CDH6.2.1安装时cloudera-scm-server无法启动出现JDK版本不兼容问题

如题，今天在测试环境安装CDH6.2.1时，cloudera-scm-server无法启动，查看日志文件/var/log/cloudera-scm-server/cloudera-scm-server.out，发现以下输出：

+======================================================================+
|      Error: Unable to find a compatible version of Java on this host,|
|             either because JAVA_HOME has not been set or because a   |
|             compatible version of Java is not installed.             |
+----------------------------------------------------------------------+
| Please install either:                                               |
| - a supported version of the Oracle JDK from the Oracle Java web     |
|   site:                                                              |
|   > http://www.oracle.com/technetwork/java/javase/index.html <       |
| OR                                                                   |
| - a supported version of the OpenJDK from your OS vendor.  Help for  |
|   some OSes are available at:                                        |
|   > http://openjdk.java.net/install/ <                               |
|                                                                      |
| Cloudera Manager requires Oracle JDK or OpenJDK 1.8 or later.        |
| NOTE: Cloudera Manager will find the Oracle JDK when starting,       |
|       regardless of whether you installed the JDK using a binary     |
|       installer or the RPM-based installer.                          |
+======================================================================+

仔细检查本机的jdk版本为1.8.0_181

[root@hadoop11-test1-rgtj1-tj1 x86_64]# java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

按照cdh官网提示，也是建议的采用这个版本才是啊

https://docs.cloudera.com/documentation/enterprise/6/release-notes/topics/rg_java_requirements.html#java_requirements

仔细看日志：

注意:Cloudera Manager会在启动时找到Oracle JDK 无论您是否使用二进制|安装JDK ，安装程序或基于rpm的安装程序。

NOTE: Cloudera Manager will find the Oracle JDK when starting,       |
|       regardless of whether you installed the JDK using a binary     |
|       installer or the RPM-based installer.

于是重新安装jdk，采用从cdh官网提供的oracle 的jdk版本

https://archive.cloudera.com/cm6/6.2.1/redhat7/yum/RPMS/x86_64/oracle-j2sdk1.8-1.8.0+update181-1.x86_64.rpm

rpm -ivh  oracle-j2sdk1.8-1.8.0+update181-1.x86_64.rpm

再次启动cm，问题解决。

service cloudera-scm-server start