节点断开时间过长处理方法：
[root@slave1 ~]# /etc/init.d/cloudera-scm-agent status
cloudera-scm-agent dead but pid file exists
[root@slave1 ~]# service httpd status
httpd is stopped
[root@slave1 ~]# service httpd restart
Stopping httpd: [FAILED]
Starting httpd: [ OK ]
cloudera-scm-agent dead but pid file exists
[root@slave1 ~]# cd /var/run/
[root@slave1 run]# ls
[root@slave1 run]# rm -rf cloudera-scm-agent.pid
[root@slave1 run]# service cloudera-scm-agent status
cloudera-scm-agent is stopped
[root@slave1 run]# service cloudera-scm-agent start
Starting cloudera-scm-agent: [ OK ]
[root@slave1 run]# service cloudera-scm-agent status
cloudera-scm-agent (pid 6257) is running...
好了，重新启动各个应用进程，恢复正常