Microsoft said that a configuration change that was mistakenly moved from testing onto the live Bing.com site was to blame for an outage Thursday that left Microsoft's search engine completely inaccessible for more than half an hour.

A Microsoft representative told CNET on Friday that the problem appears to have come when something being tested was moved onto the live site.

'A configuration change was mistakenly propagated to production from staging,' the representative said. 'It was supposed to stay in the test environment--it was a mistake.'

In a blog posting that went up late on Thursday night, Microsoft Senior Vice President Satya Nadella said that a change made during testing had 'unfortunate and unintended consequences.'

'As soon as the issue was detected, the change was rolled back, which caused the site to return to normal behavior,' Nadella said. 'Unfortunately the detection and rollback took about half an hour, and during that time users were unable to use bing.com.'

And here I thought Microsoft was just trying to be energy efficient by running Bing only 23 hours a day.

Nadella said that Microsoft is exploring what went wrong to make sure it doesn't happen again. The outage came just a day after Microsoft announced a variety of changes to Bing, including added detail for some results and improved mapping tricks.

On the plus side, though, as ZDNet colleague Larry Dignan pointed out, at least people noticed there was an outage. It's all about mindshare, right?

Source: Behind last nig...