本文旨在使用一个全新安装好的Linux系统从0开始进行Hadoop伪分布式环境的搭建,以达到快速搭建的目的,从而体验Hadoop的魅力所在,为后面的继续学习提供基础环境。
对使用的系统环境作如下说明:
-
操作系统:CentOS 6.5 64位
-
主机IP地址:10.0.0.131/24
-
主机名:leaf
-
用户名:root
-
hadoop版本:2.6.5
-
jdk版本:1.7
可以看到,这里直接使用root用户,而不是按照大多数的教程创建一个hadoop用户来进行操作,就是为了达到快速搭建Hadoop环境以进行体验的目的。
为了保证后面的操作能够正常完成,请先确认本机是否可以解析到主机名leaf,如果不能,请手动添加解析到/etc/hosts目录中:
1
2
3
4
5
6
|
[root@leaf ~]
# echo "127.0.0.1 leaf" >> /etc/hosts
[root@leaf ~]
# ping leaf
PING leaf (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64
time
=0.043 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64
time
=0.048 ms
64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64
time
=0.046 ms
|
1.rsync软件安装
使用下面命令安装:
1
|
[root@leaf ~]
# yum install -y rsync
|
2.ssh安装与免密码登陆配置
(1)ssh安装
使用下面命令安装
1
|
[root@leaf ~]
# yum install -y openssh-server openssh-clients
|
(2)ssh免密码登陆配置
因为Hadoop使用ssh协议来管理远程守护进程,所以需要配置免密码登陆。
-
关闭防火墙和selinux
为了确保能够成功配置,在配置前,先把防火墙和selinux关闭:
1
2
3
4
5
6
7
8
9
10
|
# 关闭防火墙
[root@leaf ~]
# /etc/init.d/iptables stop
[root@leaf ~]
# chkconfig --level 3 iptables off
# 关闭selinux
[root@leaf ~]
# setenforce 0
[root@leaf ~]
# sed -i s/SELINUX=enforcing/SELINUX=disabled/g /etc/selinux/config
[root@leaf ~]
# cat /etc/selinux/config | grep disabled
# disabled - No SELinux policy is loaded.
SELINUX=disabled
|
-
生成密钥对
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
[root@leaf ~]
# mkdir .ssh
[root@leaf ~]
# ssh-keygen -t dsa -P '' -f .ssh/id_dsa
Generating public
/private
dsa key pair.
Your identification has been saved
in
.
ssh
/id_dsa
.
Your public key has been saved
in
.
ssh
/id_dsa
.pub.
The key fingerprint is:
5b:af:7c:45:f3:ff:
dc
:50:f5:81:4b:1e:5c:c1:86:90 root@leaf
The key's randomart image is:
+--[ DSA 1024]----+
| .o oo.|
| E..oo |
| =...|
| o = +|
| S . + oo|
| o . ...|
| . ... .|
| . .. oo|
| o. =|
+-----------------+
|
-
将公钥添加到本地信任列表
1
|
[root@leaf ~]
# cat .ssh/id_dsa.pub >> .ssh/authorized_keys
|
-
验证
上面三步完成后就完成了免密码登陆的配置,可以使用下面的命令进行验证:
1
2
3
4
5
6
7
|
[root@leaf ~]
# ssh localhost
The authenticity of host
'localhost (::1)'
can't be established.
RSA key fingerprint is d1:0d:ed:eb:e7:d1:2f:02:23:70:ef:11:14:4e:fa:42.
Are you sure you want to
continue
connecting (
yes
/no
)?
yes
Warning: Permanently added
'localhost'
(RSA) to the list of known hosts.
Last login: Wed Aug 30 04:28:01 2017 from 10.0.0.1
[root@leaf ~]
#
|
在第一次登陆的时候需要输入yes,之后再登陆时就可以直接登陆了:
1
2
3
|
[root@leaf ~]
# ssh localhost
Last login: Wed Aug 30 04:44:02 2017 from localhost
[root@leaf ~]
#
|
3.jdk安装与配置
(1)jdk下载
这里使用的是jdk1.7版本,可以到下面的网站进行下载:
http://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html
下载完成后,可以使用winscp上传到/root目录下,如下:
1
2
|
[root@leaf ~]
# ls -lh jdk-7u80-linux-x64.tar.gz
-rw-r--r--. 1 root root 147M Aug 29 12:05 jdk-7u80-linux-x64.
