Mongodb: Does not seem to respect capped size limit
OK, we solved this.

Issue is that mongo auto creates the collection when incoming data comes in.

So the problem was:


Drop collection 
// transactions are coming in 
Create collection as capped


But #3 comes too late, as the collection is already present, as not capped, because of #2.

Solution:


stop mongo
bring up mango on non standard port // to prevent auto creation of collection
create collection as capped
stop mongo, bring it back up on regular port


Now I have a capped collection!