On Mon, Nov 28, 2011 at 8:59 PM, Neil Harris <neil(a)tonal.clara.co.uk> wrote:
I hadn't thought properly about cache stampedes:
since the parser cache is
only part of page rendering, this might also explain some of the other
occasional slowdowns I've seen on Wikipedia.
It would be really cool if there could be some sort of general mechanism to
enable this to be prevented this for all page URLs protected by memcaching,
throughout the system.
I'm not very familiar with PoolCounter but I suspect it's a fairly
generic system for handling this sort of thing. However, stampedes
have never been a practical problem for anything except massive
traffic combined with slow recaching, and that's a fairly rare case.
So I don't think we want to add that sort of concurrency protection
everywhere.
Roan