O'Reilly Network Weekly
Open Source Roundtable
Sponsored by IBM developerWorks

Free Riding on Gnutella
10/09/2000

Does Gnutella suffer from a tragedy of the digital commons? Eytan Adar and Bernardo A. Huberman of Xerox's Palo Alto Research Center (PARC) analyzed user traffic on Gnutella and discovered "a significant amount of free riding in the system." Nearly half the files shared came from just 1 percent of hosts -- which suggests something closer to a traditional client-server model, rather than a peer-to-peer system. It also suggests that this particular application is not as immune to legal repercussions as users might boast. When millions of users are trading copyrighted materials, it's quixotic to imagine bringing the community to court. But could it be feasible to target the high-volume servers?

Their paper is hosted at First Monday, a peer-reviewed online journal.

We talked with Eytan and asked him to explain what they were looking for, what they found, and how Gnutella might be improved to overcome the shortcomings they've identified.

Listen to this discussion (12:11 mins, 2.8 MB):

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Eytan Adar Researcher, Xerox PARC Digital Freedom Network "While there's a utopian view of Gnutella and file sharing as this great thing, we realize that it's possible that the social dilemmas that affect individuals in the real world mught affect people in the digital world. Where there's a high cost and a low reward, people are less likely to conform to some social contract where there's nothing for them to gain and only things to lose. We decided to look at this in terms of Gnutella, to see how many people were actually contributing to the system. Basically what we discovered is that there was a significant amount of free riding in the system. Over 70 percent of people shared no files, which is fairly significant."

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