Hadoop使用教程(2):单节点环境搭建实战中级

步骤：
1、创建用户
sudo useradd -m hadoop -s /bin/bash #创建hadoop用户
sudo passwd hadoop #修改密码
sudo adduser hadoop sudo #增加管理员权限

2、注销当前用户并使用hadoop用户登陆

3、更新资源库
sudo apt-get update #更新apt

4、安装vim
sudo apt-get install vim

5、安装ssh
sudo apt-get install openssh-server

cd ~
mkdir .ssh
cd ~/.ssh/
ssh-keygen -t rsa
cat id_rsa.pub>>authorized_keys #加入权限

6、安装Java环境
sudo apt-get install openjdk-8-jre openjdk-8-jdk

vim ~/.bashrc #设置JAVA_HOME

7、在文件第一行添加
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
export HADOOP_OPTS="-Djava.library.path=${HADOOP_HOME}/lib/native"

8、使变量生效
source ~/.bashrc

9、安装hadoop 2
cd /usr/local
sudo wget https://mirrors.cnnic.cn/apache/hadoop/common/hadoop-2.10.1/hadoop-2.10.1.tar.gz

sudo tar -zxvf ./hadoop-2.10.1.tar.gz #解压

sudo mv ./hadoop-2.10.1/ ./hadoop #改名
sudo chown -R hadoop ./hadoop #修改文件权限

10、修改配置文件
vim /usr/local/hadoop/etc/hadoop/core-site.xml
修改部分

<property>
    <name>hadoop.tmp.dir</name>
    <value>file:/usr/local/hadoop/tmp</value>
</property>
<property>
    <name>fs.defaultFS</name>
    <value>hdfs://localhost:9000</value>
</property>

配置
vim /usr/local/hadoop/etc/hadoop/hdfs-site.xml

<configuration>
    <property>
        <name>dfs.replication</name>
        <value>1</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>

启动
cd /usr/local/hadoop #此目录为hadoop的安装目录
bin/hdfs namenode -format # cd bin && ./hdfs namenode -format

sbin/start-dfs.sh #cd sbin && ./start-dfs.sh

jps

WORDCOUNT实例：
bin/hdfs dfs -mkdir -p /user/hadoop
bin/hdfs dfs -mkdir input
bin/hdfs dfs -put etc/hadoop/*.xml input

bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.10.1.jar wordcount input output

bin/hdfs dfs -cat output/*