一 完全分布式集群(單點）

Hadoop官方地址：http://hadoop.apache.org/

1 準備3臺客戶機

1.1防火墻,靜態IP,主機名

關閉防火墻，設置靜態IP，主機名此處略，參考 Linux之CentOS7.5安裝及克隆

1.2 修改host文件

我們希望三個主機之間都能夠使用主機名稱的方式相互訪問而不是IP，我們需要在hosts中配置其他主機的host。因此我們在主機的/etc/hosts下均進行如下配置：

[[email protected] ~]# vi /etc/hosts
配置主機host
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.100.21 hadoop0
192.168.100.22 hadoop1
192.168.100.23 hadoop2
將配置發送到其他主機（同時在其他主機上配置）
[[email protected] ~]# scp -r /etc/hosts [email protected]:/etc/
[[email protected] ~]# scp -r /etc/hosts [email protected]:/etc/
測試
[[email protected] ~]# ping hadoop0
[[email protected] ~]# ping hadoop1
[[email protected] ~]# ping hadoop2

1.3 添加用戶賬號

在所有的主機下均建立一個賬號hadoop用來運行hadoop ，並將其添加至sudoers中
[[email protected] ~]# useradd hadoop    #添加用戶通過手動輸入修改密碼
[[email protected] ~]# passwd  hadoop    #更改用戶 hadoop 的密碼
hadoop  #密碼
#passwd： 所有的身份驗證令牌已經成功更新。
設置hadoop用戶具有root權限  修改 /etc/sudoers 文件，找到下面一行，在root下面添加一行，如下所示：
[[email protected] ~]# vim /etc/sudoers
 

#找到這裏
## Allow root to run any commands anywhere
root    ALL=(ALL)     ALL
hadoop   ALL=(ALL)     ALL

修改完畢  ：wq！ 保存退出，現在可以用hadoop帳號登錄，然後用命令 su hadoop ，切換用戶即可獲得root權限進行操作。　

1.4 /目錄下創建文件夾

1）在root用戶下創建hadoop文件夾
[[email protected] /]# cd /
[[email protected] /]# mkdir hadoop
2）修改hadoop文件夾的所有者
[[email protected] opt]# chown -R hadoop:hadoop /hadoop
3）查看hadoop文件夾的所有者
[[email protected] /]# ll

drwxr-xr-x. 4 hadoop hadoop 46 May 10 16:56 hadoop

2 安裝配置jdk1.8

[[email protected] ~]# rpm -qa|grep java   #查詢是否安裝java軟件：
這裏使用官網下載好的tar包傳到服務器  /hadoop 下 
[[email protected] hadoop]# tar -zxvf  jdk-8u181-linux-x64.tar.gz 
[[email protected] hadoop]# mv jdk1.8.0_181 jdk1.8
設置JAVA_HOME

[[email protected] hadoop]# vim /etc/profile

#在文件末尾添加

#JAVA
export JAVA_HOME=/hadoop/jdk1.8
export JRE_HOME=/hadoop/jdk1.8/jre
export CLASSPATH=.:$CLASSPATH:$JAVA_HOME/lib:$JRE_HOME/lib
export PATH=$PATH:$JAVA_HOME/bin:$JAVA_HOME/sbin

[[email protected] hadoop]# source /etc/profile  #重啟配置文件生效
#檢查是否配置成功

[[email protected] /]$ java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

3 安裝hadoop集群

3.1 集群部署規劃

3.2 設置SSH免密鑰

關於ssh免密碼的設置，要求每兩臺主機之間設置免密碼，自己的主機與自己的主機之間也要求設置免密碼。 這項操作可以在hadoop用戶下執行，執行完畢公鑰在/home/hadoop/.ssh/id_rsa.pub

[[email protected] ~]# ssh-keygen -t rsa
[[email protected] ~]# ssh-copy-id hadoop0
[[email protected] ~]# ssh-copy-id hadoop1
[[email protected] ~]# ssh-copy-id hadoop2

node1與node2為namenode節點要相互免秘鑰 HDFS的HA

[[email protected] ~]# ssh-keygen -t rsa
[[email protected] ~]# ssh-copy-id hadoop1
[[email protected] ~]# ssh-copy-id hadoop0
[[email protected] ~]# ssh-copy-id hadoop2

node2與node3為yarn節點要相互免秘鑰 YARN的HA

[[email protected] ~]# ssh-keygen -t rsa
[[email protected] ~]# ssh-copy-id hadoop2
[[email protected] ~]# ssh-copy-id hadoop0
[[email protected] ~]# ssh-copy-id hadoop1　

3.3 解壓安裝hadoop

[[email protected] hadoop]# tar -zxvf hadoop-2.7.7.tar.gz

4 配置hadoop集群

註意：配置文件在hadoop2.7.7/etc/hadoop/下

4.1 修改core-site.xml

[[email protected] hadoop]$ vi core-site.xml
<configuration>

<!-- 指定HDFS中NameNode的地址 -->
<property>
<name>fs.defaultFS</name>
<value>hdfs://hadoop0:9000</value>
</property>
<!-- 指定hadoop運行時產生文件的存儲目錄,註意tmp目錄需要創建 -->
<property>
<name>hadoop.tmp.dir</name>
<value>/hadoop/hadoop-2.7.7/tmp</value>
</property>

</configuration>

4.2 修改hadoop-env.sh

[[email protected]  hadoop]$ vi hadoop-env.sh 
修改 export JAVA_HOME=/hadoop/jdk1.8

