检测当前系统下的jdk安装情况：
[root@Centos 桌面]# rpm -qa | grep java
tzdata-java-2012j-1.el6.noarch
java-1.7.0-openjdk-1.7.0.9-2.3.4.1.el6_3.x86_64
java-1.6.0-openjdk-1.6.0.0-1.50.1.11.5.el6_3.x86_64
卸载当前所有的jdk：
[root@Centos 桌面]# rpm -e --nodeps tzdata-java-2012j-1.el6.noarch
[root@Centos 桌面]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.9-2.3.4.1.el6_3.x86_64
[root@Centos 桌面]# rpm -e --nodeps java-1.6.0-openjdk-1.6.0.0-1.50.1.11.5.el6_3.x86_64
复查是否卸载完全：无输出则卸载干净：
[root@Centos 桌面]# rpm -qa | grep java
[root@Centos 桌面]#
安装自己下载的jdk并配置环境变量，详尽参考“linux学习/NO.7”
······················································· JDK安装完成······························································
······················································· hadoop的安装开始··················································
1.在hadoop的conf目录下配置 hadoop-env.sh core-site.xml hdfs-site.xml mapred-site.xml ，
首先解压hadoop.
1.1 在hadoop-env.sh里的配置hadoop的JDK环境
---------------------------------------------
[root@Centos ~]# cd hadoop-1.2.1/
[root@Centos hadoop-1.2.1]# cd conf
[root@Centos conf]# vi hadoop-env.sh
---------------------------------------------
配置信息如下：
export JAVA_HOME=/root/jdk1.8.0_65
1.2 在core-site.xml里的配置hadoop的HDFS地址及端口号
------------------------------------------------
[root@Centos conf]# vi core-site.xml
------------------------------------------------
配置信息如下：
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>
1.3 在hdfs-site.xml里的配置hadoop的HDFS的配置
-------------------------------------------------
[root@Centos conf]# vi hdfs-site.xml
-------------------------------------------------
配置信息如下：
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
1.4 在mapred-site.xml里的配置hadoop的HDFS的配置
-------------------------------------------------
[root@Centos conf]# vi mapred-site.xml
--------------------------------------------
配置信息如下：
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>localhost:9001</value>
</property>
</configuration>
2.ssh免密码登录
--------------------------------------------------------------------
[root@Centos conf]# cd /root
[root@Centos ~]# ssh-keygen -t rsa
输出：
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
ed:48:64:29:62:37:c1:e9:3d:84:bf:ad:4e:50:5e:66 root@Centos
The key's randomart image is:
+--[ RSA 2048]----+
| ..o |
| +... |
| o.++= E |
| . o.B+= |
| . S+. |
| o.o. |
| o.. |
| .. |
| .. |
+-----------------+
c[root@Centos ~]# cd .ssh
[root@Centos .ssh]# ls
id_rsa id_rsa.pub
[root@Centos .ssh]# cp id_rsa.pub authorized_keys
[root@Centos .ssh]# ls
authorized_keys id_rsa id_rsa.pub
[root@Centos .ssh]# ssh localhost
The authenticity of host 'localhost (::1)' can't be established.
RSA key fingerprint is 3f:84:db:2f:53:a9:09:a6:61:a2:3a:82:80:6c:af:1a.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'localhost' (RSA) to the list of known hosts.
-------------------------------------------------------------------------------
验证免密码登录
-------------------------------------------------------------------------------
[root@Centos ~]# ssh localhost
Last login: Sun Apr 3 23:19:51 2016 from localhost
[root@Centos ~]# ssh localhost
Last login: Sun Apr 3 23:20:12 2016 from localhost
Connection to localhost closed.
[root@Centos ~]#
----------------------------SSH免密码登录设置成功----------------------------
格式化HDFS：
[root@Centos ~]# cd /root/hadoop-1.2.1/
[root@Centos hadoop-1.2.1]# bin/hadoop namenode -format
输出：
16/04/03 23:24:12 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = java.net.UnknownHostException: Centos: Centos: unknown error
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 1.2.1
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2 -r 1503152; compiled by 'mattf' on Mon Jul 22 15:23:09 PDT 2013
STARTUP_MSG: java = 1.8.0_65
************************************************************/
16/04/03 23:24:13 INFO util.GSet: Computing capacity for map BlocksMap
16/04/03 23:24:13 INFO util.GSet: VM type = 64-bit
16/04/03 23:24:13 INFO util.GSet: 2.0% max memory = 1013645312
16/04/03 23:24:13 INFO util.GSet: capacity = 2^21 = 2097152 entries
16/04/03 23:24:13 INFO util.GSet: recommended=2097152, actual=2097152
16/04/03 23:24:15 INFO namenode.FSNamesystem: fsOwner=root
16/04/03 23:24:15 INFO namenode.FSNamesystem: supergroup=supergroup
16/04/03 23:24:15 INFO namenode.FSNamesystem: isPermissionEnabled=true
16/04/03 23:24:15 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
16/04/03 23:24:15 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
16/04/03 23:24:15 INFO namenode.FSEditLog: dfs.namenode.edits.toleration.length = 0
16/04/03 23:24:15 INFO namenode.NameNode: Caching file names occuring more than 10 times
16/04/03 23:24:17 INFO common.Storage: Image file /tmp/hadoop-root/dfs/name/current/fsimage of size 110 bytes saved in 0 seconds.
