By Steven Levy
A central cooling plant in Google’s Douglas County, Georgia, data center.
Photo: Google/Connie Zhou
If you’re looking for the beating heart of the digital age — a physical location where the scope, grandeur, and geekiness of the kingdom of bits become manifest—you could do a lot worse than Lenoir, North Carolina. This rural city of 18,000 was once rife with furniture factories. Now it’s the home of a Google data center.
Engineering prowess famously catapulted the 14-year-old search giant into its place as one of the world’s most successful, influential, and frighteningly powerful companies. Its constantly refined search algorithm changed the way we all access and even think about information. Its equally complex ad-auction platform is a perpetual money-minting machine. But other, less well-known engineering and strategic breakthroughs are arguably just as crucial to Google’s success: its ability to build, organize, and operate a huge network of servers and fiber-optic cables with an efficiency and speed that rocks physics on its heels. Google has spread its infrastructure across a global archipelago of massive buildings—a dozen or so information palaces in locales as diverse as Council Bluffs, Iowa; St. Ghislain, Belgium; and soon Hong Kong and Singapore—where an unspecified but huge number of machines process and deliver the continuing chronicle of human experience.
This is what makes Google Google: its physical network, its thousands of fiber miles, and those many thousands of servers that, in aggregate, add up to the mother of all clouds. This multibillion-dollar infrastructure allows the company to index 20 billion web pages a day. To handle more than 3 billion daily search queries. To conduct millions of ad auctions in real time. To offer free email storage to 425 million Gmail users. To zip millions of YouTube videos to users every day. To deliver search results before the user has finished typing the query. In the near future, when Google releases the wearable computing platform called Glass, this infrastructure will power its visual search results.
The problem for would-be bards attempting to sing of these data centers has been that, because Google sees its network as the ultimate competitive advantage, only critical employees have been permitted even a peek inside, a prohibition that has most certainly included bards. Until now.
A server room in Council Bluffs, Iowa.
Photo: Google/Connie Zhou
Here I am, in a huge white building in Lenoir, standing near a reinforced door with a party of Googlers, ready to become that rarest of species: an outsider who has been inside one of the company’s data centers and seen the legendary server floor, referred to simply as “the floor.” My visit is the latest evidence that Google is relaxing its black-box policy. My hosts include Joe Kava, who’s in charge of building and maintaining Google’s data centers, and his colleague Vitaly Gudanets, who populates the facilities with computers and makes sure they run smoothly.
A sign outside the floor dictates that no one can enter without hearing protection, either salmon-colored earplugs that dispensers spit out like trail mix or panda-bear earmuffs like the ones worn by airline ground crews. (The noise is a high-pitched thrum from fans that control airflow.) We grab the plugs. Kava holds his hand up to a security scanner and opens the heavy door. Then we slip into a thunderdome of data …
Urs Hölzle had never stepped into a data center before he was hired by Sergey Brin and Larry Page. A hirsute, soft-spoken Swiss, Hölzle was on leave as a computer science professor at UC Santa Barbara in February 1999 when his new employers took him to the Exodus server facility in Santa Clara. Exodus was a colocation site, or colo, where multiple companies rent floor space. Google’s “cage” sat next to servers from eBay and other blue-chip Internet companies. But the search company’s array was the most densely packed and chaotic. Brin and Page were looking to upgrade the system, which often took a full 3.5 seconds to deliver search results and tended to crash on Mondays. They brought Hölzle on to help drive the effort.
It wouldn’t be easy. Exodus was “a huge mess,” Hölzle later recalled. And the cramped hodgepodge would soon be strained even more. Google was not only processing millions of queries every week but also stepping up the frequency with which it indexed the web, gathering every bit of online information and putting it into a searchable format. AdWords—the service that invited advertisers to bid for placement alongside search results relevant to their wares—involved computation-heavy processes that were just as demanding as search. Page had also become obsessed with speed, with delivering search results so quickly that it gave the illusion of mind reading, a trick that required even more servers and connections. And the faster Google delivered results, the more popular it became, creating an even greater burden. Meanwhile, the company was adding other applications, including a mail service that would require instant access to many petabytes of storage. Worse yet, the tech downturn that left many data centers underpopulated in the late ’90s was ending, and Google’s future leasing deals would become much more costly.
