December 7, 2005

A cure for the 'Slashdot effect'

Author: Tina Gasperson

A little brain power, some readily available open source tools, and two IT services providers out to prove they can solve the "Slashdot effect": Put them together, and you've got Mirrordot, a site that automatically mirrors any Slashdot-linked pages.

The "Slashdot effect" is what happened when a huge number of people click on a link embedded in a Slashdot article. (Slashdot is a sister site of NewsForge.) Many times the servers at the site linked to get so inundated with connection requests that they become impossible to reach.

Mirrordot works by picking up the Slashdot news feed, creating a blog-like page with all the same articles and links. The only difference is that on Mirrordot when you click on a link, instead of going to, for example, you'll end up at the snapshot picked up by Mirrordot at the time the original Slashdot story was posted.

Jay Jacobson says that he and his partner Erik Stephens aren't looking to get rich and famous. They don't charge for the mirroring service and pay for the large bandwidth requirements out of their own pockets. They've even been approached by "a couple of other sites to mirror them," Jacobson says, "but we haven't really done that. Our initial intention was to make a statement and prove a point, not to build a business." In fact, Jacobson and Stephens already own a business, called EdgeOS, that provides managed vulnerability assessment services.

Jacobson and Stephens are open source software advocates, and it shows in the tools they used to create Mirrordot. "It's all open source," Jacobson says. "We run on two dedicated Web servers, both of them are pretty low hardware stacks, Pentium III 700MHz machines." Mirrordot runs on Debian Linux, "plain" Apache that is pared down to a very low memory footprint and configured to be able to "fire up many processes very quickly," and wget, a network utility to retrieve files from the World Wide Web. "It's just all standard configuration things," Jacobson says. "You have the box spec tuned and designed for the function that you're trying to accomplish.

"We've never been brought down or had our servers slow down, and we've mirrored probably greater than 90% of the articles that have appeared."

Jacobson emphasizes that what he and Stephens have done is simple. "What we've built is not rocket science or a ton of new technology," he says. So why haven't others borrowed this system or built their own, namely the Web sites most likely to be hampered by the Slashdot effect? "We started out thinking, 'why hasn't anybody done anything about this? There must be some difficulty people are running into.' So we said, 'Let's start doing it ourselves and see what hurdle we run into.'" Everything went smoothly. Jacobson's conclusion? "Most people who call themselves geeks are not."

But, he adds, one potential challenge small sites may face is lack of bandwidth. "Our bandwidth use is very spiky," he says. "Sometimes it saturates a 100MB connection, and not everybody has that. It's not the kind of project somebody could stick on their home cable modem connection."

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