[ploxiln]

I worked at bitly for a couple of years, we used mongodb for one of our secondary datastores. We had the expertise to keep it working, but we really hated it.

It's this funny situation where some engineer starts off using it because it's very convenient to run, and maybe the data model is convenient. You scale it up a bit, debug it, tune it, stuff you'd have to do with any system. At the point when you're sure mongo really sucks, it's too late. The business and even technical management side always prioritizes some other project over replacing it, even though you spend a surprising amount of time each month maintaining the mongodb cluster (performance degredation that compaction doesn't completely fix, and other stuff...).

I get the sense that with 3.0.3 or so, mongodb is a real database now. But it's been years of pain and false advertising. I'd still always vote against it. (Even though at my current place some people started using it for a service... :(