For Google to succeed, it would have to build and operate its own data centers—and figure out how to do it more cheaply and efficiently than anyone had before. The mission was codenamed Willpower. Its first built-from-scratch data center was in The Dalles, a city in Oregon near the Columbia River.
Hölzle and his team designed the $600 million facility in light of a radical insight: Server rooms did not have to be kept so cold. The machines throw off prodigious amounts of heat. Traditionally, data centers cool them off with giant computer room air conditioners, or CRACs, typically jammed under raised floors and cranked up to arctic levels. That requires massive amounts of energy; data centers consume up to 1.5 percent of all the electricity in the world.
Google realized that the so-called cold aisle in front of the machines could be kept at a relatively balmy 80 degrees or so—workers could wear shorts and T-shirts instead of the standard sweaters. And the “hot aisle,” a tightly enclosed space where the heat pours from the rear of the servers, could be allowed to hit around 120 degrees. That heat could be absorbed by coils filled with water, which would then be pumped out of the building and cooled before being circulated back inside. Add that to the long list of Google’s accomplishments: The company broke its CRAC habit.
Google also figured out money-saving ways to cool that water. Many data centers relied on energy-gobbling chillers, but Google’s big data centers usually employ giant towers where the hot water trickles down through the equivalent of vast radiators, some of it evaporating and the remainder attaining room temperature or lower by the time it reaches the bottom. In its Belgium facility, Google uses recycled industrial canal water for the cooling; in Finland it uses seawater.
The company’s analysis of electrical flow unearthed another source of waste: the bulky uninterrupted-power-supply systems that protected servers from power disruptions in most data centers. Not only did they leak electricity, they also required their own cooling systems. But because Google designed the racks on which it placed its machines, it could make space for backup batteries next to each server, doing away with the big UPS units altogether. According to Joe Kava, that scheme reduced electricity loss by about 15 percent.
All of these innovations helped Google achieve unprecedented energy savings. The standard measurement of data center efficiency is called power usage effectiveness, or PUE. A perfect number is 1.0, meaning all the power drawn by the facility is put to use. Experts considered 2.0—indicating half the power is wasted—to be a reasonable number for a data center. Google was getting an unprecedented 1.2.
For years Google didn’t share what it was up to. “Our core advantage really was a massive computer network, more massive than probably anyone else’s in the world,” says Jim Reese, who helped set up the company’s servers. “We realized that it might not be in our best interest to let our competitors know.”
But stealth had its drawbacks. Google was on record as being an exemplar of green practices. In 2007 the company committed formally to carbon neutrality, meaning that every molecule of carbon produced by its activities—from operating its cooling units to running its diesel generators—had to be canceled by offsets. Maintaining secrecy about energy savings undercut that ideal: If competitors knew how much energy Google was saving, they’d try to match those results, and that could make a real environmental impact. Also, the stonewalling, particularly regarding The Dalles facility, was becoming almost comical. Google’s ownership had become a matter of public record, but the company still refused to acknowledge it.
In 2009, at an event dubbed the Efficient Data Center Summit, Google announced its latest PUE results and hinted at some of its techniques. It marked a turning point for the industry, and now companies like Facebook and Yahoo report similar PUEs.
Make no mistake, though: The green that motivates Google involves presidential portraiture. “Of course we love to save energy,” Hölzle says. “But take something like Gmail. We would lose a fair amount of money on Gmail if we did our data centers and servers the conventional way. Because of our efficiency, we can make the cost small enough that we can give it away for free.”
Google’s breakthroughs extend well beyond energy. Indeed, while Google is still thought of as an Internet company, it has also grown into one of the world’s largest hardware manufacturers, thanks to the fact that it builds much of its own equipment. In 1999, Hölzle bought parts for 2,000 stripped-down “breadboards” from “three guys who had an electronics shop.” By going homebrew and eliminating unneeded components, Google built a batch of servers for about $1,500 apiece, instead of the then-standard $5,000. Hölzle, Page, and a third engineer designed the rigs themselves. “It wasn’t really ‘designed,’” Hölzle says, gesturing with air quotes.
More than a dozen generations of Google servers later, the company now takes a much more sophisticated approach. Google knows exactly what it needs inside its rigorously controlled data centers—speed, power, and good connections—and saves money by not buying unnecessary extras. (No graphics cards, for instance, since these machines never power a screen. And no enclosures, because the motherboards go straight into the racks.) The same principle applies to its networking equipment, some of which Google began building a few years ago.
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