CDH6出现Role not started due to unhealthy host的异常
今天重启CDH集群时出现了一个错误：Completed only 2/3 steps. First failure: Role not started due to unhealthy host slave5.，其中一台zookeeper无法启动，如下图所示：
异常的原因是CDH启动顺序出错，应该是这台机器先启动了cloudera-scm-agent，然后又去启动了cloudera-scm-server。正确的顺序应该是先启动cloudera-scm-server,再启动cloudera-scm-agent。
解决办法：
停止所有服务
先停止cloudera-scm-server
1 | service cloudera-scm-server stop |
在停止其他机器的cloudera-scm-agent
1 | service cloudera-scm-agent stop |
启动服务
先启动cloudera-scm-server
1 | service cloudera-scm-server start |
再启动cloudera-scm-agent
1 | service cloudera-scm-agent start |
启动完成服务正常
参考资料：