16/04/03 23:24:18 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/tmp/hadoop-root/dfs/name/current/edits
16/04/03 23:24:18 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/tmp/hadoop-root/dfs/name/current/edits
16/04/03 23:24:18 INFO common.Storage: Storage directory /tmp/hadoop-root/dfs/name has been successfully formatted.
16/04/03 23:24:18 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at java.net.UnknownHostException: Centos: Centos: unknown error
************************************************************/
-----------------------------------------------------------------------------
此时格式化节点报错：Centos: unknown error--------紧接着下一步配置
--------------------------------------------------------------------------
[root@Centos hadoop-1.2.1]# vi /etc/hosts
配置信息如下：
127.0.0.1 localhost Centos
-------------------------------------------------------------------------
再一次进行格式化
--------------------------------------------------------------------------
[root@Centos hadoop-1.2.1]# vi /etc/hosts
[root@Centos hadoop-1.2.1]# bin/hadoop namenode -format
具体情况如下图：
---------------------------namenode格式化成功------------------------------
启动hadoop ：
关闭防火墙命令行 # service iptables stop
启动hadoop集群命令行 # start-all.sh
关闭hadoop集群命令行 # stop-all.sh
关闭防火墙：# service iptables stop
启动hadoop集群 ：
[root@Centos hadoop-1.2.1]# bin/start-all.sh
输出：
starting namenode, logging to /root/hadoop-1.2.1/libexec/../logs/hadoop-root-namenode-Centos.out
localhost: starting datanode, logging to /root/hadoop-1.2.1/libexec/../logs/hadoop-root-datanode-Centos.out
localhost: starting secondarynamenode, logging to /root/hadoop-1.2.1/libexec/../logs/hadoop-root-secondarynamenode-Centos.out
starting jobtracker, logging to /root/hadoop-1.2.1/libexec/../logs/hadoop-root-jobtracker-Centos.out
localhost: starting tasktracker, logging to /root/hadoop-1.2.1/libexec/../logs/hadoop-root-tasktracker-Centos.out
验证集群是否正常启动----5个节点在列表中则启动成功
再次验证启动项目
[root@Centos hadoop-1.2.1]# cd /root/mahout-distribution-0.6/
[root@Centos mahout-distribution-0.6]# jps
30692 SecondaryNameNode
30437 NameNode
31382 Jps
30903 TaskTracker
30775 JobTracker
30553 DataNode
[root@Centos mahout-distribution-0.6]# jps
30692 SecondaryNameNode
31477 Jps
30437 NameNode
30903 TaskTracker
30775 JobTracker
30553 DataNode
[root@Centos mahout-distribution-0.6]# cd /home/hadoop-1.2.1
关闭hadoop集群
[root@Centos hadoop-1.2.1]# bin/stop-all.sh
stopping jobtracker
localhost: stopping tasktracker
stopping namenode
localhost: stopping datanode
localhost: stopping secondarynamenode
[root@Centos hadoop-1.2.1]#
------------------------hadoop伪分布式安装成功------------------------
mahout的安装
1.解压安装mahout ：解压到hadoop目录中
[root@Centos hadoop-1.2.1]# tar zxvf mahout-distribution-0.6.tar.gz
2.配置环境变量
export HADOOP_HOME=/root/hadoop-1.2.1
export HADOOP_CONF_DIR=/root/hadoop-1.2.1/conf
export MAHOUT_HOME=/root/hadoop-1.2.1/mahoutdistribution-0.6
export MAHOUT_CONF_DIR=/root/hadoop-1.2.1/mahoutdistribution-0.6/conf
export PATH=$PATH:$MAHOUT_HOME/conf:$MAHOUT_HOME/bin
3.测试mahout的启动
配置环境变量过程如下图：
--------------------------------------mahout安装成------------------------------------