部署说明：
Hadoop HA和Hadoop集群不是一回事，Hadoop集群是由HDFS集群和Yarn（MapReduce）集群组成，是一个分布式存储HDFS和分布式计算框架集群构成，集群中Datanode和Nodemanager节点可以无限扩展。但是Hadoop集群必须依赖元数据节点Namenode和Yarn资源调度Resourcemanager节点，目前默认情况下这两类节点为单机运行，一旦元数据节点Namenode出现故障，将导致HDFS集群不可用，Resourcemanager节点出现故障，将导致MapReduce任务无法提交，导致分布式计算无法完成。
因此，基于上述原因，可以通过搭建Hadoop Namenode节点和Resourcemanager节点的备用节点来保障Hadoop集群的高可用，一旦Active的Namenode节点故障，Standby Namenode会快速无缝接管Namenode，同样如果Active的Resourcemanager节点出现故障，Standby的resourcemanager也可以快速接管Resourcemanager提供计算服务的资源调度。这就是我们本实验中涉及到的Hadoop HA，而非Hadoop集群。
一、安装规划
二、操作系统安装
操作系统版本：CentOS 6.4 X86_64
安装过程：略
三、JDK安装配置
安装版本：jdk1.7.0_65 32位
安装过程：
[root@hadoop-server01 bin]# mkdir -p /usr/local/apps
[root@hadoop-server01 bin]# ll /usr/local/apps/
total 4
drwxr-xr-x. 8 uucp 143 4096 Apr 10 2015 jdk1.7.0_80
[root@hadoop-server01 bin]# pwd
/usr/local/apps/jdk1.7.0_80/bin
[root@hadoop-server01 bin]#vi /etc/profile
export JAVA_HOME=/usr/local/apps/jdk1.7.0_80
export PATH=$PATH:$JAVA_HOME/bin
[root@hadoop-server01 bin]# source /etc/profile
四、基础环境配置
1、修改所有主机的/etc/hosts文件
192.168.1.31 hadoop-namenode01
192.168.1.32 hadoop-namenode02
192.168.1.41 hadoop-resourcemanager01
192.168.1.42 hadoop-resourcemanager02
192.168.1.51 hadoop-datanode01
192.168.1.52 hadoop-datanode02
192.168.1.53 hadoop-datanode03
192.168.1.61 hadoop-zknode01
192.168.1.62 hadoop-zknode02
192.168.1.63 hadoop-zknode03
192.168.1.71 hadoop-zkfcnode01
192.168.1.72 hadoop-zkfcnode02
2、关闭防火墙
service iptabels stop
chkconfig iptablels off
五、配置免密登录
1、要求所有的namenode及yarnnode能免密登录到所有服务器
2、配置示例
[root@hadoop-namenode02 apps]# ssh-keygen
[root@hadoop-namenode01 apps]# ssh-copy-id hadoop-namenode02
[root@hadoop-namenode01 apps]# ssh hadoop-namenode02
六、集群安装部署
1、部署zookeeper集群
（1）部署节点
192.168.1.61
192.168.1.62
192.168.1.63
（2）解压安装包并修改配置文件
[root@hadoop-zknode01 ~]# tar -xvf zookeeper-3.4.5.tar.gz -C /usr/local/apps/
[root@hadoop-zknode01 conf]# cd /usr/local/apps/zookeeper-3.4.5/conf
[root@hadoop-zknode01 conf]# mv zoo_sample.cfg zoo.cfg
[root@hadoop-zknode01 conf]# vi zoo.cfg
# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just
# example sakes.
dataDir=/usr/local/apps/zookeeper-3.4.5/data
# the port at which the clients will connect
clientPort=2181
#
# Be sure to read the maintenance section of the
# administrator guide before turning on autopurge.
#
# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
#
# The number of snapshots to retain in dataDir
#autopurge.snapRetainCount=3
# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1
server.1=hadoop-zknode01:2888:3888
server.2=hadoop-zknode02:2888:3888
server.3=hadoop-zknode03:2888:3888
（3）创建myid文件
[root@hadoop-zknode01 data]# cd /usr/local/apps/zookeeper-3.4.5/data
[root@hadoop-zknode01 data]# echo 1 > myid
（4）拷贝zk到其它节点并修改myid
[root@hadoop-zknode01 apps]# scp -r zookeeper-3.4.5/ hadoop-zknode02:/usr/local/apps/zookeeper-3.4.5/
[root@hadoop-zknode02 data]# echo 2 > myid
[root@hadoop-zknode01 apps]# scp -r zookeeper-3.4.5/ hadoop-zknode03:/usr/local/apps/zookeeper-3.4.5/
[root@hadoop-zknode03 data]# echo 3 > myid
（5）启动zk
[root@hadoop-zknode01 apps]# cd zookeeper-3.4.5/bin/
[root@hadoop-zknode01 bin]# ./zkServer.sh start
JMX enabled by default
Using config: /usr/local/apps/zookeeper-3.4.5/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
另外两个节点也启动zk
2、部署Hadoop集群
（1）安装节点
192.168.1.31
192.168.1.32
192.168.1.41
192.168.1.42
192.168.1.51
192.168.1.52
192.168.1.53
（2）解压安装包
[root@hadoop-namenode01 hadoop]# tar -xvf hadoop-2.4.1.tar.gz -C /usr/local/apps/
