Fatal error: Uncaught Error: Class 'Redis' not found in /var/www/html/sites/all/modules/contrib/redis/lib/Redis/Client/PhpRedis.php:9 Stack trace: #0 /var/www/html/sites/all/modules/contrib/redis/lib/Redis/Client/Manager.php(142): Redis_Client_PhpRedis->getClient() #1 /var/www/html/sites/all/modules/contrib/redis/lib/Redis/Client/Manager.php(85): Redis_Client_Manager->createClient() #2 /var/www/html/sites/all/modules/contrib/redis/lib/Redis/Client.php(213): Redis_Client_Manager->getClient() #3 /var/www/html/sites/all/modules/contrib/redis/lib/Redis/Cache.php(178): Redis_Client::getClient() #4 /var/www/html/includes/cache.inc(32): Redis_Cache->__construct() #5 /var/www/html/includes/cache.inc(57): _cache_get_object() #6 /var/www/html/includes/module.inc(763): cache_get() #7 /var/www/html/includes/module.inc(963): module_implements() #8 /var/www/html/modules/system/system.module(2536): module_invoke_all() #9 /var/www/html/includes/theme.inc(798): _system_rebuild_theme_data() #10 /var/www/html/includes/theme.maintenance.inc( in /var/www/html/sites/all/modules/contrib/redis/lib/Redis/Client/PhpRedis.php on line 9