启动agent 日志报错信息如下
cd /opt/cm-5.16.0/log/cloudera-scm-agent
tail -n 200 cloudera-scm-agent.log

ProtocolError: <ProtocolError for 127.0.0.1/RPC2: 401 Unauthorized>
[13/Aug/2019 09:10:14 +0000] 8405 MainThread agent ERROR Failed to connect to newly launched supervisor. Agent will exit
[13/Aug/2019 09:10:14 +0000] 8405 MainThread agent INFO Stopping agent…
[13/Aug/2019 09:10:14 +0000] 8405 MainThread agent INFO No extant cgroups; unmounting any cgroup roots
[13/Aug/2019 09:10:14 +0000] 8405 Dummy-1 daemonize WARNING Stopping daemon.

试了网上很多说法 不行 已经不知道怎么办了
方法是：
$> ps -ef | grep supervisord
$> kill -9
sudo service cloudera-scm-agent restart

发现agent启动之后过一会就dead，也是这个方法解决