What are the best caching practices for Magento?

1 Types of caching

Magento offers several types of caching, each with a unique function and scope. You can enable, disable, and refresh them from either the admin panel or the command line. Among the most popular types are the configuration cache, which stores the configuration settings from the app/etc folder and the database; the layout cache, which stores layout files that define page structure and appearance; the block cache, which stores the output of individual blocks; the page cache, which stores entire HTML output of pages with either the built-in full page cache (FPC) or a third-party solution like Varnish or Redis; the EAV cache, which stores entity attribute value (EAV) model used to store product and customer data; and finally, the collections cache, which stores results of database queries that fetch multiple records.

2 Cache configuration

When configuring your cache settings, you should take into account several factors such as server resources, traffic patterns, content updates, and extensions. Generally, you should enable all the relevant cache types unless you have a specific reason to disable them. Additionally, it's beneficial to use a separate cache backend for each cache type to avoid conflicts and improve performance. For example, you can use Redis for configuration, layout, block, and collections cache and Varnish for page cache. Moreover, you should adjust the cache lifetime based on the frequency and importance of your content changes. Utilizing cache tags and identifiers to group and label your cache entries can help you easily invalidate or refresh them when needed. Lastly, monitoring your cache hit rate and size is crucial for optimization; you can use tools like Magento Cache Clean or Magento Cache Warmer to automate the process.

4 Cache testing

Cache testing is essential to verify that your cache is delivering the expected benefits, and should be done before launching the site, as well as regularly afterwards. To do this, you should use tools like curl, wget, or browser dev tools to inspect the headers and content of cached pages. Additionally, Google PageSpeed Insights, GTmetrix, or WebPageTest can measure the performance and speed of cached pages. Furthermore, Siege, JMeter, or LoadImpact can simulate different levels of traffic and load on cached pages. In addition to this, New Relic, Datadog, or Magento Performance Toolkit can monitor and analyze cache metrics such as hit rate, size, lifetime and response time. Finally, Magento Coding Standard, Magento Extension Quality Program or Magento Marketplace can check the quality and compatibility of extensions and themes with your cache.

5 Cache troubleshooting

Cache troubleshooting is an essential process for identifying and resolving any problems or errors that may occur with your cache. As soon as you notice any signs of malfunction or degradation, you should review and diagnose the cache issues by using Magento logs, the cache backend logs, and the web server logs. To get more information about the cache issues, you can enable more detailed and verbose logging by using Magento debug mode, the cache backend debug mode, and the web server debug mode. Furthermore, you can disable or bypass the cache by using Magento developer mode, the cache backend developer mode, and the web server developer mode to isolate the source of the cache issues. Additionally, you can use Magento CLI commands, the cache backend CLI commands, and the web server CLI commands to perform various cache operations. Lastly, you can use Magento support resources, the cache backend support resources, and the web server support resources to find solutions and guidance for your cache issues or contact experts for help.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?