作为Hadoop初学者，自然要从安装入手。而hadoop的优势就是分布式，所以，也一定要安装分布式的系统。
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整体安装步骤，包括Zookeeper+HDFS+Hbase，为了文章简洁，我会分三篇blog记录我的安装步骤。
本文记录的是集群环境准备，zookeeper的安装步骤。
~~~~~~~~~~~环境准备部分~~~~~~~~~~~~~~~~~
IP部署规划（准备了三个虚拟机，操作系统是Centos6.7）
Zookeeper主机分配
192.168.67.101 c6701 192.168.67.102 c6702 192.168.67.103 c6703
HDFS主机分配
192.168.67.101 c6701 --Namenode+datanode 192.168.67.102 c6702 --datanode 192.168.67.103 c6703 --datanode
Hbase主机分配
192.168.67.101 c6701 --Master + region 192.168.67.102 c6702 --region 192.168.67.103 c6703 --region
1. 为了分别管理各个服务，我为每个服务，都单独创建了用户.
创建的用户有:
zk hdfs hbase
2. 为每一个用户创建ssh免密,并分发到全部节点，这样，我就只在C6701上执行命令，通过远程的方式安装C6702和C6703
ssh-keygen -t rsa -f ~/.ssh/id_rsa
拷贝密钥到全部节点即可（只有c6701访问02和03不需要密码，反向访问是需要密码的）
ssh-copy-id c6701 ssh-copy-id c6702 ssh-copy-id c6703
3. 强调一下，/etc/hosts 需要设置
[root@c6701 ~]# more /etc/hosts 192.168.67.101 c6701.org c6701 192.168.67.102 c6702.org c6702 192.168.67.103 c6703.org c6703
4. 下面在C6701执行，中间会调用ssh远程执行一些命令,验证ssh免密是否生效
ssh c6702 "cat /proc/cpuinfo" ssh c6702 "hostname"
5. 下载安装软件（内网地址）
cd /tmp/software wget http://192.21.104.48/deploy/jdk-8u144-linux-x64.tar.gz wget http://192.21.104.48/deploy/zookeeper-3.4.6.tar.gz wget http://192.21.104.48/deploy/hbase-1.1.3.tar.gz wget http://192.21.104.48/deploy/hadoop-2.6.0-EDH-0u2.tar.gz wget http://192.21.104.48/deploy/hadoop-2.7.1.tar.gz
6. 安装JDK，全部节点都要安装
#tar -xzvf jdk-8u144-linux-x64.tar.gz -C /usr/local
7. 添加下面信息到.bash_profile
export JAVA_HOME=/usr/local/jdk1.8.0_144 export JRE_HOME=/usr/local/jdk1.8.0_144/jre export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib:$CLASSPATH export PATH=$JAVA_HOME/bin:$PATH source /etc/profile
8. 检查版本信息
# java -version java version "1.8.0_144" Java(TM) SE Runtime Environment (build 1.8.0_144-b01) Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)
~~~~~~~~~~~zookeeper的安装部分~~~~~~~~~~~~~~~~~
1. 在C6701安装Zookeeper
useradd zk echo "zk:zk" | chpasswd su - zk mkdir zk tar -zxvf /tmp/software/zookeeper-3.4.6.tar.gz -C /home/zk/zk
~~~~~~~~~~~~~zoo.cfg的配置~~~~~~~~~~~~~~~ $ pwd /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg $ cat /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg |grep -v '^#' tickTime=2000 initLimit=10 syncLimit=5 dataDir=/data/zookeeper/data dataLogDir=/data/zookeeper/log clientPort=2181 autopurge.snapRetainCount=3 autopurge.purgeInterval=6 server.1=c6701:2888:3888 server.2=c6702:2888:3888 server.3=c6703:2888:3888 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2. 根据zoo.cfg创建data和log两个文件夹
#mkdir -p /data/zookeeper/data #mkdir -p /data/zookeeper/log #chown -R zk:zk /data/zookeeper #chown -R zk:zk /data/zookeeper/data #chown -R zk:zk /data/zookeeper/log
3.在zookeeper的目录中，创建上述两个文件夹。进入zkdata文件夹，创建文件myid，填入1。这里写入的1，是在zoo.cfg文本中的server.1中的1。当我们把所有文件都配置完毕，我们把hadoop1中yarn目录复制到其它机器中，我们在修改每台机器中对应的myid文本，hadoop2中的myid写入2。其余节点，安照上面配置，依此写入相应的数字。Zkdatalog文件夹，是为了指定zookeeper产生日志指定相应的路径。
