Facebook says outage was 'worst' in more than four years

By Suzanne Choney

Update: 10 p.m. ET:

Facebook said Thursday’s outage, which lasted about 2.5 hours, was the “worst outage we’ve had in over four years,” according to Robert Johnson, the site’s director of software engineering. Johnson provides a detailed explanation here, but said basically that “the key flaw that caused this outage to be so severe was an unfortunate handling of an error condition. An automated system for verifying configuration values ended up causing much more damage than it fixed.”

Facebook now says a widespread outage has been resolved and the site should be back to normal.

"Today we experienced technical difficulties causing the site to be unavailable for a number of people," a company spokesperson said. "The issue has been resolved and everyone should now have access to Facebook. We apologize for any inconvenience."

The outage, which lasted several hours Thursday, was the second day in a row the social networking site had problems. Some users reported difficulties accessing Facebook on Wednesday, but Thursday's outage appears to be more widespread.

Facebook declined to give any more details about the source of Thursday's problems, saying only that the site was experiencing some "issues, causing Facebook to be slow or unavailable for some users."

The spokesperson also said Thursday's problems "are unrelated to yesterday’s issues."

Facebook has more than 500 million users worldwide. Among the comments during the outage, below, on this blog, from frustrated users: Delean Bindle, who wrote: "I can't get on either. I get the same message, Internet server is down. Yesterday and earlier today I kept having to refresh the page or game, all the time," and from "Momskie": "Hope it comes back on ... im in missions in mexico & stay in touch with family this way....guess GOd will turn it back on when He gets ready...hopefully soon.."

The Associated Press reported that in addition to U.S. Facebook users, those in Europe and South America experienced problems.

Facebook was severely crippled before when the site slowed to a crawl in August 2009, at the same time Twitter suffered a complete outage. Both sites were victims of a denial-of-service attack, in which hackers take control of a massive number of computers and aim to inundate the site with traffic, preventing legitimate users from getting through.

At that time, the Associated Press noted: "The attack was targeted at a blogger who goes by 'Cyxymu' — the name of a town in Georgia — on several Web sites, including Twitter, Facebook and LiveJournal."

It is not known yet whether a similar problem happened Thursday. But both Facebook and Twitter had problems this week. On Tuesday, Twitter was struck by a hack which resulted in strange tweets of blocked-out text propagating themselves, causing popup windows to open.

As reported then: "Twitter said in a blog post the problem was caused by "cross-site scripting," which allowed users to run JavaScript programs on others' computers, turning tweets different colors or causing the pop-up boxes to appear. Some users, Twitter added, took things a step further and included code that got people's accounts to re-tweet the messages without their knowledge."

Another Facebook user, posting comments here, Vicki B-2408394, said with Facebook's "upgrade" to the site Wednesday, "Typically, when they have done changes to the site, there have been glitches for up to a week following the upgrades.

"With the amount of users on the site, this becomes rather frustrating, as many have gone to using it as their primary mode of quickly disseminating information," Vicki B-2408394 wrote. "It is also used by many as a gaming platform to launch many on-line games. Slowness was noted by many this morning, as the site was taking longer than usual to reload pages. About an hour ago, there was no access to the site at all."

The point — about Facebook's growing importance as a communication tool — is on the money. In the U.S., Web surfers are spending more time socializing on Facebook than searching with Google, according to recent data from researchers at comScore Inc.

"In August, people spent a total of 41.1 million minutes on Facebook, comScore said, about 9.9 percent of their Web-surfing minutes for the month," said the AP in its story about the report. "That just barely surpassed the 39.8 million minutes, or 9.6 percent, people spent on all of Google Inc.'s sites combined, including YouTube, the free Gmail e-mail program, Google news and other content sites."