Google+ disk space slip causes spam tsunami

Google might be trying to take on the mighty Facebook with its new social networking service, but it looks like it could do with allocating a slightly larger budget to the project after a disk space flaw saw users bombarded with e-mail notifications.

The Google+ service is still running in a limited field trial mode, with the advertising giant occasionally opening the service up to new users before locking the door once more. The reason for the strange sign-up process is generally considered to be an example of artificial scarcity in order to drum up hype for the site, but Sunday's sudden surge of spam suggests otherwise.

Users signed up to the service opt in to e-mail notifications by default: every time a user is mentioned in a message, added to a circle, or one of a range of other important events occurs, an e-mail is sent to their registered address. For those without Android smartphones, it's a handy way to keep track of what's going on in near-real-time.

Sadly, the process went somewhat wonky on Sunday when the server responsible for tracking which notifications had already been sent out ran out of disk space, causing the generated notifications to be sent out repeatedly in a torrent of e-mail aimed at the service's users.

"For about 80 minutes," explained Google+ engineer Vic Gundotra, "we ran out of disk space on the service that keeps track of notifications. Hence our system continued to try sending notifications. Over and over again. Yikes.

"We didn't expect to hit these high thresholds so quickly," Gundotra added, "but we should have."

The reason for the sudden growth in the service is likely due to a range of loopholes that allowed lucky users to invite their friends into Google+ before the official invitation mechanism was in place. Thanks to these loopholes, the number of people using Google+ has grown at a rate the company was likely not expecting.

That's something Google is looking to fix: aside from allocating a beefier server for looking after the notification tracking, the company is thinning the ranks of Google+ users by banning businesses - which, it is thought, will be invited back when the company launches a corporate-themed Google+ service - and, more recently, those users who prefer to be known by a pseudonymous or virtual identity.