4.3 修改hdfs-site.xml

[[email protected]  hadoop]$ vi hdfs-site.xml
<configuration>

<!-- 設置dfs副本數，不設置默認是3個 -->
<property>
<name>dfs.replication</name>
<value>2</value>
</property>

<!-- 設置namenode數據存放路徑 -->
<property>
<name>dfs.name.dir</name>

<value>/hadoop/hadoop-2.7.7/dfs/name</value>

</property>

<!-- 設置datanode數據存放路徑 -->
<property>

<name>dfs.data.dir</name>

<value>/hadoop/hadoop-2.7.7/dfs/data</value>

</property>
<!-- 設置secondname的端口 -->
<property>
<name>dfs.namenode.secondary.http-address</name>
<value>hadoop1:50090</value>
</property>

</configuration>

4.4 修改slaves

[[email protected]  hadoop]$ vi slaves
hadoop0
hadoop1
hadoop2

4.5 修改mapred-site.xml

[[email protected] hadoop]# mv mapred-site.xml.template mapred-site.xml
[[email protected] hadoop]$ vi mapred-site.xml
<configuration>
<!-- 指定mr運行在yarn上 -->
    <property>
     <name>mapreduce.framework.name</name>
     <value>yarn</value>
    </property>
</configuration>

4.6 修改yarn-site.xml

[[email protected] hadoop]$ vi yarn-site.xml
<configuration>
<!-- reducer獲取數據的方式 -->
     <property>
        <name>yarn.nodemanager.aux-services</name>
        <value>mapreduce_shuffle</value>
     </property>
<!-- 指定YARN的ResourceManager的地址 -->
     <property>
        <name>yarn.resourcemanager.hostname</name>
        <value>hadoop0</value>
     </property>
</configuration>

4.9 分發hadoop到節點

[[email protected] /]# scp -r hadoop/ [email protected]:$PWD
[[email protected] /]# scp -r hadoop/ [email protected]:$PWD

4.10 配置環境變量

[[email protected] ~]$ sudo vim /etc/profile
末尾追加
export  HADOOP_HOME=/hadoop/hadoop-2.7.7
export  PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin
編譯生效  source  /etc/profile

5 啟動驗證集群

5.1 啟動集群

如果集群是第一次啟動，需要格式化namenode

[[email protected] hadoop-2.7.7]$ hdfs namenode -format　

啟動Hdfs：

[[email protected] ~]# start-dfs.sh

Starting namenodes on [hadoop0]
hadoop0: starting namenode, logging to /hadoop/hadoop-2.7.7/logs/hadoop-hadoop-namenode-hadoop0.out
hadoop0: starting datanode, logging to /hadoop/hadoop-2.7.7/logs/hadoop-hadoop-datanode-hadoop0.out
hadoop2: starting datanode, logging to /hadoop/hadoop-2.7.7/logs/hadoop-hadoop-datanode-hadoop2.out
hadoop1: starting datanode, logging to /hadoop/hadoop-2.7.7/logs/hadoop-hadoop-datanode-hadoop1.out
Starting secondary namenodes [hadoop1]
hadoop1: starting secondarynamenode, logging to /hadoop/hadoop-2.7.7/logs/hadoop-hadoop-secondarynamenode-hadoop1.out

啟動Yarn：　註意：Namenode和ResourceManger如果不是同一臺機器，不能在NameNode上啟動 yarn，應該在ResouceManager所在的機器上啟動yarn。

[[email protected] ~]# start-yarn.sh

starting yarn daemons
starting resourcemanager, logging to /hadoop/hadoop-2.7.7/logs/yarn-hadoop-resourcemanager-hadoop0.out
hadoop2: starting nodemanager, logging to /hadoop/hadoop-2.7.7/logs/yarn-hadoop-nodemanager-hadoop2.out
hadoop1: starting nodemanager, logging to /hadoop/hadoop-2.7.7/logs/yarn-hadoop-nodemanager-hadoop1.out
hadoop0: starting nodemanager, logging to /hadoop/hadoop-2.7.7/logs/yarn-hadoop-nodemanager-hadoop0.out

jps查看進程

[[email protected] hadoop-2.7.7]$ jps
2162 NodeManager
2058 ResourceManager
2458 Jps
1692 NameNode
1820 DataNode

[[email protected] hadoop]$ jps
1650 Jps
1379 DataNode
1478 SecondaryNameNode
1549 NodeManager

[[email protected] hadoop]$ jps
1506 DataNode
1611 NodeManager
1711 Jps

5.2 Hadoop啟動停止方式

1）各個服務組件逐一啟動
分別啟動hdfs組件： hadoop-daemon.sh  start|stop  namenode|datanode|secondarynamenode
   啟動yarn：     yarn-daemon.sh    start|stop  resourcemanager|nodemanager

2）各個模塊分開啟動（配置ssh是前提）常用
start|stop-dfs.sh     start|stop-yarn.sh

3）全部啟動（不建議使用）
start|stop-all.sh

5.3 集群時間同步

是否安裝ntp

[[email protected] hadoop-2.7.7]$ ntp

bash: ntp: command not found

[[email protected] hadoop-2.7.7]$ sudo yum install ntp #安裝ntp

[[email protected] hadoop-2.7.7]$ sudo ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime #linux的時區設置為中國上海時區

[[email protected] hadoop-2.7.7]$ sudo ntpdate time.windows.com #與當地網絡時間同步
12 May 12:33:09 ntpdate[2571]: adjust time server 13.70.22.122 offset 0.029582 sec
[[email protected] hadoop-2.7.7]$ date #查看是否同步成功
Sun May 12 12:33:16 CST 2019

centos7 + hadoop 2.7.7 完全分布式搭建