SQLSTATE[HY000] [2002] Connection refused

FILE: /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Db/Driver.class.php 　LINE: 109

#0 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Db/Driver.class.php(109): E('SQLSTATE[HY000]...')
#1 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Db/Driver.class.php(1075): Think\Db\Driver->connect()
#2 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Db/Driver/Mysql.class.php(47): Think\Db\Driver->initConnect(true)
#3 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Model.class.php(134): Think\Db\Driver\Mysql->getFields('li_city')
#4 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Model.class.php(122): Think\Model->flush()
#5 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Model.class.php(1454): Think\Model->_checkTableInfo()
#6 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Model.class.php(97): Think\Model->db(0, '', true)
#7 /www/web/yueshengjia/public_html/ThinkPHP/Common/functions.php(621): Think\Model->__construct('City', '', '')
#8 /www/web/yueshengjia/public_html/Application/Common/Controller/HomeController.class.php(72): M('City')
#9 /www/web/yueshengjia/public_html/Application/Common/Controller/HomeController.class.php(41): Common\Controller\HomeController->setcity()
#10 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Controller.class.php(41): Common\Controller\HomeController->_initialize()
#11 /www/web/yueshengjia/public_html/ThinkPHP/Common/functions.php(681): Think\Controller->__construct()
#12 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/App.class.php(89): controller('Index', '')
#13 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/App.class.php(204): Think\App::exec()
#14 /www/web/yueshengjia/public_html/ThinkPHP/Library/Think/Think.class.php(120): Think\App::run()
#15 /www/web/yueshengjia/public_html/ThinkPHP/ThinkPHP.php(98): Think\Think::start()
#16 /www/web/yueshengjia/public_html/index.php(27): require('/www/web/yueshe...')
#17 {main}