One of the biggest problems we found while working with a large WordPress multisite that utilises domain mapping was caching issues with the big caching plugin options such as WP Super Cache and W3 Total Cache. With good server setup, there isn’t a real need for many additional cache plugins that will eat up resources and in some cases actually make your site slower.
What I was looking for was a static cache plugin, a plugin that will generate a static HTML version of your page and serve the static version to visitors. WP Super Cache seemed like the solid option but after 6 months of testing, we found multiple issues on our multisite. These included login redirects for no apparent reason and limited per site options.
So what did we end up using? After a lot fo trial and error, we found Cache Enabler by KeyCDN. A very simple caching plugin that generates static HTML copies of posts and pages, what is really great about Cache Enabler is that you can independently configure for each site on your network. It works perfectly with domain mapping and doesn’t cause any painful login errors or our users.
CDN Enabler? If you manage a CDN through CloudFront or similar then try CDN Enabler also by KeyCDN to activate a content delivery network on a per site basis. Allowing different CDN URL for each site or going further and improving SEO by giving each site a relative CNAME.
I hope this short article helps other find a stable cache setup for their Multisite. Any questions or comments please leave them below.