tar
.gz
|
(2)jdk安装
将jdk解压到/usr/local目录下,并创建软链接:
1
2
3
4
5
6
7
8
|
[root@leaf ~]
# cp jdk-7u80-linux-x64.tar.gz /usr/local/
[root@leaf ~]
# cd /usr/local/
[root@leaf
local
]
# tar -zxf jdk-7u80-linux-x64.tar.gz
[root@leaf
local
]
# ls -ld jdk1.7.0_80/
drwxr-xr-x. 8 uucp 143 4096 Apr 11 2015 jdk1.7.0_80/
[root@leaf
local
]
# ln -s jdk1.7.0_80/ jdk
[root@leaf
local
]
# ls -ld jdk
lrwxrwxrwx. 1 root root 12 Aug 30 04:56 jdk -> jdk1.7.0_80/
|
(3)JAVA_HOME环境变量配置
java命令在/usr/local/jdk/bin目录下:
1
2
3
|
[root@leaf
local
]
# cd jdk/bin/
[root@leaf bin]
# ls -lh java
-rwxr-xr-x. 1 uucp 143 7.6K Apr 11 2015 java
|
配置java环境变量:
1
2
3
|
[root@leaf bin]
# echo 'export JAVA_HOME=/usr/local/jdk/bin' >> /etc/profile
[root@leaf bin]
# echo 'export PATH=$PATH:$JAVA_HOME' >> /etc/profile
[root@leaf bin]
# source /etc/profile
|
这样我们就可以在任何一个目录下使用java相关的命令:
1
2
3
4
5
6
|
[root@leaf ~]
# java -version
java version
"1.7.0_80"
Java(TM) SE Runtime Environment (build 1.7.0_80-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)
[root@leaf ~]
# javac -version
javac 1.7.0_80
|
4.hadoop安装与配置
(1)hadoop下载
这里使用hadoop 2.6.5版本,可以到下面的网站进行下载:
http://hadoop.apache.org/releases.html
选择2.6.5的binary进入相应的页面便可以下载,然后使用winscp上传到/root目录下,如下:
1
2
|
[root@leaf ~]
# ls -lh hadoop-2.6.5.tar.gz
-rw-r--r--. 1 root root 191M Aug 29 19:09 hadoop-2.6.5.
tar
.gz
|
(2)hadoop安装
将hadoop解压到/usr/local目录下,并创建软链接:
1
2
3
4
5
6
7
8
|
[root@leaf ~]
# cp hadoop-2.6.5.tar.gz /usr/local
[root@leaf ~]
# cd /usr/local
[root@leaf
local
]
# tar -zxf hadoop-2.6.5.tar.gz
[root@leaf
local
]
# ls -ld hadoop-2.6.5
drwxrwxr-x. 9 1000 1000 4096 Oct 3 2016 hadoop-2.6.5
[root@leaf
local
]
# ln -s hadoop-2.6.5 hadoop
[root@leaf
local
]
# ls -ld hadoop
lrwxrwxrwx. 1 root root 12 Aug 30 05:05 hadoop -> hadoop-2.6.5
|
(3)hadoop环境变量配置
hadoop相关命令在/usr/local/hadoop/bin和/usr/local/hadoop/sbin目录下,如下所示:
1
2
3
|
[root@leaf
local
]
# cd hadoop/bin/
[root@leaf bin]
# ls -lh hadoop
-rwxr-xr-x. 1 1000 1000 5.4K Oct 3 2016 hadoop
|
配置hadoop环境变量:
1
2
|
[root@leaf bin]
# echo 'export HADOOP_HOME=/usr/local/hadoop/bin:/usr/local/hadoop/sbin' >> /etc/profile
[root@leaf bin]
# echo 'export PATH=$PATH:$HADOOP_HOME' >> /etc/profile
|
这样我们就可以在任何一个目录下使用hadoop相关的命令:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
[root@leaf ~]
# hadoop
Usage: hadoop [--config confdir] COMMAND
where COMMAND is one of:
fs run a generic filesystem user client
version print the version
jar <jar> run a jar
file
checknative [-a|-h] check native hadoop and compression libraries availability
distcp <srcurl> <desturl> copy
file
or directories recursively
archive -archiveName NAME -p <parent path> <src>* <dest> create a hadoop archive
classpath prints the class path needed to get the
credential interact with credential providers
Hadoop jar and the required libraries
daemonlog get
/set
the log level
for
each daemon
trace view and modify Hadoop tracing settings
or
CLASSNAME run the class named CLASSNAME
Most commands print help when invoked w
/o
parameters.
