Don't use MongoDB

I would love to see a thorough approach in which such claims are actually shown and can be reproduced. This helps everyone immensely...from 10gen to people looking to adopt.

This rant is completely outdated and it shows: "pre transaction log" "fixed this in 1.8". You realize MongoDB is at 2.0 now and the transaction log was introduced in 1.8, right? Yes, MongoDB had problems but since the transaction log it's pretty good. I have used MongoDB since early 1.3 and I knew what I was doing and we never lost a bit of data. There is a tradeoff -- while MongoDB handled write load easily that a MySQL box with 2-3 times the RAM , I/O capability couldn't at all we understood the bleeding edge of using MongoDB back then. We have, for example, kept a snapshot slave which shot itself down often, took an LVM snapshot then continued replicating. Never needed those.

We have meticulously kept a QA server pair around and the only time when I have ran into a data loss problem was when I have hosed one of those -- but only one and even the QA department could continue (and hosing that server was me not knowing that Redhat 5 had separate e4fsprogs and e2fsprogs, only partially MongoDB fault but now it works without O_DIRECT so even this would not be a problem any more) . Never understood for example how could foursquare get where they got to -- didnt they have a QA copy similarly?