完全分布式安装Hadoop

2014/09/02 19:24
阅读数 141

hadoop学习笔记之--完全分布模式安装

  Hadoop完全分布式模式安装步骤

  Hadoop模式介绍

  单机模式:安装简单,几乎不用作任何配置,但仅限于调试用途

  伪分布模式:在单节点上同时启动namenode、datanode、jobtracker、tasktracker、secondary namenode等5个进程,模拟分布式运行的各个节点

  完全分布式模式:正常的Hadoop集群,由多个各司其职的节点构成

  安装环境

  操作平台:vmware2

  操作系统:oracle linux 5.6

  软件版本:hadoop-0.22.0,jdk-6u18

  集群架构:3 node,master node(gc),slave node(rac1,rac2)

  安装步骤

  1.        下载Hadoop和jdk:

  如:hadoop-0.22.0

  694x223

  2.        配置hosts文件

  所有的节点(gc,rac1,rac2)都修改/etc/hosts,使彼此之间都能把主机名解析为ip

  [root@gc ~]$ cat /etc/hosts

  # Do not remove the following line, or various programs

  # that require network functionality will fail.

  127.0.0.1               localhost.localdomain localhost

  ::1             localhost6.localdomain6 localhost6

  192.168.2.101           rac1.localdomain rac1

  192.168.2.102           rac2.localdomain rac2

  192.168.2.100           gc.localdomain gc

  3.        建立hadoop运行账号

  在所有的节点创建hadoop运行账号

  [root@gc ~]# groupadd hadoop

  [root@gc ~]# useradd -g hadoop grid --注意此处一定要指定分组,不然可能会不能建立互信

  [root@gc ~]# id grid

  uid=501(grid) gid=54326(hadoop) groups=54326(hadoop)

  [root@gc ~]# passwd grid

  Changing password for user grid.

  New UNIX password:

  BAD PASSWORD: it is too short

  Retype new UNIX password:

  passwd: all authentication tokens updated successfully.

  4.        配置ssh免密码连入

  注意要以hadoop用户登录,在hadoop用户的主目录下进行操作。

  每个节点做下面相同的操作

  [hadoop@gc ~]$ ssh-keygen -t rsa

  Generating public/private rsa key pair.

  Enter file in which to save the key (/home/hadoop/.ssh/id_rsa):

  Created directory '/home/hadoop/.ssh'.

  Enter passphrase (empty for no passphrase):

  Enter same passphrase again:

  Your identification has been saved in /home/hadoop/.ssh/id_rsa.

  Your public key has been saved in /home/hadoop/.ssh/id_rsa.pub.

  The key fingerprint is:

  54:80:fd:77:6b:87:97:ce:0f:32:34:43:d1:d2:c2:0d hadoop@gc.localdomain

  [hadoop@gc ~]$ cd .ssh

  [hadoop@gc .ssh]$ ls

  id_rsa  id_rsa.pub

  把各个节点的authorized_keys的内容互相拷贝加入到对方的此文件中,然后就可以免密码彼此ssh连入。

  在其中一节点(gc)节点就可完成操作

  [hadoop@gc .ssh]$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

  [hadoop@gc .ssh]$ ssh rac1 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

  The authenticity of host 'rac1 (192.168.2.101)' can't be established.

  RSA key fingerprint is 19:48:e0:0a:37:e1:2a:d5:ba:c8:7e:1b:37:c6:2f:0e.

  Are you sure you want to continue connecting (yes/no)  yes

  Warning: Permanently added 'rac1,192.168.2.101' (RSA) to the list of known hosts.

  hadoop@rac1's password:

  [hadoop@gc .ssh]$ ssh rac2 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

  The authenticity of host 'rac2 (192.168.2.102)' can't be established.

  RSA key fingerprint is 19:48:e0:0a:37:e1:2a:d5:ba:c8:7e:1b:37:c6:2f:0e.

