Cloudera Manager Java Version

Cloudera Manager use /usr/lib/cmf/service/common/cloudera-config.sh to detect java version. The prefer order is JAVA 7 > JAVA 8 > JAVA 6 > OPENJAVA.
To override default JAVA_HOME setting, should set JAVA_HOME on each cluster hosts(Can be done easily on CM Web UI):
1) http://www.cloudera.com/documentation/enterprise/latest/topics/cm_ig_java_home_location.html#cmig_topic_16
This change affects all CDH processes and Cloudera Management Service roles in the cluster
2) /etc/default/bigtop-utils
This will change all default java processes.