DRUPAL 9 CACHE CONTEXTS HOW TO
DRUPAL 9 CACHE CONTEXTS INSTALL

When the memcache service sets a cache entry, it stores this as a permanent item in Memcache, because validation is always checked in cache get. This Service is defined by the Memcache module and implements like any other cache back end the CacheBackendInterface.This interface is used to define a cache back end and forces classes to implement the necessary cache get, set, delete, invalidate, etc. As explained before, we are telling Drupal to use the service as cache back end.

To be able to test your setup and finetune Memcache, you should know how Memcache works. Setting up those specific bins to use Memcache can be done with the following lines in settings.php. Putting cache_render and cache_dynamic_page_cache into memcache is the safest and most beneficial configuration: the larger your site, the more queries those tables endure. Therefore it is recommended to always check if the cache bin is only used to store cache entries and to fetch them later on while not depending on it to be in cache. In Drupal 7, for example, the form caching bin could not be offloaded to Memcache, because it can happen that the cache key gets overwritten with something else resulting in a cache miss for specific form cache entries. However, doing so is not recommended because it cannot be guaranteed that all contrib modules only perform simple GET and SET queries on cache tables. Once you have installed memcache and have made the necessary changes to the settings.php file to connect to the memcache service, you need to configure Drupal so it uses the Memcache cache back end instead of the default Drupal cache back end. If your server is running on a different server or listening on another port you need to modify the connection by changing the following line in your settings.php. This means that the memcache server is running on localhost and listening on port 11211. Once you have installed the module, it should automatically connect to memcache using the default settings.

This module is currently in alpha3 stage and ready to be used in production sites.

DRUPAL 9 CACHE CONTEXTS INSTALL

When you have the memcache server specifications, host IP and port you need to download and install the Memcache module, available here: By default, memcache will be running on port 11211.

DRUPAL 9 CACHE CONTEXTS HOW TO

You can find a lot of tutorials how to do this for your distribution, but if you use MAMP PRO 4 you can simple spin the memcache server up. Using Memcache allows you to directly offload cache bins into RAM, which makes cache sets, speeding up the cache along the way and allowing MySQL more breathing space.īefore you can connect to memcache, you need to be sure that you have a memcache server up and running. This means that your database is unable to process the cache sets queries in time and in worst case resulting into a down time of your website. Doing this on large sites with a lot of real-time visitors can lead to a lock timeout of MySQL, because the cache tables are locked by the cache rebuild function. This forms a potential performance bottleneck. Nevertheless, having to rebuild the whole render cache from scratch on a high-traffic website can result in a lot of insert query statements for MySQL. In previous versions of Drupal, the page cache bin was responsible for rendered output of a whole page.Ĭonsequently, the chance of having to rebuild a whole page in Drupal 8 is far lower than in previous versions, because the cache render bin will contain some blocks already available for certain pages - for example a copyright block in your footer. This means that cached data is aware of where it is used and when it can be invalidated, which resolved in two important cache bins responsible for holding the rendered output, cache_render and cache_dynamic_page_cache. The way data is cached has been overhauled and optimized in Drupal 8. Interested in how D8's flow has been improved and how to use Memcache for yourself in the best possible way? Read on! Flow improvements with Drupal 8 In this blog post, our technical lead Kevin guides you through the best caching strategies for Drupal 8.

Drupal 9 cache contexts