[cnagele]

Hi everyone. Chris here from Postmark.

I would say that MongoDB durability used to be an issue, but now with journaling and replica sets it's not as much of a concern.

There were two reasons why the secondary was less capable than the primary. First, the data had become very fragmented due to our frequent purging. And second, we were in the middle of an upgrade to our servers and that one had not been tackled yet. The primary failure came at a bad time. I could have clarified that better in the post.

Regarding capped collections, yes they are faster. The problem is that they can't be sharded. With our dataset that would not allow us to scale.