  Are you sure you want to continue connecting (yes/no)  yes

  Warning: Permanently added 'rac2,192.168.2.102' (RSA) to the list of known hosts.

  hadoop@rac2's password:

  [hadoop@gc .ssh]$ scp ~/.ssh/authorized_keys rac1:~/.ssh/authorized_keys

  hadoop@rac1's password:

  authorized_keys                                                                                                            100% 1213     1.2KB/s   00:00   

  [hadoop@gc .ssh]$ scp ~/.ssh/authorized_keys rac2:~/.ssh/authorized_keys

  hadoop@rac2's password:

  authorized_keys                                                                                                            100% 1213     1.2KB/s   00:00   

  [hadoop@gc .ssh]$ ll

  总计 16

  -rw-rw-r-- 1 hadoop hadoop 1213 10-30 09:18 authorized_keys

  -rw------- 1 hadoop hadoop 1675 10-30 09:05 id_rsa

  -rw-r--r-- 1 hadoop hadoop  403 10-30 09:05 id_rsa.pub

  --分别测试连接

  [grid@gc .ssh]$ ssh rac1 date

  2012年 11月 18日星期日 01:35:39 CST

  [grid@gc .ssh]$ ssh rac2 date

  2012年 10月 30日星期二 09:52:46 CST

  --可以看到这步和配置oracle RAC中使用 SSH 建立用户等效性步骤是一样的。

  5.        解压hadoop安装包

  --可先一某节点解压配置文件

  [grid@gc ~]$ ll

  总计 43580

  -rw-r--r-- 1 grid hadoop 44575568 2012-11-19 hadoop-0.20.2.tar.gz

  [grid@gc ~]$ tar xzvf /home/grid/hadoop-0.20.2.tar.gz

  [grid@gc ~]$ ll

  总计 43584

  drwxr-xr-x 12 grid hadoop     4096 2010-02-19 hadoop-0.20.2

  -rw-r--r--  1 grid hadoop 44575568 2012-11-19 hadoop-0.20.2.tar.gz

  --在各节点安装jdk

  [root@gc ~]# ./jdk-6u18-linux-x64-rpm.bin

  6.         Hadoop配置有关文件

  595x432

  n       配置hadoop-env.sh

  [root@gc conf]# pwd

  /root/hadoop-0.20.2/conf

  --修改jdk安装路径

  [root@gc conf]vi hadoop-env.sh

  export JAVA_HOME=/usr/java/jdk1.6.0_18

  n       配置namenode,修改site文件

  --修改core-site.xml文件

  [gird@gc conf]# vi 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://192.168.2.100:9000</value> --注意完全分布模式此地一定要用IP,下同

  </property>

  </configuration>

  注:fs.default.name NameNode的IP地址和端口

  --修改hdfs-site.xml文件

  [gird@gc conf]# vi 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.data.dir</name>

  <value>/home/grid/hadoop-0.20.2/data</value> --注意此目录必需已经创建并能读写

  </property>

  <property>

  <name>dfs.replication</name>

  <value>2</value>

  </property>

  </configuration>

  hdfs-site.xml文件中常用配置参数:

  732x418

  --修改mapred-site.xml文件

  [gird@gc conf]# vi mapred-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>mapred.job.tracker</name>

  <value>192.168.2.100:9001</value>

  </property>

  </configuration>

  mapred-site.xml文件中常用配置参数

  673x448

  n       配置masters和slaves文件

  [grid@gc conf]$ vi masters

  gc

  [grid@gc conf]$ vi slaves

  rac1

  rac2

  n       向各节点复制hadoop

  --把gc主机上面hadoop配置好文件分别copy到各节点

  --注意:复制到其它的节点后配置文件中要修改为此节点的IP

  [grid@gc conf]$ scp -r hadoop-0.20.2 rac1:/home/grid/

  [grid@gc conf]$ scp -r hadoop-0.20.2 rac2:/home/grid/

  7.         格式化namenode

  --分别在各节点进行格式化

  [grid@rac2 bin]$ pwd

  /home/grid/hadoop-0.20.2/bin

  [grid@gc bin]$ ./hadoop namenode –format

  12/10/31 08:03:31 INFO namenode.NameNode: STARTUP_MSG:

  /************************************************************

  STARTUP_MSG: Starting NameNode

  STARTUP_MSG:   host = gc.localdomain/192.168.2.100

  STARTUP_MSG:   args = [-format]

  STARTUP_MSG:   version = 0.20.2

  STARTUP_MSG:   build = ; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010

  ************************************************************/

  12/10/31 08:03:31 INFO namenode.FSNamesystem: fsOwner=grid,hadoop

  12/10/31 08:03:31 INFO namenode.FSNamesystem: supergroup=supergroup

  12/10/31 08:03:31 INFO namenode.FSNamesystem: isPermissionEnabled=true

  12/10/31 08:03:32 INFO common.Storage: Image file of size 94 saved in 0 seconds.

