Magento

UPDATE: The “Fanatical” support people at Rackspace were able to optimize my server settings to run Magento.

Response times are now much better (1-2 seconds for most requests, 4 seconds for add-to-cart).

I have requested permission from Rackspace to allow me to post the specifics of what they did in this thread to help others having severe performance issues.

Standby…

Travis

Permission granted!

The following is a quote from my “Fanatical” Tech Support specialist at Rackspace.com of what he did to my server to make Magento work:

Rackspace said:
2008-07-22 16:23:17 (UTC-6)

Travis,
Hi, I’ve looked over your server and I’m not seeing any issues that would explain the reported slowness. I have how ever made some tweaks to your system.

I’ve worked with Magento here at rackspace quite a few times so I *might* be able to help you out.

First off, I made some changes to your system, I increased the APC.shm.size to 128 This will allow more data to be cached by apc, in theory it’ll store more data.

I also made some changes to the vhost.conf file for the shop site, historically disabling open_basedir allows magento to work slightly better.

I also made some changes to your mysql database server.

I increased the table cache and enabled the slow query log, this will allow us to nail down if the problem is database related or something else. I also decreased query_cache_size & key_buffer_size as mysql was using over 95% of the system’s memory, this is causing httpd and other processes to use a lot of swap space, not good.

Mysql is logging all queries that run over 2 seconds to
/[...]/mysqllogs/slow_log

Check this out every now and then, its pretty awesome for knocking out database related performance issues.

I also noticed that your iowait was pretty high, hovering around 5-10% This is very bad as your system is having to wait on the disk before it can serve data. This will slow down website and drive up load times.
This was probably due to your mysql misconfiguration.

[...]

Thanks,
John Trenholm
RackSpace Managed Hosting

After those changes were made to my managed server, Magento started to perform great with response times of 0.8-2 seconds.

I have just written a tutorial on compiling php5 specifically for Magento on LiteSpeed web server.

Magento + LiteSpeed + xCache + PHP5 through LSAPI module = Crazy FAST

Hopefully this should give everyone the excellent page load times that I’m seeing!

http://www.evanbrassart.com/2008/10/compiling-php-on-litespeed-for-magento/