If you want to test that your Redis cache is actually working with your cloud you can use the cmd “monitor”
redis-cli -s /var/run/redis/redis.sock
monitor
Now you will see live what is going on. Just do something with nextcloud and you will see the cache working.
Since both Redis and Memcached are both written in C using both at the same time might result in segfaults.
Test if Redis, Memecached or both are loaded.
php -m |grep 'redis\|mem'
Hopefully only Redis shows up. If you don’t see Redis then we enable it. In
/etc/php/7.0/mods-available/redis.ini
you should have
extension=redis.so
If it is not there then add it. If memcached is enabled you should be able to disable it with
phpdismod memcached
Restart everything just be be sure.