Hadoop -分布式环境搭建安装配置
集群环境：
1 NameNode(真实主机):
Linux yan-Server 3.4.36-gentoo #3 SMP Mon Apr 1 14:09:12 CST 2013 x86_64 AMD Athlon(tm) X4 750K Quad Core Processor AuthenticAMD GNU/Linux
2 DataNode1(虚拟机):
Linux node1 3.5.0-23-generic #35~precise1-Ubuntu SMP Fri Jan 25 17:13:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
3 DataNode2(虚拟机):
Linux node2 3.5.0-23-generic #35~precise1-Ubuntu SMP Fri Jan 25 17:13:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
4 DataNode3(虚拟机):
Linux node3 3.5.0-23-generic #35~precise1-Ubuntu SMP Fri Jan 25 17:13:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
原创作品，转载请标明：
http://blog.csdn.net/yming0221/article/details/8989203
1.安装VirtualBox虚拟机
Gentoo下直接命令编译安装，或者官网下载二进制安装包直接安装：
emerge -av virtualbox
2.虚拟机下安装Ubuntu 12.04 LTS
使用Ubuntu镜像安装完成后，然后再克隆另外两台虚拟主机（这里会遇到克隆的主机启动的时候主机名和MAC地址会是一样的，局域网会造成冲突）
主机名修改文件
/etc/hostname
MAC地址修改需要先删除文件
/etc/udev/rules.d/70-persistent-net.rules
然后在启动之前设置VirtualBox虚拟机的MAC地址
启动后会自动生成删除的文件，配置网卡的MAC地址。
为了更方便的在各主机之间共享文件，可以启动主机yan-Server的NFS，将命令加入/etc/rc.local中，让客户端自动挂载NFS目录。
删除各虚拟机的NetworkManager，手动设置静态的IP地址，例如node2主机的/etc/network/interfaces文件配置如下：
auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 192.168.137.202 gateway 192.168.137.1 netmask 255.255.255.0 network 192.168.137.0 broadcast 192.168.137.255
主机的基本环境设置完毕，下面是主机对应的IP地址
| 类型 | 主机名 | IP |
| NameNode | yan-Server | 192.168.137.100 |
| DataNode | node1 | 192.168.137.201 |
| DataNode | node2 | 192.168.137.202 |
| DataNode | node3 | 192.168.137.203 |
设置方式是修改/etc/default/grub文件将下面的一行解除注释
GRUB_TERMINAL=console
然后update-grub即可。
3.Hadoop环境的配置
3.1配置JDK环境（之前就做好了，这里不再赘述）
export JAVA_HOME=/opt/jdk1.7.0_21 export PATH=$JAVA_HOME/bin:$PATH export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
3.2在官网下载Hadoop，然后解压到/opt/目录下面（这里使用的是hadoop-2.0.4-alpha）
然后进入目录/opt/hadoop-2.0.4-alpha/etc/hadoop，配置hadoop文件
修改文件hadoop-env.sh
export HADOOP_FREFIX=/opt/hadoop-2.0.4-alpha
export HADOOP_COMMON_HOME=${HADOOP_FREFIX}
export HADOOP_HDFS_HOME=${HADOOP_FREFIX}
export PATH=$PATH:$HADOOP_FREFIX/bin
export PATH=$PATH:$HADOOP_FREFIX/sbin
export HADOOP_MAPRED_HOME=${HADOOP_FREFIX}
export YARN_HOME=${HADOOP_FREFIX}
export HADOOP_CONF_HOME=${HADOOP_FREFIX}/etc/hadoop
export YARN_CONF_DIR=${HADOOP_FREFIX}/etc/hadoop
export JAVA_HOME=/opt/jdk1.7.0_21修改文件hdfs-site.xml
<configuration> <property> <name>dfs.namenode.name.dir</name> <value>file:/opt/hadoop-2.0.4-alpha/workspace/name</value> <description>Determines where on the local filesystem the DFS name node should store the name table.If this is a comma-delimited list of directories,then name table is replicated in all of the directories,for redundancy.</description> <final>true</final> </property> <property> <name>dfs.datanode.data.dir</name> <value>file:/opt/hadoop-2.0.4-alpha/workspace/data</value> <description>Determines where on the local filesystem an DFS data node should store its blocks.If this is a comma-delimited list of directories,then data will be stored in all named directories,typically on different devices.Directories that do not exist are ignored. </description> <final>true</final> </property> <property> <name>dfs.replication</name> <value>1</value> </property> <property> <name>dfs.permission</name> <value>false</value> </property> </configuration>
修改文件mapred-site.xml
<configuration> <property> <name>mapreduce.framework.name</name> <value>yarn</value> </property> <property> <name>mapreduce.job.tracker</name> <value>hdfs://yan-Server:9001</value> <final>true</final> </property> <property> <name>mapreduce.map.memory.mb</name> <value>1536</value> </property> <property> <name>mapreduce.map.java.opts</name> <value>-Xmx1024M</value> </property> <property> <name>mapreduce.reduce.memory.mb</name> <value>3072</value> </property> <property> <name>mapreduce.reduce.java.opts</name> <value>-Xmx2560M</value> </property> <property> <name>mapreduce.task.io.sort.mb</name> <value>512</value> </property> <property> <name>mapreduce.task.io.sort.factor</name> <value>100</value> </property> <property> <name>mapreduce.reduce.shuffle.parallelcopies</name> <value>50</value> </property> <property> <name>mapred.system.dir</name> <value>file:/opt/hadoop-2.0.4-alpha/workspace/systemdir</value> <final>true</final> </property> <property> <name>mapred.local.dir</name> <value>file:/opt/hadoop-2.0.4-alpha/workspace/localdir</value> <final>true</final> </property> </configuration>
