PHP Client Hangs Apache: Any Ideas?

[Chris Bolt]

> I'd like more info on this, this has never once occured for me and we
> use persistent connections in production.  If you could provide a
> scenario that helps reproduce this I would certainly work to fix it.

Well, to clarify, I'm using the pure PHP client. It's certainly not the 
most reproduceable bug. When I was experiencing it, it would only happen 
on one of six web servers at a time. I think it's caused by a php script 
not finishing correctly, leaving the persistent connection in an 
undefined state, so that the next time the connection is used it blocks. 
It's been months since I disabled persistent connections though, so this 
is all from memory.

> As to Greg's issue, we had a couple additional emails off list.  I think
> part of the problem may be that he is running memcached on 2.4.x linux
> kernels using select() as the polling method.  We have found memcached
> to be unreliable when using select() and to slow down immensely
> sometimes hanging, but to run perfectly with epoll under 2.6.x.

We're using epoll on 2.6.