Ljubljana, Slovenia

Cache

Sun, Jan 8, 2017

Improving NGINX LUA cache purges

A few months ago I wrote an article on how to clear single cache items from NGINX with LUA, with a simple O(1) complexity. While it’s certainly possible to use it for simple and low-impact cache invalidation, there is a need for deleting huge parts of the cache with a wildcard pattern.

Purging cached items from NGINX with LUA

Those of you any how familiar with scaling up a service, will by now be familiar with NGINX as a strong workhorse, when it comes to proxy HTTP requests between multiple backend servers. There’s one thing the open source NGINX version doesn’t do however - you can’t issue a PURGE request against a cached resource and delete it from the cache. That is, until we bring in LUA.