If you were unable to access Gmail, Google+, Google Calendar, Google Drive, and other online services from The Big G earlier today, you were not alone. A widespread outage was reported in the late morning/early afternoon US time. Google seems to have cleared up the issue, but just to let everyone know what's up, Google's Vice President of Engineering Ben Treynor took to the company blog for both an explanation and an apology.
Earlier today, most Google users who use logged-in services like Gmail, Google+, Calendar and Documents found they were unable to access those services for approximately 25 minutes. For about 10 percent of users, the problem persisted for as much as 30 minutes longer. Whether the effect was brief or lasted the better part of an hour, please accept our apologies—we strive to make all of Google’s services available and fast for you, all the time, and we missed the mark today.
The issue has been resolved, and we’re now focused on correcting the bug that caused the outage, as well as putting more checks and monitors in place to ensure that this kind of problem doesn’t happen again.
Treynor goes on to explain that one of Google's internal configuration systems sent out an automated update to a variety of services. This update was affected by a software bug, which in turn generated errors for users - some for just a few minutes, some for a few more. Google's engineers were alerted in less than seven minutes, and had repaired the error in less than 20, though some users experienced issues for a little while longer.
Google assures us they've found and fixed the original problem, and that new systems are being put in place to prevent it from happening again. As frustrating as an outage for such a vital company can be, it's as well to remember that they provide service to hundreds of millions of people, and most of them access it for no monetary charge. I think a little human error can be forgiven for reaching only 99.99% uptime.
Source: Official Google Blog