Just to add to this, I am using redis with a socket.
my config.php has the following:
‘memcache.locking’ => ‘\OC\Memcache\Redis’,
‘filelocking.enabled’ => ‘true’,
‘redis’ =>
array (
‘host’ => ‘/var/run/redis/redis.sock’,
‘port’ => 0,
‘timeout’ => 0.0,
),
So my test command was “redis-cli -s /var/run/redis/redis.sock MONITOR”