A large number of. But the glitch illustrates not just the troubles with cloud computing, but also the gradual progress in making the concept palatable.
Cloud computing, in which software runs not on PCs or company servers but instead on computers on the Internet, requires something of a leap of faith both technologically and culturally. Those making the move must get accustomed to a reliance on somebody else's computing infrastructure, and that can be scary.
What's gradually emerging, though, are guarantees and practical tools that likely will help ease the transition.
Google, for example, offers a service level agreement (SLA) promising that Gmail, the online e-mail component of its overall Google Apps service, will be available 99.9 percent of the time, with service credits extended to paying customers if Gmail dips below that level.
And SLAs are coming to the rest of Google Apps.
"We don't have an SLA yet for Google Calendar or Google Docs, but it's something we're moving quickly toward," said Rishi Chandra, product manager for Google Apps. Google wants "to get the same level of reliability for all of Apps," he said.
Google is a major proponent of cloud computing, with advocacy work down to the level of, and of its own. The trend has the potential to seriously redistribute wealth within the computing industry.
There are two broad categories of cloud computing. First are online applications such as Google's Apps, Adobe Buzzword for word processing, and for managing customer relations. Second are general-purpose foundations such as , , and on which customers can run their own applications., ,
Taking the plunge into the cloud
Service level agreements are the kind of contractual guarantees that appeal to CIOs making cost-benefit analyses. But there's a gut-level factor at play here, too.
Psychologically, it's well-known in risk analysis circles that people feel more comfortable with risk if they feel in control. Thus people are often more comfortable driving a car on a congested freeway compared with being flown somewhere in a commercial jet, regardless of the relative safety of the two forms of transport.
So naturally there's some fear with cloud computing: it means you can't reboot your laptop or check for blinking red lights on the data center servers.
Companies are working to address this side of the equation, too. One prime example is the Trust.salesforce.com site, which shows the response time for a Salesforce.com server transaction. It also details when problems happened, what they affected, and what caused them.
"We've found working with our customers they want transparency. They want to know exactly what's going on all the time," said Bruce Francis, Salesforce.com's vice president of corporate strategy. "If there's an issue, they're not furious; they just want to know exactly what's going on."
Amazon.com, too, offers a basic status report dashboard for Amazon Web Services. "A service dashboard is something our developers asked us for, and we made the service available to them as soon as possible," said spokeswoman Kay Kinton.
"Own your own risk"
And some others are even trying to make a business out of reducing the uncertainties of cloud computing. One is open-source monitoring and management software company . The company is working hard to extend its monitoring service to other sites, too, including Google App Engine, said Stacey Schneider, senior director of marketing.
"You can't get away from owning your own risk. This is slowing the adoption of the cloud," she said.
Google is trying to communicate better with users and customers, Chandra said, though he stopped short of revealing what the uptime is for Google Docs or detailing why exactly it had problems earlier this week.
"With the docs outage, we posted immediately in the administrative console that there was an issue. We posted to the help center and the phone line system that we were working quickly to resolve it," Chandra said.
Asked whether Google plans its own status dashboard, Chandra wouldn't share details but promised better help for users. "We're trying to find even more ways to be more transparent about reliability," he said.
Risks of non-cloud computing, too
Much ado can and should be made of the risks of cloud computing, but it should be noted that even the much more mature business of computing without a cloud has its risks. Downtime, either with ailing or stolen PCs or with overtaxed or faulty servers, is a serious problem there, too.
Those with high-end services boast of "five nines" of reliability, where services are available 99.999 percent of the year and therefore down no more than 5 minutes and 15 seconds per year. Google's Gmail SLA, at 99.9 percent uptime, promises downtime of less than 9 hours per year.
That might not be five nines, and it's for Gmail only today, but Google chooses to see the glass as half full.
"We talk to customers, and 99.9 percent is mostly much higher than most organizations with their internal service today," Chandra said.