That's not quite true; Redis also provides an append-only-log mode of operation just like conventional databases, and of course it can be run with master-slave

That's not quite true; Redis also provides an append-only-log mode of operation just like conventional databases, and of course it can be run with master-slave replication. I wrote a bigger reply here: http://news.ycombinator.com/item?id=3010949 http://news.ycombinator.com/item?id=3010949