#手动切换active与standby
sudo -u hdfs hdfs haadmin -failover nn2 nn1
#查看namenode状态
sudo -u hdfs hdfs haadmin -getServiceState nn1
#启动standby
sudo -u hdfs hadoop namenode -bootstrapStandby
#退出safe mode
sudo -u hdfs hadoop dfsadmin -safemode leave
#刷新hdfs节点
sudo hadoop dfsadmin -refreshNodes
#查看application日志
yarn logs -applicationId application_..._0010
#杀掉某个job
sudo -u yarn yarn application -kill application_..._0004
#刷新yarn节点
sudo yarn rmadmin -refreshNodes
#配置capacity scheduler acl不生效问题
需在queue的最顶层设置，即root.acl_submit_applications和root.acl_administer_queue。如果不设置root.acl_submit_applications和root.acl_administer_queue时，默认所有子queue都会有所有权限（可将此两个配置的值都设置为空格，取消所有用户的权限)。 If the given user/group has necessary ACLs on the given queue or one of the parent queues in the hierarchy they can submit applications（如果用户队列本身的权限，或者父队列的权限，那么用户就可以提交任务）
<property>
<name>yarn.scheduler.capacity.root.acl_submit_applications</name>
<value>USER1,USER2</value>
</property>
<property>
<name>yarn.scheduler.capacity.root.acl_administer_queue</name>
<value>USER1,USER2</value>
</property>
#查看用户acl权限
sudo -u USER mapred queue -showacls
#yarn node-label问题
'yarn.scheduler.capacity.<queue-path>.default-node-label-expression'的值只能有1个
#Kerberos初始化简要
krb5.conf
kadm5.acl
kdb5_util create -r LOUGUANSTAR.COM -s
shell% kadmin.local
kadmin.local: addprinc admin/admin@LOUGUANSTAR.COM
krb5kdc
kadmind
#列出所有principal
kadmin.local -q "list_principals"
kadmin.local -q "listprincs"
#添加principal
kadmin.local -q "addprinc -randkey test/test1.louguanstar.com@LOUGUANSTAR.COM"
#生成keytab
kadmin.local -q "ktadd -k impala116.keytab test/test1.louguanstar.com@LOUGUANSTAR.COM"
kadmin.local -q "ktadd -k impala163.keytab test/test1.louguanstar.com@LOUGUANSTAR.COM adc/test1.louguanstar.com@LOUGUANSTAR.COM"
#认证
kinit -kt yarn.keytab yarn/yarn.louguanstar.com@LOUGUANSTAR.COM
#删除principal
kadmin.local -q "delprinc spark_deploy@LENOVOMM2.COM"
#hdfs集群名更换后hive不能启动，需要修改metastore
UPDATE `SDS` SET `LOCATION` = replace(LOCATION, 'master:9000', 'louguanstar');
#hive查看建表语句
show create table dbname.tablename
#查看某个java进程的“日志”，需使用与java进程同一用户运行
jstack PID
#查看某java进程的jvm占用情况
jmap -heap PID
#查看某java进程GC状况
jstat -gcutil PID
#jvm申请内存问题，修改Linux内存管理方式
sysctl vm.overcommit_memory=1
/etc/sysctl.conf
vm.overcommit_memory = 1
#CDH使用的所有端口
cdh port https://www.cloudera.com/documentation/enterprise/5-2-x/topics/cdh_ig_ports_cdh5.html#topic_9_1
