Having Redis locally Create a selfsigned certificate. You can run this command on Ubuntu:   sudo openssl req -x509 -nodes -days 365 -newkey rsa: 2048 -keyout /etc/redis/redis.key -out /etc/redis/redis.crt You can leave all answers by default. One that is important is Common Name - if you have smth with dot in your hosts file (i.e. moodle.my or localhost) - put it there. Or add it to hosts first and put as Common Name. You might update ownership of those files to be owned by redis Update you redis config to user those certificates: port 0 tls-port 6379tls-cert-file /etc/redis/redis.crt tls-key-file /etc/redis/redis.key tls-protocols "TLSv1.2 TLSv1.3" tls-auth-clients no Restart redis by running /etc/init.d/redis-server restart Redis Cache Test config Config - Plugins -> Caching / Configuration /cache/admin.php Redis -> Add instance: Store name : some name Server : Redis server hostname from above Tick Use TLS encryption If your SSL certificate is for the correct hostname you can enter /etc/redis/redis.crt in CA file path , otherwise leave it empty, it will skip the verification. Save changes Confirm that there is a green tick in the Ready column for the store. Now you can either map individual cache definitions of types Application and Session to your newly created Redis instance, or, at the bottom of the page: Stores used when no mapping is present -> Edit mappings: Change Application and/or Session to your newly created Redis instance Save changes Plugins -> Caching / Cache stores / Redis /admin/settings.php?section=cachestore_redis_settings Test server : the name you gave yo your Redis server instance Tick Use TLS encryption Same reasoning for the SSL certificate as above Save changes Test Confirm that site is functioning without cache errors. Plugins -> Caching / Test performance /cache/testperformance.php For all tests: Confirm that Result for Redis is Tested . Note: Redis cache doesn't support REQUEST mode. Plugins -> Caching / Cache usage /cache/usage.php For all tests: Confirm that Redis store is used, either for the individual mappings, or across the board for the Application and Session types. Redis Session config.php Same reasoning for the SSL certificate as in Cache Store Config above. $CFG ->session_handler_class = '\core\session\redis' ; $CFG ->session_redis_host = '<Redis server hostname from above>' ; $CFG ->session_redis_encrypt = [ 'cafile' => '/path/to/redis.pem' ]; // or $CFG ->session_redis_encrypt = [ 'verify_peer' => false, 'verify_peer_name' => false]; Home page with debug panel at the bottom Confirm that Session is core\session\redis and that page opens without an error.