Cassandra not ready for prime time? Or put to an inappropriate use?

(written by Lawrence Krubner, however indented passages are often quotes)

John Quinn has been fired from Digg. He was the main advocate of using Cassandra:

The new version of Digg, v4, is based on a distributed database called Cassandra, which replaced the MySQL database the site ran on before. Cassandra is very advanced—it is supposed to be faster and scale better—but perhaps it is still too experimental. Or maybe it’s just the way Digg implemented it (Twitter uses Cassandra, although not for its main data store, as does Facebook in places, but it obviously is not as battle-tested as it needs to be). Every engineer at Digg is currently just trying to keep the site up and running.

Quinn was the main champion of moving over to Cassandra, say our sources. Now the site is taking a huge hit, at least in the short term, because of that decision and/or how it was implemented, and Quinn is paying for it with his job. But it is not clear what else Digg should have done. Digg was originally built on the tried-and-true LAMP stack (Linux, Apache, MySQL, PHP) of open-source technologies, but it was straining under the load of Digg’s traffic. Replacing MySQL with Cassandra was supposed to help fix that. It came with its own set of larger problems instead.

In the comments someone points out that the story is lopsided since there is no quote from Quinn. I agree. I’d really like to hear his take on this. Does he feel using Cassandra was a mistake, or does the site simply need more time to be made stable? And, speaking of that, why wasn’t it tested more completely before being rolled out?