I brought up a question in the forums and mentioned a server crash.

http://groups.google.com/group/mongodb-user/browse_thread/thread/d651ded2208dc87e/e22901c257054231#e22901c257054231

In that thread I said that adding indexes fixed the crash. We'll, ... it didn't. During testing on our dev server I got the crash today. I think what's new here is the 1.2.1 background delete functionality. I'm also seeing "key seems to have moved in the index, refinding. found:1" quite a bit.

I was running 2 applications.

I was running only one processes of type "app1". This is a very fast app that hits mongo very hard.

1. background thread requested delete on old records
2. background thread was several different ordered queries, then rewriting some of the records
3. foreground thread was querying and inserting records

I was running 10 processes of type "app2"

4. slowly gets various data, queries mongo, and reads and writes a fairly large record