一、前期准备:
下载hadoop:
二、硬件环境
共有3台机器，均使用的CentOS，Java使用的是jdk1.6.0。
三、安装JAVA6
sudo apt-get install sun-java6-jdk
/etc/environment
打开之后加入：#中间是以英文的冒号隔开，记得windows中是以英文的分号做为分隔的
CLASSPATH=.:/usr/local/java/lib
JAVA_HOME=/usr/local/java
三、配置host表
[root@hadoop ~]# vi /etc/hosts
127.0.0.1 localhost
192.168.13.100 namenode
192.168.13.108 datanode1
192.168.13.110 datanode2
[root@test ~]# vi /etc/hosts
127.0.0.1 localhost
192.168.13.100 namenode
192.168.13.108 datanode1
[root@test2 ~]# vi /etc/host
127.0.0.1 localhost
192.168.13.100 namenode
192.168.13.110 datanode2
添加用户和用户组
addgroup hadoop
adduser hadoop
usermod -a -G hadoop hadoop
passwd hadoop
配置ssh:
服务端:
su hadoop
ssh-keygen -t rsa
cp id_rsa.pub authorized_keys
客户端
chmod 700 /home/hadoop
chmod 755 /home/hadoop/.ssh
su hadoop
cd /home
mkdir .ssh
服务端:
chmod 644 /home/hadoop/.ssh/authorized_keys
scp authorized_keys datanode1:/home/hadoop/.ssh/
scp authorized_keys datanode2:/home/hadoop/.ssh/
ssh datanode1
ssh datanode2
如果ssh配置好了就会出现以下提示信息
The authenticity of host [dbrg-2] can't be established.
Key fingerpr is 1024 5f:a0:0b:65:d3:82:df:ab:44:62:6d:98:9c:fe:e9:52.
Are you sure you want to continue connecting (yes/no)?
OpenSSH告诉你它不知道这台主机但是你不用担心这个问题你是第次登录这台主机键入“yes”这将把
这台主机“识别标记”加到“~/.ssh/know_hosts”文件中第 2次访问这台主机时候就不会再显示这条提示信
不过别忘了测试本机ssh dbrg-1
mkdir /home/hadoop/HadoopInstall
tar -zxvf hadoop-0.20.1.tar.gz -C /home/hadoop/HadoopInstall/
cd /home/hadoop/HadoopInstall/
ln -s hadoop-0.20.1 hadoop
export JAVA_HOME=/usr/local/java
export CLASSPATH=.:/usr/local/java/lib
export HADOOP_HOME=/home/hadoop/HadoopInstall/hadoop
export HADOOP_CONF_DIR=/home/hadoop/hadoop-conf
export PATH=$HADOOP_HOME/bin:$PATH
cd $HADOOP_HOME/conf/
mkdir /home/hadoop/hadoop-conf
cp hadoop-env.sh core-site.xml hdfs-site.xml mapred-site.xml masters slaves /home/hadoop/hadoop-conf
vi $HADOOP_HOME/hadoop-conf/hadoop-env.sh
# The java implementation to use. Required. --修改成你自己jdk安装的目录
export JAVA_HOME=/usr/local/java
export HADOOP_CLASSPATH=.:/usr/local/java/lib
# The maximum amount of heap to use, in MB. Default is 1000.--根据你的内存大小调整
export HADOOP_HEAPSIZE=200
vi /home/hadoop/.bashrc
export JAVA_HOME=/usr/local/java
export CLASSPATH=.:/usr/local/java/lib
export HADOOP_HOME=/home/hadoop/HadoopInstall/hadoop
export HADOOP_CONF_DIR=/home/hadoop/hadoop-conf
export PATH=$HADOOP_HOME/bin:$PATH
配置
namenode
#vi $HADOOP_CONF_DIR/slaves
192.168.13.108
192.168.13.110
#vi $HADOOP_CONF_DIR/core-site.xml
fs.default.name
hdfs://192.168.13.100:9000
#vi $HADOOP_CONF_DIR/hdfs-site.xml
dfs.replication
3
Default block replication.
The actual number of replications can be specified when the file is created.
The default is used if replication is not specified in create time.
#vi $HADOOP_CONF_DIR/mapred-site.xml
mapred.job.tracker
192.168.13.100:11000
~
在slave上的配置文件如下(hdfs-site.xml不需要配置)：
[root@test12 conf]# cat core-site.xml
fs.default.name
hdfs://namenode:9000
[root@test12 conf]# cat mapred-site.xml
mapred.job.tracker
namenode:11000
启动
export PATH=$HADOOP_HOME/bin:$PATH
hadoop namenode -format
start-all.sh
停止stop-all.sh
在hdfs上创建danchentest文件夹，上传文件到此目录下
$HADOOP_HOME/bin/hadoop fs -mkdir danchentest
$HADOOP_HOME/bin/hadoop fs -put $HADOOP_HOME/README.txt danchentest
cd $HADOOP_HOME
hadoop jar hadoop-0.20.1-examples.jar wordcount /user/hadoop/danchentest/README.txt output1
09/12/21 18:31:44 INFO input.FileInputFormat: Total input paths to process : 1
09/12/21 18:31:45 INFO mapred.JobClient: Running job: job_200912211824_0002
09/12/21 18:31:46 INFO mapred.JobClient: map 0% reduce 0%
09/12/21 18:31:53 INFO mapred.JobClient: map 100% reduce 0%
09/12/21 18:32:05 INFO mapred.JobClient: map 100% reduce 100%
09/12/21 18:32:07 INFO mapred.JobClient: Job complete: job_200912211824_0002
09/12/21 18:32:07 INFO mapred.JobClient: Counters: 17
09/12/21 18:32:07 INFO mapred.JobClient: Job Counters
09/12/21 18:32:07 INFO mapred.JobClient: Launched reduce tasks=1
查看输出结果文件，这个文件在hdfs上
[root@test11 hadoop]# hadoop fs -ls output1
Found 2 items
drwxr-xr-x - root supergroup 0 2009-09-30 16:01 /user/root/output1/_logs
-rw-r--r-- 3 root supergroup 1306 2009-09-30 16:01 /user/root/output1/part-r-00000
[root@test11 hadoop]# hadoop fs -cat output1/part-r-00000
(BIS), 1
(ECCN) 1
查看hdfs运行状态,可以通过web界面来访问查看map-reduce信息，
可以通过web界面来访问下面是直接命令行看到的结果。
出现08/01/25 16:31:40 INFO ipc.Client: Retrying connect to server: foo.bar.com/1.1.1.1:53567. Already tried 1 time(s).
的原因是没有格式化:hadoop namenode -format