（3）修改hadoop-env.sh
cd /usr/local/apps/hadoop-2.4.1/etc/hadoop
# The java implementation to use.
export JAVA_HOME=/usr/local/apps/jdk1.7.0_65
# The jsvc implementation to use. Jsvc is required to run secure datanodes.
#export JSVC_HOME=${JSVC_HOME}
（4）修改core-site.xml
cd /usr/local/apps/hadoop-2.4.1/etc/hadoop
（5）修改hdfs-site.xml
sshfence
shell(/bin/true)
（6）修改mapred-site.xml
[root@hadoop-namenode01 hadoop]# mv mapred-site.xml.template mapred-site.xml
（7）修改yarn-site.xml
（8）修改slaves文件【namenode和yarn节点都要改，datanode和nodemanager都在相同服务器】
[root@hadoop-namenode01 hadoop]# vi slaves
hadoop-datanode01
hadoop-datanode02
hadoop-datanode03
（9）namenode01上hadoop分发到所有服务器
hadoop-namenode02
hadoop-resourcemanager01
hadoop-resourcemanager02
hadoop-datanode01
hadoop-datanode02
hadoop-datanode03
hadoop-zknode01
hadoop-zknode02
hadoop-zknode03
scp -r hadoop-2.4.1/ hadoop-resourcemanager01:/usr/local/apps/
.......
其它节点类似
（10）格式化HDFS
步骤1：启动zk【hadoop-zknode01,hadoop-zknode02,hadoop-zknode03】
确保zk已经启动，这里略
步骤2：启动journalnode【hadoop-zknode01,hadoop-zknode02,hadoop-zknode03】
[root@hadoop-zknode01 sbin]# cd /usr/local/apps/hadoop-2.4.1/sbin
[root@hadoop-zknode01 sbin]# ./hadoop-daemon.sh start journalnode
[root@hadoop-zknode02 sbin]# ./hadoop-daemon.sh start journalnode
[root@hadoop-zknode03 sbin]# ./hadoop-daemon.sh start journalnode
[root@hadoop-zknode03 sbin]# jps
4209 JournalNode
2997 QuorumPeerMain
步骤3：格式化HDFS
--在hadoop-namenode01上格式化
[root@hadoop-namenode01 bin]# cd /usr/local/apps/hadoop-2.4.1/bin
[root@hadoop-namenode01 bin]# ./hdfs namenode -format
--将hadoop-namenode01上的格式化数据拷贝到第二个namenode节点
[root@hadoop-namenode01 hadoop-2.4.1]# scp -r tmp/ hadoop-namenode02:/usr/local/apps/hadoop-2.4.1/
[root@hadoop-namenode01 current]# pwd
/usr/local/apps/hadoop-2.4.1/tmp/dfs/name/current
[root@hadoop-namenode01 current]# ll
total 16
-rw-r--r--. 1 root root 351 Jul 4 06:01 fsimage_0000000000000000000
-rw-r--r--. 1 root root 62 Jul 4 06:01 fsimage_0000000000000000000.md5
-rw-r--r--. 1 root root 2 Jul 4 06:01 seen_txid
-rw-r--r--. 1 root root 204 Jul 4 06:01 VERSION
步骤4：格式化ZKFC【只需要在任何一台naenode执行即可】
[root@hadoop-namenode01 bin]# pwd
/usr/local/apps/hadoop-2.4.1/bin
[root@hadoop-namenode01 bin]# ./hdfs zkfc -formatZK
18/07/04 06:12:16 INFO ha.ActiveStandbyElector: Session connected.
18/07/04 06:12:16 INFO ha.ActiveStandbyElector: Successfully created /hadoop-ha/ns1 in ZK.
--代表成功在zk里面创建了目录
18/07/04 06:12:16 INFO zookeeper.ZooKeeper: Session: 0x364639c799c0000 closed
18/07/04 06:12:16 INFO zookeeper.ClientCnxn: EventThread shut down
未完待续.....