Google has apologised after the notification system for its recently launched social networking service malfunctioned on Sunday and sent out numerous spam invitations.
Vic Gundotra, senior vice president of engineering at Google, told users that the system had run out of disk space, and apologised for any inconvenience.
"For about 80 minutes 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," he posted on Google+.
"We didn't expect to hit these high thresholds so quickly, but we should have. Thank you for helping us during this field trial, and once again, we are very sorry for the spam."
Reaction to Google+ has been generally positive since its launch at the end of June.
The service is able to seamlessly integrate with other Google products such as Docs, Gmail, Google Chat, Places and YouTube. The company is planning to launch a business-only version of Google+ later this year.
However, the service has not been without its problems. Immediately after its launch Google+ was targeted by scammers who sent fake invitations in an attempt to promote pharmaceutical web sites.
Many people have also been frustrated at being unable to sign up to the service as Google has restricted access.
The tight control over the number of users could have been a ploy to create interest in the social networking site, but could also be down to a lack of resources.
V3.co.uk has gone through the key features of Google+ and has pitted the Google+ Hangout feature against Facebook's integrated video chat to see which one comes out on top.
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