3 hadoop集群环境搭建

http://archive.apache.org/dist/

1目前为止

然后为了避免路由网络传输出现问题---->集群机器关闭防火墙

清空系统防火墙
iptables -L
iptables -F

保存防火墙配置
service iptables save

    如果上述命令执行失败报出：The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use     systemctl.

    解决方法：
    systemctl stop firewalld 关闭防火墙
    yum install iptables-services 安装或更新服务
    再使用systemctl enable iptables 启动iptables
    最后 systemctl start iptables 打开iptables

    再执行service iptables save

查看防火墙状态

    firewall-cmd --state

停止firewall

    systemctl stop firewalld.service

禁止firewall开机启动

    systemctl disable firewalld.service

临时关闭内核防火墙

    setenforce 0
    getenforce

永久关闭内核防火墙

    vim /etc/selinux/config
    SELINUX=disabled

2解压

通过命令

    tar -zxvf hadoop-2.6.5.tar.gz

3修改主机名

Execute in Master

vim /etc/sysconfig/network
```
  NETWORKING=yes
  HOSTNAME=master
```

Execute in Slave1

vim /etc/sysconfig/network
```
  NETWORKING=yes
  HOSTNAME=slave1
```

Execute in Slave2

vim /etc/sysconfig/network
```
  NETWORKING=yes
  HOSTNAME=slave2
```

使用reboot命令重启服务器,即可看到hostname被修改了,(还有使用hostname newhostname命令可以临时命名)

5查看及修改IP地址

vim /etc/sysconfig/network-scripts/ifcfg-ens33

6修改主机文件

Execute in Master、Slave1、Slave2

vim /etc/hosts

192.168.192.10 master
192.168.192.11 slave1
192.168.192.12 slave2

使用ping命令检测

7SSH互信配置

Execute in Master、Slave1、Slave2

生成密钥对（公钥和私钥）

    ssh-keygen -t rsa

三次回车生成密钥

cat /root/.ssh/id_rsa.pub
可以查看到

Execute in Maste

将密匙输出到/root/.ssh/authorized_keys

    cat /root/.ssh/id_rsa.pub > /root/.ssh/authorized_keys
    chmod 600 /root/.ssh/authorized_keys

追加密钥到Master

    ssh slave1 cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys
    ssh slave2 cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys

注意：这是需要操作及密码验证，追加完后查看一下该文件

cat /root/.ssh/authorized_keys

复制密钥到从节点

    scp /root/.ssh/authorized_keys root@slave1:/root/.ssh/authorized_keys
    scp /root/.ssh/authorized_keys root@slave2:/root/.ssh/authorized_keys

然后在使用上面的命令查看从节点是否有了该文件

8 修改hadoop配置文件(这时候有主从差别咯，先看master配置)

master

cd hadoop-2.6.5/etc/hadoop/
vim hadoop-env.sh

export JAVA_HOME=/usr/local/src/jdk1.8.0_191

vim yarn-env.sh

export JAVA_HOME=/usr/local/src/jdk1.8.0_191

vim masters

master

vim slaves

slave1
slave2

vim core-site.xml

<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://master:9000</value>
    </property>
    <property>
        <name>hadoop.tmp.dir</name>
        <value>file:/usr/local/src/hadoop-2.6.5/tmp</value>
    </property>
</configuration>

vim hdfs-site.xml

<configuration>
    <property>
        <name>dfs.namenode.secondary.http-address</name>
        <value>master:9001</value>
    </property>
    <property>
        <name>dfs.namenode.name.dir</name>
        <value>file:/usr/local/src/hadoop-2.6.5/dfs/name</value>
    </property>
    <property>
        <name>dfs.datanode.data.dir</name>
        <value>file:/usr/local/src/hadoop-2.6.5/dfs/data</value>
    </property>
    <property>
        <name>dfs.replication</name>
        <value>3</value>
    </property>
</configuration>

vim mapred-site.xml.template

<configuration>
    <property>
        <name>mapreduce.framework.name</name>
        <value>yarn</value>
    </property>
</configuration>

复制一下

cp mapred-site.xml.template mapred-site.xml
vim yarn-site.xml

<configuration>
<!-- Site specific YARN configuration properties -->
    <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>master:8032</value>
    </property>
    <property>
        <name>yarn.resourcemanager.scheduler.address</name>
        <value>master:8030</value>
    </property>
    <property>
        <name>yarn.resourcemanager.resource-tracker.address</name>
        <value>master:8035</value>
    </property>
    <property>
        <name>yarn.resourcemanager.admin.address</name>
        <value>master:8033</value>
    </property>
    <property>
        <name>yarn.resourcemanager.webapp.address</name>
        <value>master:8088</value>
    </property>
</configuration>

创建临时目录和文件目录
- mkdir /usr/local/src/hadoop-2.6.5/tmp
- mkdir -p /usr/local/src/hadoop-2.6.5/dfs/name
- mkdir -p /usr/local/src/hadoop-2.6.5/dfs/data
配置环境变量

Master、Slave1、Slave2
vim ~/.bashrc

HADOOP_HOME=/usr/local/src/hadoop-2.6.5
export PATH=$PATH:$HADOOP_HOME/bin

刷新环境变量
```
  source ~/.bashrc
```

拷贝安装包

Master

  scp -r /usr/local/src/hadoop-2.6.5 root@slave1:/usr/local/src/hadoop-2.6.5 
  scp -r /usr/local/src/hadoop-2.6.5 root@slave2:/usr/local/src/hadoop-2.6.5