celery突然连接不上rabbitmq server，结果找半天发现是rabbitmq卡的不行。。。
rabbitmq 设置web管理，添加用户
rabbitmqctl list_queues | grep notifications
rabbitmq-plugins enable rabbitmq_management
rabbitmqctl add_user mustang mustang
rabbitmqctl set_user_tags mustang administrator
rabbitmqctl set_permissions -p "/" mustang ".*" ".*" ".*"
测试磁盘速度
dd if=/dev/zero of=/tmp/output.img bs=8k count=256k;rm -rf /tmp/output.img
rabbitmqctl list_queues | grep notifications