The render cache is a system using cache tags, cache contexts and cache invalidations. Like most Drupal developers I've worked with this system for years and thought I had it mastered. But I met my match this past year, with a very customized, large, slow, frequently updated, and authenticated-user-accessed D9 site. I 'just' wanted to fix the caching.

I got help from cache experts Fabian Franz (cache API creator) and Janez Urevc of Tag1. Janez will be joining me to co-present this session.

I've learned some gotchas in the system and some tools to find problems and get data. I'll be sharing what I know now that I wish I knew a year ago.

This talk is for backend developers who already work with and understand at least the basics of the cache API, and would like to further their cache API skills or improve a difficult site's backend performance.

Learning Objectives

Debug cache tags and contexts
Monitor cache invalidations and hit rate
Avoid common pitfalls including Views module cache gotchas

Prerequisites

Cache API Basics (Setting cache tags and contexts in custom code)

Synopsis

Learn how to debug Cache API problems to optimize performance