修改文件yarn-env.xml
export HADOOP_FREFIX=/opt/hadoop-2.0.4-alpha
export HADOOP_COMMON_HOME=${HADOOP_FREFIX}
export HADOOP_HDFS_HOME=${HADOOP_FREFIX}
export PATH=$PATH:$HADOOP_FREFIX/bin
export PATH=$PATH:$HADOOP_FREFIX/sbin
export HADOOP_MAPRED_HOME=${HADOOP_FREFIX}
export YARN_HOME=${HADOOP_FREFIX}
export HADOOP_CONF_HOME=${HADOOP_FREFIX}/etc/hadoop
export YARN_CONF_DIR=${HADOOP_FREFIX}/etc/hadoop
export JAVA_HOME=/opt/jdk1.7.0_21修改文件yarn-site.xml
<configuration> <property> <name>yarn.resourcemanager.address</name> <value>yan-Server:8080</value> </property> <property> <name>yarn.resourcemanager.scheduler.address</name> <value>yan-Server:8081</value> </property> <property> <name>yarn.resourcemanager.resource-tracker.address</name> <value>yan-Server:8082</value> </property> <property> <name>yarn.nodemanager.aux-services</name> <value>mapreduce.shuffle</value> </property> <property> <name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name> <value>org.apache.hadoop.mapred.ShuffleHandler</value> </property> </configuration>
将配置好的Hadoop复制到各DataNode（这里DataNode的JDK配置和主机的配置是一致的，不需要再修改JDK的配置）
3.3 修改主机的/etc/hosts，将NameNode加入该文件
192.168.137.100 yan-Server 192.168.137.201 node1 192.168.137.202 node2 192.168.137.203 node3
3.4 修改各DataNode的/etc/hosts文件，也添加上述的内容
192.168.137.100 yan-Server 192.168.137.201 node1 192.168.137.202 node2 192.168.137.203 node3
3.5 配置SSH免密码登录（所有的主机都使用root用户登录）
主机上运行命令
ssh-kengen -t rsa一路回车，然后复制.ssh/id_rsa.pub为各DataNode的root用户目录.ssh/authorized_keys文件
然后在主机上远程登录一次
ssh root@node1首次登录可能会需要输入密码，之后就不再需要。（其他的DataNode也都远程登录一次确保可以免输入密码登录）
4.启动Hadoop
为了方便，在主机的/etc/profile配置hadoop的环境变量，如下：
export HADOOP_PREFIX="/opt/hadoop-2.0.4-alpha"
export PATH=$PATH:$HADOOP_PREFIX/bin
export PATH=$PATH:$HADOOP_PREFIX/sbin
export HADOOP_MAPRED_HOME=${HADOOP_PREFIX}
export HADOOP_COMMON_HOME=${HADOOP_PREFIX}
export HADOOP_HDFS_HOME=${HADOOP_PREFIX}
export YARN_HOME=${HADOOP_PREFIX}
4.1 格式化NameNode
hdfs namenode -format
4.2 启动全部进程
start-all.sh
在浏览器查看，地址：
所有数据节点DataNode正常启动。
4.3 关闭所有进程
stop-all.sh
至此，Hadoop环境搭建基本结束。
上面使用的是alpha版本，不是稳定版，稳定版的配置文件会有所不同，如果照搬会可能导致jobtracker或tasktracker无法启动的问题。遇到问题查看日志文件。
下面是我配置的1.1.2稳定版本的配置文件：
conf/core-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://yan-Server:49000</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/tmp</value>
</property>
</configuration>conf/hadoop-env.sh
export HADOOP_FREFIX=/opt/hadoop-1.1.2
export HADOOP_COMMON_HOME=${HADOOP_FREFIX}
export HADOOP_HDFS_HOME=${HADOOP_FREFIX}
export PATH=$PATH:$HADOOP_FREFIX/bin
export PATH=$PATH:$HADOOP_FREFIX/sbin
export HADOOP_MAPRED_HOME=${HADOOP_FREFIX}
export YARN_HOME=${HADOOP_FREFIX}
export HADOOP_CONF_HOME=${HADOOP_FREFIX}/conf
export YARN_CONF_DIR=${HADOOP_FREFIX}/conf
export JAVA_HOME=/opt/jdk1.7.0_21conf/hdfs-site.xml
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <!-- Put site-specific property overrides in this file. --> <configuration> <property> <name>dfs.name.dir</name> <value>/opt/hadoop-1.1.2/workspace/name</value> <description>Determines where on the local filesystem the DFS name node should store the name table.If this is a comma-delimited list of directories,then name table is replicated in all of the directories,for redundancy.</description> <final>true</final> </property> <property> <name>dfs.data.dir</name> <value>/opt/hadoop-1.1.2/workspace/data</value> <description>Determines where on the local filesystem an DFS data node should store its blocks.If this is a comma-delimited list of directories,then data will be stored in all named directories,typically on different devices.Directories that do not exist are ignored. </description> <final>true</final> </property> <property> <name>dfs.replication</name> <value>1</value> </property> <property> <name>dfs.permission</name> <value>false</value> </property> </configuration>
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <!-- Put site-specific property overrides in this file. --> <configuration> <property> <name>mapred.job.tracker</name> <value>hdfs://yan-Server:9001</value> <final>true</final> </property> </configuration>
conf/masters中填写NameNode主机名
conf/slaves中填写DataNode主机名
参考：
1.实战Hadoop--开启通向云计算的捷径（刘鹏）
2.http://www.cnblogs.com/aniuer/archive/2012/07/16/2594448.html
