The Delicious Brains has a new tutorial posted sharing a method you can use to setup microcaching in Nginx for your WordPress installation and improve the performance of server requests by a large margin.
We’ve talked a lot about WordPress performance and hosting WordPress here at Delicious Brains. A common theme amongst those articles is the importance of page caching and how it’s arguably the best way to improve the performance of your WordPress site. [...] However, we’ve also alluded to the fact that page caching is difficult to implement on highly dynamic sites.
[...] In these circumstances page caching still has its place but the duration of the cache has to be significantly reduced. This is known as microcaching. Microcaching is a technique where content is cached for a very short period of time, usually in the range of 1-10 seconds. In this article, I’m going to demonstrate how to configure WordPress and bbPress with Nginx FastCGI caching.
They start off with some initial benchmarks performed using the Blitz.io service against a clean WordPress install on a Digital Ocean droplet. The first results are of a test with 100 concurrent users over 60 seconds (with not so great results). Then, using this method in the Nginx configuration, the site is retested resulting in much better performance but with one downfall - the pages are cached and no longer dynamic.
To resolve this they move to the "microcaching" solution, adding the caching to parts of the application that aren't the forum using the "X-Accel-Expires" header sent from WordPress. The post ends with a bit more tweaking to the configuration and some caveats to its use.