database error

Please can someone tell me what to do, I keep receiving 2 error messages;

Version 6.005

The First one is:

Cron <vivlinco@weedezyn> /usr/local/bin/php -q /home/vivlinco/public_html/periodic/tags.php‏

<div style="border:2px solid red;padding:4px;width:600px;margin:0px auto;">
<div style="text-align:center;background-color:red;color:white;font-weight:bold;">Error</div>
<div style="text-align:center;">Database connect failed</div>
</div>

Second :

Database error in Vivlin
Mysql error:
Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (11)
 
Debug backtrace:
Array
(
[1] => Array
(
[file] => /home/vivlinco/public_html/periodic/tags.php
[line] => 22
[args] => Array
(
[0] => /home/vivlinco/public_html/inc/db.inc.php
)
 
[function] => require_once
)
 
)