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

[Angsuman Chakraborty]

> 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.

Exactly the same situation here. In fact I was as surprised as you were with the results. We repeated the tests over several configurations with same results.
Then I understood. WordPress 2.0.3 already includes caching. It just so happens that their caching mechanism alone is more efficient than Wp-cache 2. I will share the results on Monday when my developer who did the testing is back.

> 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.

None of the above are an issue. In fact feel free to repeat the tests yourself. This is what I did:
Selected a large amount of url's from the web site. Then took a random subset and tested with one configuration, incrementally increasing the number of threads. After completion I cleared the cache and repeated for the other configuration. The results are averaged. Several runs were made to rule out statistical errors.


> 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.

You are forgetting WordPress 2.0.3 also does caching the same way as wp-cache 2. So it is really a comparison between caching systems.

Hope that clarifies,
Angsuman

Simple Thoughts <http://blog.taragana.com/>   Hot Computer Jobs




-----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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