大数据Hadoop伪分布式集群搭建

安装hadoop
-------------------
1.安装jdk
a)下载jdk-8u65-linux-x64.tar.gz
b)tar开
$>su centos ; cd ~
$>mkdir downloads
$>cp /mnt/hdfs/downloads/bigdata/jdk-8u65-linux-x64.tar.gz ~/downlooads
$>tar -xzvf jdk-8u65-linux-x64.tar.gz
c)创建/soft文件夹
$>sudo mkdir /soft
$>sudo chown centos:centos /soft
d)移动tar开的文件到/soft下
$>mv ~/downloads/jdk-1.8.0_65 /soft/
e)创建符号连接
$>ln -s /soft/jdk-1.8.0_65 /soft/jdk
f)验证jdk安装是否成功
$>cd /soft/jdk/bin
$>./java -version


centos配置环境变量
------------------------
1.编辑/etc/profile
$>sudo nano /etc/profile
...
export JAVA_HOME=/soft/jdk
exprot PATH=$PATH:$JAVA_HOME/bin
2.使环境变量即刻生效
$>source /etc/profile

3.进入任意目录下,测试是否ok
$>cd ~
$>java -version


安装hadoop
-------------------------
1.安装hadoop
a)下载hadoop-2.7.3.tar.gz
b)tar开
$>su centos ; cd ~
$>cp /mnt/hdfs/downloads/bigdata/hadoop-2.7.3.tar.gz ~/downloads
$>tar -xzvf hadoop-2.7.3.tar.gz
c)无
d)移动tar开的文件到/soft下
$>mv ~/downloads/hadoop-2.7.3 /soft/
e)创建符号连接
$>ln -s /soft/hadoop-2.7.3 /soft/hadoop
f)验证jdk安装是否成功
$>cd /soft/hadoop/bin
$>./hadoop version

2.配置hadoop环境变量
$>sudo nano /etc/profile
...
export JAVA_HOME=/soft/jdk
exprot PATH=$PATH:$JAVA_HOME/bin


export HADOOP_HOME=/soft/hadoop
export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin

3.生效

$>source /etc/profile

        

        配置hadoop
--------------------
1.standalone(local)
nothing !
不需要启用单独的hadoop进程。

2.Pseudodistributed mode
伪分布模式。
a)进入${HADOOP_HOME}/etc/hadoop目录
b)编辑core-site.xml
<?xml version="1.0"?>
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://localhost/</value>
</property>

</configuration>

c)编辑hdfs-site.xml
<?xml version="1.0"?>
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>

</configuration>

d)编辑mapred-site.xml
注意:cp mapred-site.xml.template mapred-site.xml
<?xml version="1.0"?>
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>

</configuration>

e)编辑yarn-site.xml
<?xml version="1.0"?>
<configuration>
<property>
<name>yarn.resourcemanager.hostname</name>
<value>localhost</value>
</property>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>

</configuration>

f)配置SSH
1)检查是否安装了ssh相关软件包(openssh-server + openssh-clients + openssh)
$yum list installed | grep ssh


2)检查是否启动了sshd进程
$>ps -Af | grep sshd

3)在client侧生成公私秘钥对。
$>ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa

4)生成~/.ssh文件夹，里面有id_rsa(私钥) + id_rsa.pub(公钥)


5)追加公钥到~/.ssh/authorized_keys文件中(文件名、位置固定)
$>cd ~/.ssh
$>cat id_rsa.pub >> authorized_keys

6)修改authorized_keys的权限为644.
$>chmod 644 authorized_keys

7)测试
$>ssh localhost