WP Super Cache is very simple on the WordPress backend to configure and it is the most powerful WordPress Cache Plugin if properly configured. Configuring WP Super Cache with a particular server might not be very easy task as for the best performance sometimes it requires to know whether some softwares are installed or not.
There is problem as many leading Cloud Based Server providers will not let you know their proietary blend, however Rackspace and Media Template provides enough articles for Configuring WP Super Cache as a whole and with CDN.
Practically, it is not possible for us to try all CDN in the existing World and write a master tutorial which can help Configuring WP Super Cache. This tutorial will help in Configuring WP Super Cache with Rackspace Cloud Files, which uses Akamai CDN. Akamai supports both Origin Pull and Origin Push. We will show a fail safe method.
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Understanding the quality of CDN while configuring WP Super Cache
With Rackspace, you can easily use Rackspace Cloud Files, which is actually Akamai CDN. It is important to understand where your majority of the traffic are from. In our case it is U.S., we need not to bother that much with the coverage of any CDN as most CDN from U.S. has enough nodes in U.S.
Also, for Rackspace, it is very important to allow a period of 3-5 days after server migration while configuring WP Super Cache if you are operating from any Country from Eastern Region, it is undocumented but it is our observation and its quite logical that the servers will produce the optimal result after running the website for few days.
In case of Rackspace Cloud Files, you can not increase the TTL more than 72 hours from the control panel (right now), but you can increase up to 50 years with API. Also, if you allow a time, with the behavior, the Edge servers will change the TTL automatically. In other words, your performance will be better with time, without much intervention. Rackspace has said that they will increase TTL option up to 50 years right from the Control Panel soon, so, you can actually start with a longer TTL.
Configuring WP Super Cache With CDN
We will show the method for Configuring WP Super Cache, that works both with Origin Pull and Origin Push.
Download CDN Sync Tool Plugin, which has default options to configure with Amazon S3 / Cloud Front, NetDNA / MaxCDN and Rackspace Cloud Files.
Configure your CDN Sync Tool properly by going through the setting and entering the required url, username and password. If you are using Rackspace Cloud Files, create a container from your Rackspace Control Panel > Cloud Files :
In CDN Sync Tool Plugin, you will get options like minifying and combining CSS and js, just do as you like. In right hand of this CDN Sync tool, you will get Sync Files option :

Syncing will take a huge time if you are running for the first time. If you do not like Rackspace / any other CDN’s big name, you can create a CNAME like cdn.thecustomizewindows.com. Avoid it as it is can increase the chance of mixed content error.
Configuring WP Super Cache
Go to the WP Super Cache CDN option and tick the option saying Enable CDN Support. Default is wp-content, wp-includes, if you want you can add more. Click Save Changes and done.
The other way to copy all the files exactly like what CDN Sync Tool Plugin does, is to access the CDN container via Cyber Duck or any such software and simply copy pasting the static files of wp-content and wp-include.
Some has written about configuring WP Super Cache with own physical subdomain as “virtual” CDN. Do not waste your energy by doing so. We are configuring WP Super Cache to offload our server’s load and putting them to a cookieless domain which are geographically distributed closer to the visitors.
Creating a physical subdomain itself increase the burden on your database server, so practically it increases the load on your server. It is better to think configuring WP Super Cache with preload to speed up the pageloading time if you can not pay only few cents to few dollars per GB / month for a CDN.
Tagged With 82NS , CDN PULL PUSH
Nice article and before reading it haven’t any idea about CDN but thanks. Now its bit clear.
Awesome write up, I found that w3 didn’t set my leverage browsing cache beyond 72 hours, I had to follow bybe.net/blog/how-to-fix-rackspace-file-cloud-leverage-browser-caching-via-api-ssh.html and set it via the SSH, does W3 actually support the rackspace API completely? or did i do something wrong?
The current version of Rackspace Cloud Files / Akamai does not support the old php version (available via GitHub) of API. All cache plugins and CDN tools uses the older one due to complexity of the API. That is why it does not work.
You did it rightly. You can use MaxCDN to get easier control of expire headers (for CDN) : http://thecustomizewindows.com/2012/03/maxcdn-versus-rackspace-cloud-files-head-to-head-test-and-result/
Hello,
what do you mean by physical subdomain? and how can it increase the load on the server?
thanks you
John