登录界面空白

你好，安装禅道后登录界面显示空白

报错日志显示

20:40:17 ERROR: SQLSTATE[HY000] [2002] Connection refused in framework/base/router.class.php on line 2739, last called by framework/base/router.class.php on line 2686 through function connectByPDO.
in /opt/zbox/app/zentao/framework/base/router.class.php on line 2797 when visiting