Instant messaging

The Client-Server Model 7 The Client-Server Model Two different roles Client Server Traditional Web browser - Web server Email client - Email server Simple Problems Scalability Fault tolerance

The Peer-to-Peer Model 8 The Peer-to-Peer Model One role -- The Peer Both requests and provides service More recent Examples Music sharing Gnutella WinMX Advantages Scales well Not centrally dependent Problems Extra Complexity --> Overhead

JXTA (http://www.jxta.org) 9 JXTA (http://www.jxta.org) Provides Set of XML-based peer-to-peer protocols Application framework to use the protocols Solves common peer-to-peer problems Runs under Java (though there are others) Used by JuxMem Common perceptions Java is slow XML is bulky Peer-to-peer services = lots of overhead

10 Testing Performance JXTA = Peer-to-peer + XML + Java = Bad performance? Maybe It is a concern Performance metrics Bandwidth (speed) Latency (responsiveness) How to find out Test! Round Trip Time (RTT) acknowledgement message

11 Some Results (1 of 3)

12 Some Results (2 of 3)

13 Some Results (3 of 3)

Conclusions JXTA doesn’t perform too poorly It does introduce overhead 14 Conclusions JXTA doesn’t perform too poorly Can basically saturate a Fast-Ethernet (100 Mb/s) connection Would be good for things like large file transfers It does introduce overhead Not incredibly responsive Has trouble keeping up with Myrinet