# su - zk -c "echo 1 > /data/zookeeper/data/myid"
4. 添加环境变量,在/etc/profile目录中,将ZOOKEEPER_HOME/bin在原有的PATH后面加入":$ZOOKEEPER_HOME/bin"
关于环境变量修改/etc目录下的profile文件，也可以在根目录下的.bashrc目录下添加环境变量。这两者有什么区别：.bashrc是对当前目录用户的环境变量，profile文件是对所有用户都开放的目录。当系统加载文件中，先从profile找相应的路劲，如果没有会在.bashrc文件中找对应的环境变量路径。这两者大家稍至了解。
然后 source /etc/profile
5. 安装c6702的zookeeper
#ssh c6702 "useradd zk" #ssh c6702 "echo "zk:zk" | chpasswd"
为zk用户ssh免密
#ssh-copy-id zk@c6702
拷贝软件
#scp -r /tmp/software/hadoop-* root@c6702:/tmp/software #ssh c6702 "chmod 777 /tmp/software/*"
创建目录，解压软件
#ssh zk@c6702 "mkdir zk" #ssh zk@c6702 "tar -zxvf /tmp/software/zookeeper-3.4.6.tar.gz -C /home/zk/zk" #ssh zk@c6702 "ls -al zk" #ssh zk@c6702 "ls -al zk/zookeeper*" #ssh zk@c6702 "rm /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg" #scp -r /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg zk@c6702:/home/zk/zk/zookeeper-3.4.6/conf/. #ssh zk@c6702 "cat /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg |grep -v '^#'" 根据zoo.cfg创建目录 #ssh c6702 "mkdir -p /data/zookeeper/data" #ssh c6702 "chown -R zk:zk /data/zookeeper" #ssh c6702 "chown -R zk:zk /data/zookeeper/data" #ssh c6702 "mkdir -p /data/zookeeper/log" #ssh c6702 "chown -R zk:zk /data/zookeeper/log" 创建文件myid，填入2 ssh zk@c6702 "echo 2 > /data/zookeeper/data/myid"
6. 安装c6703的zookeeper
#ssh c6703 "useradd zk" #ssh c6703 "echo "zk:zk" | chpasswd"
为zk用户ssh免密
ssh-copy-id zk@c6703
拷贝软件
#scp -r /tmp/software/hadoop-* root@c6703:/tmp/software #ssh c6703 "chmod 777 /tmp/software/*"
创建目录，解压软件
#ssh zk@c6703 "mkdir zk" #ssh zk@c6703 "tar -zxvf /tmp/software/zookeeper-3.4.6.tar.gz -C /home/zk/zk" #ssh zk@c6703 "ls -al zk" #ssh zk@c6703 "ls -al zk/zookeeper*" #ssh zk@c6703 "rm /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg" #scp -r /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg zk@c6703:/home/zk/zk/zookeeper-3.4.6/conf/. #ssh zk@c6703 "cat /home/zk/zk/zookeeper-3.4.6/conf/zoo.cfg |grep -v '^#'"
根据zoo.cfg创建目录
#ssh c6703 "mkdir -p /data/zookeeper/data" #ssh c6703 "chown -R zk:zk /data/zookeeper" #ssh c6703 "chown -R zk:zk /data/zookeeper/data" #ssh c6703 "mkdir -p /data/zookeeper/log" #ssh c6703 "chown -R zk:zk /data/zookeeper/log" 创建文件myid，填入3 ssh zk@c6703 "echo 3 > /data/zookeeper/data/myid"
7. 启动ZK
/home/zk/zk/zookeeper-3.4.6/bin/zkServer.sh start /home/zk/zk/zookeeper-3.4.6/bin/zkServer.sh status
远程启动命令
ssh zk@c6702 "/home/zk/zk/zookeeper-3.4.6/bin/zkServer.sh\ start" ssh zk@c6703 "/home/zk/zk/zookeeper-3.4.6/bin/zkServer.sh\ start" ssh zk@c6702 "/home/zk/zk/zookeeper-3.4.6/bin/zkServer.sh\ status" ssh zk@c6703 "/home/zk/zk/zookeeper-3.4.6/bin/zkServer.sh\ status"
8. 没有全部启动三个ZK前的状态
[vagrant@c7003 bin]$ ./zkServer.sh status ZooKeeper JMX enabled by default Using config: /home/vagrant/zookeeper-3.4.10/bin/../conf/zoo.cfg Error contacting service. It is probably not running.
