Redis for D7 @ploi (Predis)

- install module https://www.drupal.org/project/redis/releases/7.x-3.18 
- check if php redis is installed, if not, run: apt install php7.X-redis + restart php + redis
- copy at the end of settings.php:

 $conf['redis_client_interface'] = 'Predis';
 $conf['redis_client_host'] = '127.0.0.1';
 $conf['lock_inc'] = 'sites/all/modules/redis/redis.lock.inc';
 $conf['path_inc'] = 'sites/all/modules/redis/redis.path.inc';
 $conf['cache_backends'][] = 'sites/all/modules/redis/redis.autoload.inc';
 $conf['cache_default_class'] = 'Redis_Cache';

- download library https://github.com/nrk/predis and unpack into sites/all/libraries/predis

- check if is working by command redis-cli monitor (and browse web)