Redis is a Key/Value storage that allows you to save data outside your database with blazing fast access. Shopware supports the usage of Redis for session and cache handling. Here is a sample of a docker setup that adds a new Redis instance to your Docker network. Just add the container and make sure its on the same network.
Now make sure you configure the Redis instance to be used either for session handling, cache handling or both.
Add the following to your ".env" file:
Please note, that you also need to use it for specific parts in Shopware.