Initialization Error

Array
(
    [callback] => Array
        (
            [0] => CRM_Core_Error
            [1] => simpleHandler
        )

    [code] => -24
    [message] => DB Error: connect failed
    [mode] => 16
    [debug_info] =>  [DB Error: connect failed]
    [type] => DB_Error
    [user_info] =>  [DB Error: connect failed]
    [to_string] => [db_error: message="DB Error: connect failed" code=-24 mode=callback callback=CRM_Core_Error::simpleHandler prefix="" info=" [DB Error: connect failed]"]
)

backTrace

/var/www/public/sites/all/modules/civicrm/CRM/Core/Error.php, backtrace, 235
, simpleHandler, 
/var/www/public/sites/all/modules/civicrm/packages/PEAR.php, call_user_func, 931
/var/www/public/sites/all/modules/civicrm/packages/DB.php, PEAR_Error, 968
/var/www/public/sites/all/modules/civicrm/packages/PEAR.php, DB_Error, 564
/var/www/public/sites/all/modules/civicrm/packages/DB/common.php, raiseError, 1903
/var/www/public/sites/all/modules/civicrm/packages/DB/mysql.php, raiseError, 256
/var/www/public/sites/all/modules/civicrm/packages/DB.php, connect, 558
/var/www/public/sites/all/modules/civicrm/packages/DB/DataObject.php, connect, 2291
/var/www/public/sites/all/modules/civicrm/packages/DB/DataObject.php, _connect, 2529
/var/www/public/sites/all/modules/civicrm/packages/DB/DataObject.php, _build_condition, 411
/var/www/public/sites/all/modules/civicrm/CRM/Core/BAO/Setting.php, find, 209
/var/www/public/sites/all/modules/civicrm/CRM/Core/Config.php, retrieve, 397
/var/www/public/sites/all/modules/civicrm/CRM/Core/Config.php, _initVariables, 202
/var/www/public/sites/all/modules/civicrm/drupal/civicrm.module, singleton, 272
/var/www/public/sites/all/modules/civicrm/drupal/modules/civicrm_group_roles/civicrm_group_roles.module, civicrm_initialize, 53
/var/www/public/modules/user/user.module, civicrm_group_roles_user, 32
/var/www/public/modules/user/user.module, user_module_invoke, 195
/var/www/public/modules/user/user.module, user_load, 1181
/var/www/public/includes/menu.inc, user_uid_optional_load, 412
/var/www/public/includes/menu.inc, _menu_load_objects, 659
/var/www/public/includes/menu.inc, _menu_link_translate, 1028
/var/www/public/includes/menu.inc, _menu_tree_check_access, 1017
/var/www/public/includes/menu.inc, menu_tree_check_access, 955
/var/www/public/includes/menu.inc, menu_tree_page_data, 1562
/var/www/public/includes/menu.inc, menu_set_active_trail, 1596
/var/www/public/includes/menu.inc, menu_get_active_trail, 1612
/var/www/public/includes/common.inc, menu_get_active_breadcrumb, 105
/var/www/public/includes/theme.inc, drupal_get_breadcrumb, 1884
, template_preprocess_page, 
/var/www/public/includes/theme.inc, call_user_func_array, 710
/var/www/public/index.php, theme, 35