Could use some advice here.
We have a fairly high traffic site web site using WordPress. Currently we have two VPS servers managing the site, one that holds WP, one that holds MySQL. The WP servers uses W3 Total Cache with Disk Enhanced to avoid PHP processing.
The site has a history of using "Splash Pages" on big news stories. This is how these work.
Caching is turned off for the home page. A cookie is provided to users. New visitors are directed using a Header relocation command to a separate, cached page with the splash content. Return visitors are directed using a Header relocation command to a separate, cached home page. The problem is that we need to serve separate content on one page. Some dynamic processing must be done. My solution above allows a fairly lightweight process (check a cookie) and a forward to a cached page. It works fairly well, but during very heavy traffic days, even that marginal processing adds enough processing to slow things down and sometimes cause gateway errors (we run nginx/PHP-FPM).
The splash pages do well with drumming up buzz (and actually do better with advertisements), so not doing them is not an option.
How would you manage this problem?