Dashboard登录成功后 RuntimeError: Unable to create a new session key.

openstack按照官网docs部署horizon后，使用admin账号密码登录，但网页提示未知错误。

查看/var/log/httpd/error_log

提示这个：RuntimeError: Unable to create a new session key. It is likely that the cache is unavailable.

缓存有问题，在外国网站找到解决方案:

将 /etc/openstack-dashboard/local_settings 里的

SESSION_ENGINE = 'django.contrib.sessions.backends.cache'

改成

SESSION_ENGINE = 'django.contrib.sessions.backends.file'

重启httpd和memcached

成功进入Dashboard