I've never had this issue pop up (I am not involved in any huge scale sites) but I have to believe this really isn't too common?

Also a 5 second Googling shows there's ways to set Redis up to stop writing but continue reading if you're running out of memory. If you really have that large memory needs then you're going to also run out of memory with this new lib on 1 machine.

It seems like Redis has more than enough options to prevent real problems from occurring once you do surpass your hardware requirements.