Crontab is inconsistent with system time
After migrating the online database to the virtual machine, the operation and maintenance staff did not change the time.
After the time modification is completed later, it will also be modified on the database, but the backup time of the scheduled task is not performed at 4: 00 in the morning, but at 12: 10 noon.
The reason is that crontab needs to be restarted after changing the time.
Modify database time
Set time_zone ='+ 08 00'
Set global time_zone ='+ 08 00'
Flush privielges
Restart crontab
/ etc/init.d/crond restart
