Discuz! info: Can not connect to MySQL server

Time: 2018-10-21 4:29am
Script: /how-to-use-email-effectively-in-online-campaigning-t2082337.html

Error: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (11)
Errno.: 2002

Similar error report has beed dispatched to administrator before.