[wp-hackers] wp-cache2 performance (was apache 2.2.2 upgrade)

Sat Jul 15 03:13:02 GMT 2006

I'm working on testing some of the caching features built in to both 2.2.2
apache and MySQL 5.xx as opposed to using wp-cache,  - prior to upgrading
Apache, etc. so, something like 1GB mem/80gb HD (7200rpm)/ and something
close to 2G processor which is about how my dev box is configured (red hat,
v 7.1), this box also runs my personal web site, and a couple of other
relatively low traffic sites. for a while I was letting a friend store his
eBay images on the box, so it was really getting hammered, something like
250K images/hits/day. so, under that load plus my site (traffic varies from
around 10k hits/day to more than 50k depending on what I have going on, wp
was taking around .55 seconds to load the "home" page with the cache
enabled, and sometimes as long as 2.xx seconds (a few times even WAY longer)
without. So I'd have to agree that there's no doubt the WP-cache is a great
plugin and it certainly works. 

As I mentioned, I'm going to play around with some of the newer caching
features of Apache 2.2.2 and MySQL 5.xx without the WP cache first, then
with the cache to see what kind of difference if any there is. 

One interesting concept I think would be playing around with the DB and
making use of things like views and stored procedures, etc, in the past I've
done a good amount of work with Oracle and MS-SQL, and we've seen tremendous
benefits from things like using pre-compiled code within the db, well
written views and sp's, etc. So, I think performance wise the newer versions
of Apache and MySQL in particular could really have an impact, especially on
a busy site. I have a couple of projects in the pipeline at the moment, and
to be honest, I'm a little nervous about using WP for them because I know
that they're going to be pretty heavy traffic sites, with definite potential
for the occasionally digg-dugg/slashdot pounding. 

I don't really like many of the alternatives to WP out there, but something
like the platforms that "publish" some content to "static" html pages would
make me a little more comfortable for these kinds of projects, rather than
relying on the DB for everything. So like I said, based on my initial
playing around with 2.2.2 and the file-caching capability, that pretty much
transparently gives WP similar capabilities as the "publish" type platforms,
but should also be much more efficient. Of course the production box for
those sites is a dell PowerEdge dual 1.5Ghz Xeon/2GB ram/270GB raid 5 box
which will only be running two or three sites, so I'm thinking that should
be more than sufficient for the occasional digg/slashdot crush. 

/**************************************
Christopher J. Hradil
chradil at comcast.net
http://www.hradil.us
973-809-4606
**************************************/

-----Original Message-----
From: wp-hackers-bounces at lists.automattic.com
[mailto:wp-hackers-bounces at lists.automattic.com] On Behalf Of David Chait
Sent: Friday, July 14, 2006 2:27 PM
To: wp-hackers at lists.automattic.com
Subject: Re: [wp-hackers] wp-cache2 performance (was apache 2.2.2 upgrade)

All the sites I've ever worked on performance problems with have had
significant performance boosts from wp-cache.  My own site has used
Staticize (the precursor) to survive a slashdotting.

It really depends on server config.  I mean, I guess it's possible if your
disk caching sucks (small cache, slow drives, whatever), and your MySQL
memory caching is huge, and a fast cpu, then dynamically processing the
pages is faster than wp-cache checking stuff and loading the thing in off of
disk (especially big pages).  That'd certainly be HD dependent at that
point.

Otherwise, I'd be shocked that loading a cache file from disk (which should
be in disk cache/memory for frequent data) takes longer than processing the
main query, plus running the various transformation code, plus plugins,
plus...  Just wouldn't make physical sense based on the code execution. 
Well, again, unless disk is slow and cpu is fast -- AND maybe you have an
opcode cache running, which would significantly impact performance.

Most shared hosts have fast drives, slow SQL, and no opcode cache. ;)

-d

----- Original Message -----
From: "Angsuman Chakraborty" <angsuman at taragana.com>
To: <wp-hackers at lists.automattic.com>
Sent: Friday, July 14, 2006 2:07 PM
Subject: RE: [wp-hackers] apache 2.2.2 upgrade

Today I was running some tests with wp-cache 2 as I am planning to upgrade 
my Simple Thoughts ( http://blog.taragana.com ) site to WP 2.0.3. The 
results surprised me.

WordPress 2.0.3 consistently performs better without WP-Cache 2 than with 
it, by a significant margin. I triple checked my results.
Have anyone else tested? Also we experienced more page load failures in 
heavy load (stress testing) with WP-Cache 2 than without.

So you might be better of without WP-Cache 2 than with it.

And yes as Jamie has pointed out WP-Cache 2 is very likely the cause of your

blank screen problem.

Have a good weekend,

Angsuman
Work: http://www.taragana.com/
Blog: http://blog.taragana.com/

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