Caching performance

[danh42]

I'm working with a PrestaShop site that's currently getting around 100 page views per minute, and that number is expected to increase in the near future. The site is running on its own quad-core VPS with WHM/cPanel (Apache 2.4, PHP 5.4, fcgi), and there are no other sites hosted on that server.

 

I've been making various performance improvements, but every time I try enabling caching through PrestaShop, performance drops like a rock. I've tried the file system cache, xCache, and APC, and each one sent response times skyrocketing and had to be reverted. I have New Relic doing transaction tracing, and the cache-related classes are always what's taking up so much processing time:

 

 

Here's is a screenshot of performance before and after disabling APC (config), with the blue line indicating the approximate time I disabled the caching option in the back office:

 

 

I could maybe understand if I'd just configured one caching daemon incorrectly, but I've tried two different ones plus the file system cache, and they all significantly hurt performance. What could be causing this? I think the site could benefit from better caching, but I haven't gotten any cache setup to actually work properly.

Edited January 10, 2015 by danh42 (see edit history)

[Richard S]

We are usually using OpCache from PHP side and default PrestaShop cache. We have not seen any problems with that at least for now.

[JPresta.com]

I also tried the file system cache on one of my site and it also hurt performances. That's why I developped PageCache :-)

[n_s_simpson]

Hi, I use OPCache.

 

In PS admin the bottom caching option is turned to "NO". Is that right.

 

Would it be better if I turned to "YES" and selected the "File System" option or would that conflict/override OPCache?

 

Cheers

 

Nick