Help setting up Memcached in Craft 3

Question

We want to use Memcached but are struggling to find Craft 3 specific config examples and documentation.

The docs mention several things that seem to lead to dead-ends:

App config docs here show how to configure the component in config/app.php. But in terms of 'enabling' that component, the docs here say that cacheMethod might need to be used, presumably in config/general.php, but the link to cacheMethod goes nowhere. Also here in the changes in v3 article, is says that cacheMethod has "been removed entirely" and instead point readers to Configuration → Data Caching Config which is a missing section.

In terms of the server setup, Memcached is enabled and we have 2 nodes/hosts available.

Very confused, please help.

Answer 1

The docs here are what you need: https://docs.craftcms.com/v3/config/app.html#memcached-example

Which is 99% exactly what Yii uses (since they have an example of using multiple servers): https://www.yiiframework.com/doc/api/2.0/yii-caching-memcache

Answer 2

Thanks to the Craft support team who responded here and via email. Some of the docs/links I mentioned have since been corrected.

Here is the salient part of the reply I got from Brandon at Craft:

"...So to be clear, the only thing you need to do to get Craft to use Memcached is follow our Memcached Example from the Application Configuration page. That code should be placed in config/app.php, and you will need to customize the config values as needed, and create the MEMCACHED_USERNAME and MEMCACHED_PASSWORD environment variables (named whatever you want as long as you update the config file appropriately – or you can just hardcode the values but we wouldn’t recommend that)."

I can confirm that this works.