poll vs epoll performance

Brad Fitzpatrick brad@danga.com
Mon, 17 Nov 2003 10:05:16 -0800 (PST)

How fast can you ping a host on a 100Mbit lan?  0.1 ms.
What's 400 * 0.1ms?  About a half second.

You're wasting all your time sending packets around.  Like Avva said, use
get_multi, or switch to a gigabit network, or both.  Using epoll may help
a tad, but that's not your current problem.

- Brad

On Sun, 16 Nov 2003, Richard Jones wrote:

> Hi all,
> we're running memcached on a couple of xeon boxes, using poll on both, epoll
> isnt installed
> i noticed one php page making around 400 induvidual GET requests to memcached,
> total memcached time take was 0.5 seconds. all requests were cache hits.
> how many memcached requests might a typical LJ/slashdot/any webpage make, and
> how long does it take to process them all? I'm interested in ways to reduce
> that 0.5 seconds
> each request was fetching a fairly small php object. (100mbit lan) i'd like to
> know if this is par for the course, or would the time taken decrease a lot if
> we were using epoll?
> what about using get_multi so all keys are passed in an array, this shouldnt
> make any speed difference, because the socket connection is already open so
> it is not cutting down on any connection overhead..right?
> Thanks,
> Richard.