Friday's Google outage that downed Gmail, Google+, Calendar and Documents for users around the world was caused by a software bug, according to a statement released by Google Friday evening.
The culprit, said Google, was an internal software bug that ultimately caused users' data requests to be ignored, which then caused errors within Gmail and other Google services.
"An internal system that generates configurations — essentially, information that tells other systems how to behave — encountered a software bug and generated an incorrect configuration," said Ben Treynor, Google's VP of Engineering, on the company's blog. "The incorrect configuration was sent to live services over the next 15 minutes, caused users’ requests for their data to be ignored, and those services, in turn, generated errors."
Google apologized for the outage, which, it reported, lasted 25 to 55 minutes and affected as many as 10% of users. The company also said they are in the process of putting systems in place to prevent any similar problems in the future.