在配置集群/分布式模式时,需要修改/usr/local/hadoop/etc/hadoop目录下的配置文件,这里仅设置正常启动所需的设置项,包括slaves,core-site.xml,hdfs-site.xml、yarn-site.xml、mapred-site.xml 共5个文件。
我的环境：
Ubuntu 16.04 TLS
Hadoop 2.6.0

192.168.56.102 Master
192.168.56.105 data1
192.168.56.104 data2
192.168.56.103 data3

(1)修改文件slaves:
sudo gedit /usr/local/hadoop/etc/hadoop/slaves
需要把所有的数据节点的主机名写入该文件，每行一个。

图片.png

（2）修改core-site.xml:
sudo gedit /usr/local/hadoop/etc/hadoop/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/hadoop/tmp</value>
                <description>Abase for other temporary directories.</description>
        </property></configuration>

(3)修改文件hdfs-site.xml
sudo gedit /usr/local/hadoop/etc/hadoop/hdfs-site.xml

<configuration>
        <property>
                <name>dfs.namenode.secondary.http-address</name>
                <value>Master:50090</value>
        </property>
        <property>
                <name>dfs.replication</name>
                <value>3</value>
        </property>
        <property>
                <name>dfs.namenode.name.dir</name>
                <value>file:/usr/local/hadoop/tmp/dfs/name</value>
        </property>
        <property>
                <name>dfs.datanode.data.dir</name>
                <value>file:/usr/local/hadoop/tmp/dfs/data</value>
        </property></configuration>

(4)修改文件mapred-site.xml
sudo gedit /usr/local/hadoop/etc/hadoop/mapred-site.xml

<configuration>
        <property>
                <name>mapreduce.framework.name</name>
                <value>yarn</value>
        </property>
        <property>
                <name>mapreduce.jobhistory.address</name>
                <value>Master:10020</value>
        </property>
        <property>
                <name>mapreduce.jobhistory.webapp.address</name>
                <value>Master:19888</value>
        </property></configuration>

(5)修改文件yarn-site.xml
sudo gedit /usr/local/hadoop/etc/hadoop/yarn-site.xml

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

作者：枫雪浅语
链接：https://www.jianshu.com/p/0fbe3738a64a