Facebook said on Friday that users around the world had trouble accessing its services for hours because of changes to its system.
“Sincerely sorry to anyone who hasn’t been able to access our products in the last few hours,” a Facebook spokesperson told AFP at around 21:30 GMT.
“We fixed the issue, and everything should be back to normal now.”
Website trouble tracker DownDetector showed a spike in reports of problems starting or using Facebook and its photo-focused Instagram network, as well as Messenger and WhatsApp, about three hours ago.
Facebook attributed the trouble to a configuration change on its computing platform and said it affected users of the social network and Instagram, Messenger and Workplace globally.
People took to Twitter to express their disappointment.
“What’s up with Instagram?” A tweet read that included a photo of cartoon character Bart Simpson sitting in a corner in apparent punishment.
“It hasn’t even been 4 days now and it’s already down.”
“Problems with Instagram, Facebook, Facebook Messenger and WhatsApp again!” Read the lament in the Downdetector chat forum.
Millions of people were unable to access Facebook, Instagram or WhatsApp for more than six hours on Monday, underscoring the world’s reliance on the platform owned by the Silicon Valley giant.
In an apologetic blog post, Facebook’s vice president of infrastructure, Santosh Janardhan, said the day’s outage was due to “configuration changes” on routers that coordinate network traffic between data centers.
Cyber experts think the problem boils down to something called BGP, or Border Gateway Protocol—the system the Internet uses to choose the fastest route to move packets of information around.
Sami Slim of data center company Telehouse compared BGP to “the Internet equivalent of air traffic control”.
In the same way that air traffic controllers sometimes change flight schedules, “Facebook updated these routes,” Slim said.
But there was a critical error in this update.
It’s not yet clear how or why, but Facebook’s router essentially sent a message across the Internet that the company’s servers no longer existed.
According to Facebook, the outage on Friday was not related to the one earlier in the week.
Experts say Facebook’s technology infrastructure is unusually dependent on its own systems.
Social media outages aren’t uncommon: Instagram alone has experienced more than 80 in the past year in the United States, according to website builder ToolTester.
Facebook’s services are important to many businesses around the world, and Facebook accounts are also commonly used to log into other websites.
My billions of people use Facebook’s apps monthly, which means outages could touch a large portion of the world’s population.