Tuesday, 21 July 2009

Will BitTorrent ever beat the Data Centre?

With the Pirate Bay and Kazaa deciding to go legit, the way we access music, films and software could be about to change. Peer to peer (P2P) transfers of files, legal or not, has boomed since Napster's break through in technology in 1999. The introduction of BitTorrent's in 2001, a file sharing protocol that allows millions of computers around the world to share files quickly, has made sharing files easy and fast. The technology works by taking the original file from a user, and when it is downloaded, splitting that file into many small chunks. When there are multiple users downloading (or providing) a file, BitTorrent allows people to access these little bits from different people, which minimises the amount of bandwidth traffic that the original 'seeder' has to use to share the original file. The protocol ensures that the rarest part of the file is provided first to ensure high availability. As a result, large files can be downloaded very quickly, significantly faster than a normal website download could be achieved with multiple downloaders.

The popularity of this method of data transfer has exploded and now, although there are conflicting reports of actual amounts, around 30-50% of all internet traffic is thought to be from BitTorrent up and downloads. IsoHunt has claimed that there are 1.7 petabytes (1,000,000 gigabytes) being shared by their sources. Although BitTorrent downloading is popular, it cannot guarantee a connection to the file you require.

When you download a song from iTunes, you are connecting to their server in a Data Centre directly. You have a guaranteed connection speed from the Data Centre via a fibre optic cable. The only limitation to the speed you receive that file is the Internet Service Providers (ISP) network and your own personal internet connection. Theoretically, you could connect to the Data Centre at 14 terabits per second via fibre, which would effectively produce instant downloads. The reality is that fibre transmitters limit the possible bandwidth of fibre and that PC's cannot connect directly to a public fibre connection. Additionally, most bandwidth gets limited by connection via copper cables when connecting to a computer as it is a vastly cheaper method of data transfer in a localised area.

When you download a file from a P2P or BitTorrent network, you are connecting to individual PC's in the majority of cases. You are limited not only by your own computer, bandwidth and ISP, but by the person's that you are connecting to. BitTorrent is considerably more efficient at using this method over P2P due to the fact that it downloads many small files from many different users which allows the for an increase in availability. The limit to this technology appears when connecting to another user. If you could guarantee the connection speed there would be less of an issue, but connecting to P2P networks requires reliance on other users having the file you want, and that they have their computers switched on so you can receive it. In a Data Centre environment, a file would always be available.

So will BitTorrents ever replace the Data Centre? The nature of the connection method and the process that allows a BitTorrent file to be downloaded requires many people to have the same file and an active internet connection. There is no guarantee that you can download a file and each file that is not downloaded would lose someone money. While BitTorrent may be great for the free and illegal file downloading, the lack of control would make it hard to charge for the downloads. Aside from this, the majority of Data Centres require servers for their raw computing power and storage capabilities. BitTorrent software cannot recreate this and even if it could, the running costs would be significantly higher and the synchronisation impossible to maintain.

Migration Solutions is a specialist computer room and data centre company offering independent advice on the design, build and operation of data centres and computer rooms. See our website at www.migrationsolutions.com

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