HDFS:
NameNode :管理节点
DataNode :数据节点
SecondaryNamenode : 数据源信息备份整理节点
MapReduce
JobTracker :任务管理节点
Tasktracker :任务运行节点
准备4台服务器,操作系统为 Centos 6.4 最小化安装
NameNode 192.168.2.10 hostname namenode
DataNode 192.168.2.11 hostname:datanode1
DataNode 192.168.2.12 hostname:datanode2
JobTracker 192.168.2.10 (也可单独配置一台,也可以与NameNode公用,这里只用到了HDFS,这台可有可无,准备上面4台即可)
TaskTracker (与DataNode共用)
设置网络使其可以互访,然后关闭防火墙与selinux
# yum update -y
# lokkit --disabled --selinux=disabled
Hadoop 重要的端口
1.Job Tracker 管理界面: 50030
2.HDFS 管理界面 : 50070
3.HDFS通信端口: 9000
4.MapReduce通信端口: 9001
过程 141.3. Hadoop - 准备工作
-
为所有服务器安装Java运行环境
以 CentOS 6.4 为例
# yum install java-1.7.0-openjdk
-
在所有服务器上安装 Hadoop
安装方案有下面两种 RPM与YUM,选择其中一种
# rpm -ivh http://ftp.cuhk.edu.hk/pub/packages/apache.org/hadoop/common/hadoop-1.1.2/hadoop-1.1.2-1.x86_64.rpm
Retrieving http://ftp.cuhk.edu.hk/pub/packages/apache.org/hadoop/common/hadoop-1.1.2/hadoop-1.1.2-1.x86_64.rpm
Preparing... ########################################### [100%]
1:hadoop ########################################### [100%]
yum localinstall http://ftp.cuhk.edu.hk/pub/packages/apache.org/hadoop/common/hadoop-1.1.2/hadoop-1.1.2-1.x86_64.rpm
如果网络比较慢,可以使用Wget或axel下载后安装
wget http://ftp.cuhk.edu.hk/pub/packages/apache.org/hadoop/common/hadoop-1.1.2/hadoop-1.1.2-1.x86_64.rpm
yum localinstall hadoop-1.1.2-1.x86_64.rpm
Hadoop 用户
# cat /etc/passwd | grep Hadoop
mapred:x:202:123:Hadoop MapReduce:/tmp:/bin/bash
hdfs:x:201:123:Hadoop HDFS:/tmp:/bin/bash
-
配置/etc/hosts文件
cat >> /etc/hosts <<EOD
###############################
# Hadoop Host
###############################
#NameNode
192.168.2.10 namenode.example.com
#DataNode
192.168.2.11 datanode1.example.com
192.168.2.12 datanode2.example.com
EOD
-
生成其密钥
# ssh-keygen
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:
cc:6f:30:76:82:28:96:13:c8:e6:bc:d7:5b:2d:11:d7 root@images-upload
The key's randomart image is:
+--[ RSA 2048]----+
| |
|.. . |
|.o. . . E |
|+ o . +o |
| o= . ..S . |
| ..o. .o* |
| . . . o .o |
| . o .. |
| . |
+-----------------+
-
植入公钥证书
向DataNode节点所有的服务器植入公钥证书
ssh-copy-id root@datanode1.example.com
ssh-copy-id root@datanode2.example.com
只需要输入yes后,再输入密码即可完成公钥证书的植入。过程类似下面:
# ssh-copy-id root@datanode1.example.com
The authenticity of host 'datanode1.example.com (192.168.2.11)' can't be established.
RSA key fingerprint is f1:0b:b1:63:1a:f6:ac:a3:da:4f:14:b5:f0:cc:df:67.
Are you sure you want to continue connecting (yes/no)? yes 输入yes
Warning: Permanently added 'datanode1.example.com' (RSA) to the list of known hosts.
root@datanode1.example.com's password: 输入密码
Now try logging into the machine, with "ssh 'root@datanode1.example.com'", and check in:
.ssh/authorized_keys
to make sure we haven't added extra keys that you weren't expecting.
