Warning: mysqli::mysqli(): (HY000/2002): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) in /home/payprintagg/system/database/mysqli.php on line 6

Fatal error: Uncaught exception 'ErrorException' with message 'Error: Could not make a database link (2002) Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)' in /home/payprintagg/system/database/mysqli.php:9 Stack trace: #0 /home/payprintagg/system/library/db.php(13): DBMySQLi->__construct('localhost', 'paadbu', 'vKT4PChw5jEKL6p...', 'paadbu') #1 /home/payprintagg/index.php(40): DB->__construct('mysqli', 'localhost', 'paadbu', 'vKT4PChw5jEKL6p...', 'paadbu') #2 {main} thrown in /home/payprintagg/system/database/mysqli.php on line 9