On 2010-08-17 12:37:01 -0600, Matthew Ehle wrote:
I highly doubt that apc cache is much faster than memcached.
It mostly depends on how the wiki is used (amount of read vs. write), but the general consensus is that APC is slightly faster for most situations.
As the former co maintainer of the wiki I know very well that the cache access was the fastest part of it. :)
In a proper config you got one memcached per webserver, and configure all memcacheds in the wiki.
Each web server has its own memcached daemon, which is used by only that web server. We can always pool them, but it would make very little difference for our setup.
well, except that you cache things multiple times and might hit stale caches that way. I would recommend to configure it to use all running mecacheds
a) you got shared storage, no matter on which webserver you get the request. I would assume that the APC is local to the machine. Yes, and that is why it is slightly faster. APC is accessed locally, while memcached is accessed through a network socket, even on localhost.
1. access via localhost is shortcutted in the kernel for tcp. so if you only use it via localhost the overhead is pretty low.
b) you can scale to much more cache with memcached than with APC. Yes, but we don't have enough data for that to be relevant quite yet. I run memcached to store up to 1GB of data, but I don't think we even come close to hitting that.
c) memcached is fast enough for wikipedia and even facebook (although they use it with udp in the mean time)
Agreed. I think that it is a perfectly acceptable solution. I just wanted to bring up the APC alternative as a possibility. I might have to look into running memcached with UDP, as that might cut some of the network overhead.
if you want to keep the localhost only solution, the recent memcached versions support listening on a unix domain socket (see -s param). anyway ... I think we are far away from the workload that warrants the switch to udp. darix -- openSUSE - SUSE Linux is my linux openSUSE is good for you www.opensuse.org -- To unsubscribe, e-mail: opensuse-wiki+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-wiki+help@opensuse.org