Hadoop 集群环境搭建续

集群环境规划

centos102	centos103	centos104
NameNode	ResourceManager	SecondaryNameNode
DataNode	DataNode	DataNode
NodeManager	NodeManager	NodeManager

配置免密登录

生成密钥对ssh-keygen -t rsa
一路回车即可

将本机公钥拷贝到目标机器 ssh-copy-id 目标机器hostname
如果本机没有ssh-copy-id命令，需要自己安装。
安装ssh-copy-id（https://blog.csdn.net/u014609263/article/details/89448245）
sudo yum -y install openssh-clients

在三台机器上都执行以下4条指令，配置三台机器间的免密登录

ssh-keygen -t rsa
ssh-copy-id centos102
ssh-copy-id centos103
ssh-copy-id centos104

core-site.xml

<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://centos102:9000</value>
    </property>
    <property>
        <name>hadoop.tmp.dir</name>
        <value>/opt/moudle/hadoop-2.7.3/data</value>
    </property>

</configuration>

hdfs-site.xml

<configuration>
    <!-- 指定HDFS副本数量 -->
    <property>
        <name>dfs.replication</name>
        <value>3</value>
    </property>

    <!-- 指定SecondaryNameNode -->
    <property>
        <name>dfs.namenode.secondary.http-address</name>
        <value>centos104:50090</value>
    </property>
</configuration>

mapred-site.xml

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

yarn-site.xml

<configuration>
    <property>
        <name>yarn.resourcemanager.hostname</name>
        <value>centos103</value>
    </property>
    <property>
        <name>yarn.nodemanager.aux-services</name>
        <value>mapreduce_shuffle</value>
    </property>
</configuration>

etc/hadoop/slaves

centos102
centos103
centos104

同步以上配置到其他机器
xsync /opt/moudle/hadoop-2.7.3/etc/

在NameNode机器centos102 上执行格式化hdfs namenode -format
在centos102上执行start-dfs.sh
在centos103上执行start-yarn.sh

通过jps 命令查看

[hadoop@centos102 ~]$ jps
25552 NodeManager
24389 DataNode
27803 Jps
24190 NameNode

[hadoop@centos103 ~]$ jps
24978 ResourceManager
25130 NodeManager
27996 Jps
23980 DataNode

[hadoop@centos104 ~]$ jps
28049 Jps
23991 DataNode
25081 NodeManager
24233 SecondaryNameNode

访问 HDFS http://192.168.56.102:50070/
访问 YARN http://192.168.56.103:8088/

执行WordCount程序，在NameNode机器centos102上操作。
待统计文件wc.txt 内容如下，一行使用tab隔开

[hadoop@centos102 ~]$ cat wc.txt 
helloworld      test
hadoop
centos
hdfs
yarn
namenode        datanode

创建目录 hdfs dfs -mkdir /wcinput

上传待统计的文件wc.txt
hdfs dfs -put wc.txt /wcinput/

执行MapReduce程序
hadoop jar /opt/moudle/hadoop-2.7.3/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.3.jar wordcount /wcinput/ /wcoutput

查看执行结果
hdfs dfs -cat /wcoutput/*

[hadoop@centos102 ~]$ hdfs dfs -cat /wcoutput/*
centos  1
datanode        1
hadoop  1
hdfs    1
helloworld      1
namenode        1
test    1
yarn    1