Trying to resolve error messages

[2012-08-02 07:31:47] (ERROR @ /index.php) Error HY000 executing statement: 
Array
(
    [0] => HY000
    [1] => 2006
    [2] => MySQL server has gone away
)

2012-08-01 10:22:51] (ERROR in xPDOConnection::connect @ /************httpdocs/core/xpdo/xpdo.class.php : 2997) SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[2012-08-01 10:22:51] (ERROR in xPDOConnection::connect @ /************/httpdocs/core/xpdo/xpdo.class.php : 2997) SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[2012-08-01 10:22:51] (ERROR @ /index.php) Error preparing statement for query: SELECT `modSession`.`id` AS `modSession_id`, `modSession`.`access` AS `modSession_access`, `modSession`.`data` AS `modSession_data` FROM `modx_session` AS `modSession` WHERE `modSession`.`id` = ?  - 
[2012-08-01 10:22:51] (ERROR in xPDOConnection::connect @ /************/httpdocs/core/xpdo/xpdo.class.php : 2997) SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[2012-08-01 10:22:51] (ERROR in xPDOConnection::connect @ /************/httpdocs/core/xpdo/xpdo.class.php : 2997) SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[2012-08-01 10:22:51] (ERROR @ /index.php) Error preparing statement for query: SELECT `modSession`.`id` AS `modSession_id`, `modSession`.`access` AS `modSession_access`, `modSession`.`data` AS `modSession_data` FROM `modx_session` AS `modSession` WHERE `modSession`.`id` = ?  - 
[2012-08-01 10:22:51] (ERROR @ /index.php) Error HY000 executing query: SELECT `modSnippet`.`id` AS `modSnippet_id`, `modSnippet`.`source` AS `modSnippet_source`, `modSnippet`.`property_preprocess` AS `modSnippet_property_preprocess`, `modSnippet`.`name` AS `modSnippet_name`, `modSnippet`.`description` AS `modSnippet_description`, `modSnippet`.`editor_type` AS `modSnippet_editor_type`, `modSnippet`.`category` AS `modSnippet_category`, `modSnippet`.`cache_type` AS `modSnippet_cache_type`, `modSnippet`.`snippet` AS `modSnippet_snippet`, `modSnippet`.`locked` AS `modSnippet_locked`, `modSnippet`.`properties` AS `modSnippet_properties`, `modSnippet`.`moduleguid` AS `modSnippet_moduleguid`, `modSnippet`.`static` AS `modSnippet_static`, `modSnippet`.`static_file` AS `modSnippet_static_file`, `Source`.`id` AS `Source_id`, `Source`.`name

AND

[2012-08-02 10:50:37] (ERROR @ /connectors/system/log.php) Could not load class: unknown from mysql.unknown.
[2012-08-02 10:50:37] (ERROR @ /connectors/system/log.php) unknown::load() is not a valid static method.