|
(4)hadoop配置
hadoop的配置文件在/usr/local/hadoop/etc/hadoop目录下:
1
2
3
4
5
6
7
8
9
10
|
[root@leaf ~]
# cd /usr/local/hadoop/etc/hadoop/
[root@leaf hadoop]
# ls
capacity-scheduler.xml hadoop-policy.xml kms-log4j.properties ssl-client.xml.example
configuration.xsl hdfs-site.xml kms-site.xml ssl-server.xml.example
container-executor.cfg httpfs-
env
.sh log4j.properties yarn-
env
.cmd
core-site.xml httpfs-log4j.properties mapred-
env
.cmd yarn-
env
.sh
hadoop-
env
.cmd httpfs-signature.secret mapred-
env
.sh yarn-site.xml
hadoop-
env
.sh httpfs-site.xml mapred-queues.xml.template
hadoop-metrics2.properties kms-acls.xml mapred-site.xml.template
hadoop-metrics.properties kms-
env
.sh slaves
|
-
配置core-site.xml
1
2
3
4
5
6
|
<configuration>
<property>
<name>fs.default.name<
/name
>
<value>hdfs:
//localhost
:9000<
/value
>
<
/property
>
<
/configuration
>
|
fs.default.name这个字段下的值用于指定NameNode(HDFS的Master)的IP地址和端口号,如下面的value值hdfs://localhost:9000,就表示HDFS NameNode的IP地址或主机为localhost,端口号为9000.
-
配置hdfs-site.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
|
<configuration>
<property>
<name>dfs.replication<
/name
>
<value>1<
/value
>
<
/property
>
<property>
<name>dfs.name.
dir
<
/name
>
<value>
/root/hdfs-filesystem/name
<
/value
>
<
/property
>
<property>
<name>dfs.data.
dir
<
/name
>
<value>
/root/hdfs-filesystem/data
<
/value
>
<
/property
>
<
/configuration
>
|
dfs.replication用于指定HDFS中每个Block块被复制的次数,起到数据冗余备份的作用;dfs.name.dir用于配置HDFS的NameNode的元数据,以逗号隔开,HDFS会把元数据冗余复制到这些目录下;dfs.data.dir用于配置HDFS的DataNode的数据目录,以逗号隔开,HDFS会把数据存在这些目录下。
-
配置mapred-site.xml
1
2
3
4
5
6
|
<configuration>
<property>
<name>mapred.job.tracker<
/name
>
<value>localhost:9001<
/value
>
<
/property
>
<
/configuration
>
|
mapred.job.tracker字段用于指定MapReduce Jobtracker的IP地址及端口号,如这里IP地址或主机为localhost,9001是MapReduce Jobtracker RPC的交互端口。
-
配置hadoop-env.sh
1
|
export
JAVA_HOME=
/usr/local/jdk
|
5.hadoop启动与测试
(1)格式化HDFS分布式文件系统
执行如下命令:
1
2
3
4
5
6
7
8
|
[root@leaf ~]
# hadoop namenode -format
...
17
/08/30
08:41:29 INFO namenode.NNStorageRetentionManager: Going to retain 1 images with txid >= 0
17
/08/30
08:41:29 INFO util.ExitUtil: Exiting with status 0
17
/08/30
08:41:29 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at leaf
/127
.0.0.1
************************************************************/
|
注意看输出显示是不是跟上面的类似,如果是,则说明操作成功。
(2)启动hadoop服务
执行如下命令:
1
2
3
4
5
6
7
8
9
10
11
12
|
[root@leaf ~]
# start-all.sh
This script is Deprecated. Instead use start-dfs.sh and start-yarn.sh
17
/08/30
08:53:22 WARN util.NativeCodeLoader: Unable to load native-hadoop library
for
your platform... using
builtin
-java classes where applicable
Starting namenodes on [localhost]
localhost: starting namenode, logging to
/usr/local/hadoop-2
.6.5
/logs/hadoop-root-namenode-leaf
.out
localhost: starting datanode, logging to
/usr/local/hadoop-2
.6.5
/logs/hadoop-root-datanode-leaf
.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: starting secondarynamenode, logging to
/usr/local/hadoop-2
.6.5
/logs/hadoop-root-secondarynamenode-leaf
.out
17
/08/30
08:53:48 WARN util.NativeCodeLoader: Unable to load native-hadoop library
for
your platform... using
builtin
-java classes where applicable
starting yarn daemons
starting resourcemanager, logging to
/usr/local/hadoop-2
.6.5
/logs/yarn-root-resourcemanager-leaf
.out
localhost: starting nodemanager, logging to
/usr/local/hadoop-2
.6.5
/logs/yarn-root-nodemanager-leaf
.out
|
(3)hadoop服务测试
启动完成后,执行jps命令,可以看到hadoop运行的守护进程,如下:
1
2
3
4
5
6
7
|
[root@leaf ~]
# jps
4167 SecondaryNameNode
4708 Jps
3907 NameNode
4394 NodeManager
4306 ResourceManager
3993 DataNode
|
也可以通过在浏览器中输入地址来访问相关页面,这里访问NameNode的页面,地址为http://10.0.0.131:50070,如下:
访问DataNode的页面,地址为http://10.0.0.131:50075,如下
本文转自 xpleaf 51CTO博客,原文链接:http://blog.51cto.com/xpleaf/1960982,如需转载请自行联系原作者