组网说明：
hadoop1.localdomain 192.168.11.81（namenode）
hadoop2.localdomain 192.168.11.82（namenode）
hadoop3.localdomain 192.168.11.83(datanode)
hadoop4.localdomain 192.168.11.84(datanode)
hadoop5.localdomain 192.168.11.85(datanode)
第一步：卸载openjdk
rpm -qa |grep java
#查看已经安装的与java相关的包
rpm -e java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64
rpm -e --nodeps java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64
rpm -e tzdata-java-2013g-1.el6.noarch
#################################################################
第二步：禁用IPV6
echo net.ipv6.conf.all.disable_ipv6=1 >>/etc/sysctl.conf
echo "alias net-pf-10 off" >>/etc/modprobe.d/dist.conf
echo "alias ipv6 off" >>/etc/modprobe.d/dist.conf
reboot
##########################################################
第三步：解压hadoop压缩包
把压缩包导入到/usr目录
cd /usr
tar -zxvf hadoop--642.4.0.tar.gz
把目录重命名为hadoop
mv hadoop--642.4.0 hadoop
安装jdk1.7,把安装包导入到/usr目录
cd /usr
rpm -ivh jdk-7u71-linux-x64.rpm
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第四步：设置JAVA&HADOOP环境变量
vi /etc/profile
#set java environment
export JAVA_HOME=/usr/java/jdk1.7.0_71/
export HADOOP_PREFIX=/usr/hadoop/
export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$PATH:$JAVA_HOME/bin
#set hadoop environment
export HADOOP_HOME=/usr/hadoop/
export PATH=$HADOOP_HOME/bin:$PATH:$HADOOP_HOME/sbin/
#使配置生效
source /etc/profile
或者重启服务器，也会重新加载该配置
################################################
第五步：创建hdfs需要的目录
mkdir -p /home/hadoop/dfs/name
mkdir -p /home/hadoop/dfs/data
##############################
第六步：java enviromnet追加到hadoop环境变量配置文件中
echo export JAVA_HOME=/usr/java/jdk1.7.0_71/ >>/usr/hadoop/etc/hadoop/hadoop-env.sh
echo export JAVA_HOME=/usr/java/jdk1.7.0_71/ >>/usr/hadoop/etc/hadoop/yarn-env.sh
####################################################################################
第七步：免ssh key,可以只在namenode上，因为一般情况下，由namenode控制datanode
略，查看相关配置手册
####################
第八步：编辑datanode配置文件，只在namenode上
[root@hadoop1 hadoop]# pwd
/usr/hadoop/etc/hadoop
[root@hadoop1 hadoop]# more slaves
hadoop3.localdomain
hadoop4.localdomain
hadoop5.localdomain
########################################
[root@hadoop1 hadoop]# more core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://hadoop1.localdomain:8020</value>
</property>
#
# <property>
# <name>fs.defaultFS</name>
# <value>viewfs://nsX</value>
# </property>
#
<property>
<name>io.file.buffer.size</name>
<value>131072</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>file:/home/hadoop/tmp</value>
</property>
<property>
<name>hadoop.proxyuser.hadoop.hosts</name>
<value>*</value>
</property>
<property>
<name>hadoop.proxyuser.hadoop.groups</name>
<value>*</value>
</property>
</configuration>
###########################################
hdfs-site.xml
<property>
<name>dfs.namenode.name.dir</name>
<value>/home/hadoop/dfs/name</value>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>/home/hadoop/dfs/data</value>
</property>
<property>
<name>dfs.replication</name>
<value>3</value>
</property>
<property>
<name>dfs.webhdfs.enabled</name>
<value>true</value>
</property>
###############################
<property>
<name>dfs.federation.nameservices</name>
<value>ns1,ns2</value>
</property>
<property>
<name>dfs.namenode.rpc-address.ns1</name>
<value>hadoop1.localdomain:8020</value>
</property>
<property>
<name>dfs.namenode.http-address.ns1</name>
<value>hadoop1.localdomain:50070</value>
</property>
<property>
<name>dfs.namenode.secondaryhttp-address.ns1</name>
<value>hadoop1.localdomain:50080</value>
</property>
<property>
<name>dfs.namenode.rpc-address.ns2</name>
<value>hadoop2.localdomain:8020</value>
</property>
<property>
<name>dfs.namenode.http-address.ns2</name>
<value>hadoop2.localdomain:50070</value>
</property>
<property>
<name>dfs.namenode.secondaryhttp-address.ns2</name>
<value>hadoop2.localdomain:50080</value>
</property>
#################################
mapred-site.xml
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapreduce.jobhistory.address</name>
<value>hadoop1.localdomain:10020</value>
</property>
<property>
<name>mapreduce.jobhistory.webapp.address</name>
<value>hadoop1.localdomain:19888</value>
</property>
###########################
yarn-site.xml
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
<property>
<name>yarn.resourcemanager.address</name>
<value>hadoop1.localdomain:8032</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>hadoop1.localdomain:8030</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address</name>
<value>hadoop1.localdomain:8031</value>
</property>
<property>
<name>yarn.resourcemanager.admin.address</name>
<value>hadoop1.localdomain:8033</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address</name>
<value>hadoop1.localdomain:8088</value>
</property>
#############################
1、在hadoop1上，把hadoop所在文件夹拷贝到其他节点上，不用更改配置
scp /usr/hadoop hadoop2:/usr/
scp /usr/hadoop hadoop3:/usr/
scp /usr/hadoop hadoop4:/usr/
scp /usr/hadoop hadoop5:/usr/
2、格式化namenode，两个namenode都要格式化，切clusterid
hdfs namenode -format -clusterId MyHadoopCluster
MyHadoopCluster是以字符串的形式
3、每次格式化namenode之前，要删除缓存
rm -rf /home/hadoop/dfs/data/*
rm -rf /home/hadoop/dfs/name/*
4、
开启
start-all.sh
关闭
stop-all.sh
访问方式：
http://hadoop1.localdomain:50070/dfsclusterhealth.jsp
http://hadoop1.localdomain:50070/dfshealth.jsp
http://hadoop1.localdomain:50070/dfshealth.html#tab-overview
http://hadoop1.localdomain:8088/cluster/nodes
参考阅读：
http://hadoop.apache.org/docs/r2.2.0/hadoop-project-dist/hadoop-hdfs/Federation.html
http://zh.hortonworks.com/blog/an-introduction-to-hdfs-federation/