# ssh-copy-id root@datanode2.example.com
The authenticity of host 'datanode2.example.com (192.168.2.12)' can't be established.
RSA key fingerprint is f1:0b:b1:63:1a:f6:ac:a3:da:4f:14:b5:f0:cc:df:67.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'datanode2.example.com,192.168.2.12' (RSA) to the list of known hosts.
root@datanode2.example.com's password:
Now try logging into the machine, with "ssh 'root@datanode2.example.com'", and check in:
.ssh/authorized_keys
to make sure we haven't added extra keys that you weren't expecting.
完成后测试登陆,如果没有提示密码直接进入表示正确
# ssh root@datanode1.example.com
# exit
配置文件
core-site.xml common属性配置
hdfs-site.xml HDFS属性配置
mapred-site.xml MapReduce属性配置
hadoop-env.sh hadooop 环境变量配置
过程 141.4. Hadoop - NameNode
-
配置文件 hadoop-env.sh
将 /usr/java/default 改为 /usr
# cp hadoop-env.sh hadoop-env.sh.original
# sed -i "s:/usr/java/default:/usr:" hadoop-env.sh
-
配置文件 core-site.xml
# cp core-site.xml core-site.xml.original
<?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://namenode.example.com:9000</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/var/tmp/hadoop</value>
</property>
</configuration>
fs.default.name: NameNode的URI。hdfs://主机名:端口/
hadoop.tmp.dir: Hadoop的默认临时路径,
-
配置文件 mapred-site.xml
# cp mapred-site.xml mapred-site.xml.original
<?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>namenode.example.com:9001</value>
</property>
<property>
<name>mapred.local.dir</name>
<value>/var/tmp/hadoop</value>
</property>
</configuration>
mapred.job.tracker: JobTracker的主机和端口。
-
配置文件 hdfs-site.xml
# cp hdfs-site.xml hdfs-site.xml.original
<?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>/var/hadoop/name1</value>
<description> </description>
</property>
<property>
<name>dfs.data.dir</name>
<value>/var/hadoop/hdfs/data1</value>
<description> </description>
</property>
<property>
<name>dfs.replication</name>
<value>2</value>
</property>
</configuration>
dfs.name.dir: NameNode持久存储名字空间及事务日志的本地文件系统路径。 当这个值是一个逗号分割的目录列表时,nametable数据将会被复制到所有目录中做冗余备份。
2) dfs.data.dir是DataNode存放块数据的本地文件系统路径,逗号分割的列表。 当这个值是逗号分割的目录列表时,数据将被存储在所有目录下,通常分布在不同设备上。
3)dfs.replication是数据需要备份的数量,默认是3,如果此数大于集群的机器数会出错。
-
配置masters和slaves主从结点
备份masters与slaves配置文件
cp masters masters.original
cp slaves slaves.original
cat > /etc/hadoop/masters <<EOD
namenode.example.com
EOD
cat > /etc/hadoop/slaves <<EOD
datanode1.example.com
datanode2.example.com
EOD
-
复制配置文件
# cd /etc/hadoop/
# scp hadoop-env.sh core-site.xml mapred-site.xml hdfs-site.xml masters slaves root@datanode1.example.com:/etc/hadoop/
# scp hadoop-env.sh core-site.xml mapred-site.xml hdfs-site.xml masters slaves root@datanode2.example.com:/etc/hadoop/
控制台输出类似下面表示复制成功。
# scp hadoop-env.sh core-site.xml mapred-site.xml hdfs-site.xml masters slaves root@datanode1.example.com:/etc/hadoop/
hadoop-env.sh 100% 2116 2.1KB/s 00:00
core-site.xml 100% 412 0.4KB/s 00:00
mapred-site.xml 100% 406 0.4KB/s 00:00
hdfs-site.xml 100% 595 0.6KB/s 00:00
masters 100% 21 0.0KB/s 00:00
slaves
将 NameNode 上的配置文件复制给 DataNode
-
启动 Hadoop
创建工作目录