9. 需要将三个ZK全启动之后，才能选举出leader
$ ./zkServer.sh status ZooKeeper JMX enabled by default Using config: /home/vagrant/zookeeper-3.4.10/bin/../conf/zoo.cfg Mode: follower [vagrant@c7002 bin]$ ./zkServer.sh status ZooKeeper JMX enabled by default Using config: /home/vagrant/zookeeper-3.4.10/bin/../conf/zoo.cfg Mode: leader
=======2018.1.13更新==========
客户端连接方式
客户端是随机顺序的方式连接server的，无法指定，或者优先读哪个一个zookeeper server。
./zkCli.sh -server c6701:2181,c6702:2181,c6703:2181
输出如下：
第一次连接，连接到c6701上
[zookeeper@c6702 bin]$ /usr/local/hadoop/zookeeper-3.4.6/bin/zkCli.sh -server c6701:2181,c6702:2181,c6703:2181 Connecting to c6701:2181,c6702:2181,c6703:2181 ...... 2018-01-11 21:07:30,797 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=c6701:2181,c6702:2181,c6703:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@4b4bc1e Welcome to ZooKeeper! 2018-01-11 21:07:30,830 [myid:] - INFO [main-SendThread(c6701.python279.org:2181):ClientCnxn$SendThread@975] - Opening socket connection to server c6701.python279.org/192.168.67.101:2181. Will not attempt to authenticate using SASL (unknown error) JLine support is enabled 2018-01-11 21:07:30,873 [myid:] - INFO [main-SendThread(c6701.python279.org:2181):ClientCnxn$SendThread@852] - Socket connection established to c6701.python279.org/192.168.67.101:2181, initiating session 2018-01-11 21:07:30,916 [myid:] - INFO [main-SendThread(c6701.python279.org:2181):ClientCnxn$SendThread@1235] - Session establishment complete on server c6701.python279.org/192.168.67.101:2181, sessionid = 0x160e70285f70001, negotiated timeout = 30000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null
第二次连接，连接到c6702上
Connecting to c6701:2181,c6702:2181,c6703:2181 ...... 2018-01-11 21:10:18,442 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=c6701:2181,c6702:2181,c6703:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@4b4bc1e Welcome to ZooKeeper! 2018-01-11 21:10:18,489 [myid:] - INFO [main-SendThread(c6702.python279.org:2181):ClientCnxn$SendThread@975] - Opening socket connection to server c6702.python279.org/192.168.67.102:2181. Will not attempt to authenticate using SASL (unknown error) JLine support is enabled 2018-01-11 21:10:18,508 [myid:] - INFO [main-SendThread(c6702.python279.org:2181):ClientCnxn$SendThread@852] - Socket connection established to c6702.python279.org/192.168.67.102:2181, initiating session 2018-01-11 21:10:18,561 [myid:] - INFO [main-SendThread(c6702.python279.org:2181):ClientCnxn$SendThread@1235] - Session establishment complete on server c6702.python279.org/192.168.67.102:2181, sessionid = 0x260e70284650002, negotiated timeout = 30000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null
至此，基础环境部署完。并且zookeeper也安装完成。下面我们会在下一篇文章中，继续安装HDFS。
系列文章，请参考
Hadoop集群(一) Zookeeper搭建
Hadoop集群(二) HDFS搭建
Hadoop集群(三) Hbase搭建
Hadoop集群(四) Hadoop升级