数据库挂了，如何根据这些信息定位问题？

打开网站，发现网站报错，提示数据库连接失败。

打开阿里云，查看数据库服务状态，如下：

Welcome to aliyun Elastic Compute Service! [root@iZ94r80gdghZ ~]# ls [root@iZ94r80gdghZ ~]# service mariadb status Redirecting to /bin/systemctl status mariadb.service ● mariadb.service - MariaDB database server Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled) Drop-In: /etc/systemd/system/mariadb.service.d └─migrated-from-my.cnf-settings.conf Active: failed (Result: timeout) since 日 2016-04-10 19:32:47 CST; 2h 0min ago Process: 14771 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER (code=exited, status=0/SUCCESS) Main PID: 14771 (code=exited, status=0/SUCCESS) Status: "MariaDB server is down" 4 月 10 19:32:46 iZ94r80gdghZ mysqld[14771]: 2016-04-10 19:32:46 14005736395.... 4 月 10 19:32:46 iZ94r80gdghZ mysqld[14771]: Version: '10.1.13-MariaDB' soc...r 4 月 10 19:32:46 iZ94r80gdghZ mysqld[14771]: 2016-04-10 19:32:46 14005736351...s 4 月 10 19:32:46 iZ94r80gdghZ mysqld[14771]: 2016-04-10 19:32:46 14005658500.... 4 月 10 19:32:46 iZ94r80gdghZ mysqld[14771]: 2016-04-10 19:32:46 14005736351.... 4 月 10 19:32:47 iZ94r80gdghZ mysqld[14771]: 2016-04-10 19:32:47 14005736351...2 4 月 10 19:32:47 iZ94r80gdghZ mysqld[14771]: 2016-04-10 19:32:47 14005736351...e 4 月 10 19:32:47 iZ94r80gdghZ systemd[1]: Failed to start MariaDB database s.... 4 月 10 19:32:47 iZ94r80gdghZ systemd[1]: Unit mariadb.service entered faile.... 4 月 10 19:32:47 iZ94r80gdghZ systemd[1]: mariadb.service failed. 

那么根据如上提示怎么定位数据库出错原因呢？