# mkdir /var/hadoop/
# mkdir /var/hadoop/name{1,2}
# su - hdfs -c "mkdir -p /var/hadoop/hdfs/data{1,2}"
# hadoop namenode -format
13/04/23 14:35:33 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = namenode.example.com/192.168.2.10
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 1.1.2
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.1 -r 1440782; compiled by 'hortonfo' on Thu Jan 31 02:06:43 UTC 2013
************************************************************/
Re-format filesystem in /var/hadoop/name1 ? (Y or N) Y
13/04/23 14:35:37 INFO util.GSet: VM type = 64-bit
13/04/23 14:35:37 INFO util.GSet: 2% max memory = 2.475 MB
13/04/23 14:35:37 INFO util.GSet: capacity = 2^18 = 262144 entries
13/04/23 14:35:37 INFO util.GSet: recommended=262144, actual=262144
13/04/23 14:35:37 INFO namenode.FSNamesystem: fsOwner=root
13/04/23 14:35:37 INFO namenode.FSNamesystem: supergroup=supergroup
13/04/23 14:35:37 INFO namenode.FSNamesystem: isPermissionEnabled=true
13/04/23 14:35:37 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
13/04/23 14:35:37 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
13/04/23 14:35:38 INFO namenode.NameNode: Caching file names occuring more than 10 times
13/04/23 14:35:38 INFO common.Storage: Image file of size 110 saved in 0 seconds.
13/04/23 14:35:38 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/var/hadoop/name1/current/edits
13/04/23 14:35:38 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/var/hadoop/name1/current/edits
13/04/23 14:35:38 INFO common.Storage: Storage directory /var/hadoop/name1 has been successfully formatted.
13/04/23 14:35:38 INFO common.Storage: Image file of size 110 saved in 0 seconds.
13/04/23 14:35:38 INFO namenode.FSEditLog: closing edit log: position=4, editlog= /var/hadoop/name2/current/edits
13/04/23 14:35:38 INFO namenode.FSEditLog: close success: truncate to 4, editlog= /var/hadoop/name2/current/edits
13/04/23 14:35:38 INFO common.Storage: Storage directory /var/hadoop/name2 has been successfully formatted.
13/04/23 14:35:38 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at namenode.example.com/192.168.2.10
************************************************************/
# chown hdfs:hadoop -R /var/hadoop
# /etc/init.d/hadoop-namenode start
# /etc/init.d/hadoop-datanode start
http://192.168.2.10:50070/
过程 141.5. Hadoop - DataNode
-
创建hadoop数据存储目录
mkdir /var/hadoop/
chown hdfs:hadoop -R /var/hadoop
su - hdfs -c "mkdir -p /var/hadoop/hdfs/data1"
-
启动 Hadoop
# /etc/init.d/hadoop-datanode start
141.4.4. Hadoop UI (WEB界面)
常用访问页面
1. HDFS 界面
http://hostname:50070
2. MapReduce 管理界面
http://hostname:50030
将install.log文件拷贝到分布式文件系统
hadoop fs -mkdir test
hadoop fs -put install.log test
显示文件内容
# hadoop dfs -cat test/install.log
查看目录结构
# hadoop dfs -ls
Found 1 items
drwxr-xr-x - root supergroup 0 2013-04-23 15:20 /user/root/test
[root@namenode ~]# hadoop dfs -ls test
Found 1 items
-rw-r--r-- 2 root supergroup 10278 2013-04-23 15:20 /user/root/test/install.log
原文出处:Netkiller 系列 手札
本文作者:陈景峯
转载请与作者联系,同时请务必标明文章原始出处和作者信息及本声明。