openstack dashboard报错及其解决办法

登陆页面报错： 出错啦！ 遇到异常情况，请刷新。如需帮助请联系管理员。

登陆页面登陆时，没有报错，但是无法跳转。

这两种情况的解决办法如下：
sed -i 's/^SESSION_ENGINE/#&/' /etc/openstack-dashboard/local_settings
echo "SESSION_ENGINE = 'django.contrib.sessions.backends.file'" >> /etc/openstack-dashboard/local_settings
systemctl restart httpd memcached && systemctl status httpd memcached
或者
sed -i 's/^SESSION_ENGINE/#&/' /etc/openstack-dashboard/local_settings
echo "SESSION_ENGINE = 'django.contrib.sessions.backends.cache'" >> /etc/openstack-dashboard/local_settings
systemctl restart httpd memcached && systemctl status httpd memcached