Google’s Gmail service was knocked offline in a huge failure that affected a “majority” of its millions of email users.
The tens of millions affected included consumers who get free Gmail and businesses that pay for a version for their employees.
The disruption, which lasted under two hours, was a reminder of the growing dependence on Google’s technology.
The free version of Gmail is the world’s third most-popular email program with some 149 million users worldwide in June, ranking behind the free email services offered by Microsoft and Yahoo, according to data from comScore Inc.
Yesterday’s disruption led Gmail users to get an “Unable to reach Gmail” error message as their computers tried repeatedly to reconnect to the service.
Google said it had taken some of Gmail’s servers offline for routine maintenance and underestimated the load that would place on other computers responsible for directing traffic to the appropriate Gmail servers.
Google said it was alerted to the failures within seconds. It said it has added capacity and made other changes to prevent similar incidents in the future. A separate outage on Monday had wiped out email to a “small subset” of users.
Though occasional disruptions are common, widespread outages involving Google’s services are rare. They are becoming a bigger threat to Google as it tries to sell more of its services to businesses.
Businesses are increasingly leaning on Google’s services because they are delivered over the internet instead of being managed in-house. That can save companies money and buy them more storage than they could otherwise afford. But many corporations are sceptical about outsourcing such critical tasks.
Google argues that web-based services are more reliable than those handled in-house, but big outages like yesterday’s add another challenge to selling to reluctant businesses.
Google says more than 1.75 million businesses use Gmail as part of Google Apps, which is Google’s answer to business software from Microsoft. It is a key part of Google’s strategy to inject its brand deeper into corporations.
The last major outage at Google happened in May, when millions of people were cut off from Google’s search engine, email and other online services after too much traffic was routed through computers in Asia.
About 14% of Google’s users encountered problems with the Internet’s No. 1 search engine. Those outages lasted about an hour.