成方圆非常星发布:'Second Life': Don't worry, we can scale | Tech News on ZDNet

By Daniel Terdiman
Posted on ZDNet News: Jun 6, 2006 11:00:00 AM

The bet was certainly ambitious.After all, "WoW," as fans call it, currently has more than 6.5 millionusers. "Second Life" has 240,000 registered users. But whether LindenLab's virtual world can catch "WoW" isn't the most pressing questionabout the virtual world's future for some people familiar with itscomputer network.

Their concern is more about technology: Can the computer network of"Second Life," using an unusual configuration that dedicates eachserver to a sliver of virtual real estate, scale with growing demand?

"Second Life" currently runs on 2,579 servers that use the dual-coreOpteron chip produced by AMD. Each server is responsible for anindividual "sim," or 16 acres of virtual "Second Life" land. At peakusage that means that each server is handling about three users.

"Most (massively multiplayer online games) have hundreds tothousands of players per server machine," said Michael Sellers, whoruns Online Alchemy, a provider of artificial-intelligence tools foronline games. "Is there a way they can achieve (significant) elementsof scale? I haven't seen that."

There's little question that "Second Life" manages far fewer usersper server than other virtual worlds. Sony Online Entertainment's"EverQuest II," which has more than 250,000 users, runs on about 1,100dual-CPU, x86 (x86 is the processor architecture used by most AMD andIntel chips) servers spread across 37 clusters of 20 to 40 servers.Each of those handles around 116 users at peak usage, according tofigures provided by SOE.

Big bucks needed?
These wildly different figures have someobservers scratching their heads and wondering if Linden Lab is goingto have to spend big to keep the "Second Life" network growing.

"My understanding of (Linden Lab's) back-end requirements are thatthey're absurd and unsustainable," said Daniel James, CEO of ThreeRings, publisher of the online game "Puzzle Pirates." "They have (about) as many peak simultaneous players as we do, and we're doing it on four CPUs."

But Linden Lab executives have a message for worrywarts: Relax.

"It works just like Google, where each (server) is a single, cheap(server) that basically operates and is automatically deployed by oursystems and simulates the systems," said Linden Lab CEO Philip Rosedale.

Rosedale argued that his company's architecture mirrors that of theInternet itself, which he characterized as millions of servers runningin a decentralized system.

Linden Lab is constantly adding new servers as its user base growsand as users demand new "land." And since "sims" generate a minimum of$200 in monthly land-use fees, Rosedale contended that the large numberof servers pay for themselves.

"Can it scale indefinitely?Absolutely," Rosedale said. "It can scale to infinity. The underlyingarchitecture of the Internet and of 'Second Life' is perfectlyscalable."

He said that most massively multiplayer online games, like "World ofWarcraft" and "EverQuest II," are designed around a central databasethat does the heavy lifting of managing as many concurrent users perserver as possible.

By comparison, the "Second Life" environment is spread across itsmany servers, which Rosedale said are in a "tiled network" whosedemands on the central database are akin to that of e-mail.

"We just throw new machines at it all the time," he said. "So it is we who have the scalable architecture."

While there may be questions in the online-games community aboutLinden Lab's server strategy, the model has proven successful for othercompanies.

"It works pretty well for Google and Yahoo," said Gordon Haff, asenior analyst at Illuminata who was not familiar with Linden Lab'sarchitecture.

'Radically different' approach
"It sounds like an approachwhere they can segment the tasks by segmenting the data structure,"added Dan Kusnetzky, formerly the vice president of systems softwareresearch for IDC who is now executive vice president of marketing atOpen-Xchange. "And that sounds like a good tradeoff."

Kusnetzky agreed with Haff that other companies have succeeded with Linden Lab's model.

"You can get some unbelievable scalability stories if you can thinkthrough the stories and build a lightweight architecture," he said."That's how Google and Yahoo do it."

In any case, some say "Second Life" is already bigger than they ever expected.

"They're succeeding because of their radically different approach tothis business," said Edward Castronova, an expert on virtual worlds andan associate professor of telecommunications at Indiana University.

Indeed, while most online games make money by charging every user amonthly fee, "Second Life" is free to play unless a user wants to ownland. Linden Lab makes its money off of land-use fees, the sale of itsvirtual currency and monthly fees paid by land owners.

Rosedale said Linden Lab isn't yet profitable, but soon will be.

He also acknowledged that "Second Life" has a difficult userinterface that is an impediment to massive adoption and that Linden Labhas to work on that. He pointed to potential future plans to let userscreate their own "skins" for the interface, a step that would givecontrol over the interface, like all other "Second Life" content, tousers.

Castronova, who said he does have some worries about the "SecondLife" business model, said it's worth sticking around to find out whathappens.

"Regarding (their) business model, I have the anxiety of someone whowent out to explore a river," he said, "and I'm already 200 milesfurther than I ever thought I would get and there's still more river.Scary, but I have to keep going."