  12/10/31 08:03:32 INFO common.Storage: Storage directory /tmp/hadoop-grid/dfs/name has been successfully formatted.

  12/10/31 08:03:32 INFO namenode.NameNode: SHUTDOWN_MSG:

  /************************************************************

  SHUTDOWN_MSG: Shutting down NameNode at gc.localdomain/192.168.2.100

  ************************************************************/

  8.         启动hadoop

  --在master节点启动hadoop守护进程

  [grid@gc bin]$ pwd

  /home/grid/hadoop-0.20.2/bin

  [grid@gc bin]$ ./start-all.sh

  starting namenode, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-namenode-gc.localdomain.out

  rac2: starting datanode, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-datanode-rac2.localdomain.out

  rac1: starting datanode, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-datanode-rac1.localdomain.out

  The authenticity of host 'gc (192.168.2.100)' can't be established.

  RSA key fingerprint is 8e:47:42:44:bd:e2:28:64:10:40:8e:b5:72:f9:6c:82.

  Are you sure you want to continue connecting (yes/no)  yes

  gc: Warning: Permanently added 'gc,192.168.2.100' (RSA) to the list of known hosts.

  gc: starting secondarynamenode, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-secondarynamenode-gc.localdomain.out

  starting jobtracker, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-jobtracker-gc.localdomain.out

  rac2: starting tasktracker, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-tasktracker-rac2.localdomain.out

  rac1: starting tasktracker, logging to /home/grid/hadoop-0.20.2/bin/../logs/hadoop-grid-tasktracker-rac1.localdomain.out

  9.        用jps检验各后台进程是否成功启动

  --在master节点查看后台进程

  [grid@gc bin]$ /usr/java/jdk1.6.0_18/bin/jps

  27462 NameNode

  29012 Jps

  27672 JobTracker

  27607 SecondaryNameNode

  --在slave节点查看后台进程

  [grid@rac1 conf]$ /usr/java/jdk1.6.0_18/bin/jps

  16722 Jps

  16672 TaskTracker

  16577 DataNode

  [grid@rac2 conf]$ /usr/java/jdk1.6.0_18/bin/jps

  31451 DataNode

  31547 TaskTracker

  31608 Jps

  10.     安装过程中遇到的问题

  1)        Ssh不能建立互信

  建用户时不指定分组,Ssh不能建立互信,如下的步骤

  [root@gc ~]# useradd grid

  [root@gc ~]# passwd grid

  解决:

  创建新的用户组,创建用户时并指定此用户组。

  [root@gc ~]# groupadd hadoop

  [root@gc ~]# useradd -g hadoop grid

  [root@gc ~]# id grid

  uid=501(grid) gid=54326(hadoop) groups=54326(hadoop)

  [root@gc ~]# passwd grid

  2)        启动hadoop后,slave节点没有datanode进程

  现象:

  在master节点启动hadoop后,master节点进程正常,但slave节点没有datanode进程。

  --Master节点正常

  [grid@gc bin]$ /usr/java/jdk1.6.0_18/bin/jps
29843 Jps
29703 JobTracker
29634 SecondaryNameNode
29485 NameNode

--此时再在两slave节点查看进程,发现还是没有datanode进程
[grid@rac1 bin]$ /usr/java/jdk1.6.0_18/bin/jps
5528 Jps
3213 TaskTracker

[grid@rac2 bin]$ /usr/java/jdk1.6.0_18/bin/jps
30518 TaskTracker
30623 Jps

  原因:

  --回头查看在master节点启动hadoop时的输出日志,在slave节点找到启动datanode进程的日志

  [grid@rac2 logs]$ pwd

  /home/grid/hadoop-0.20.2/logs

  [grid@rac1 logs]$ more hadoop-grid-datanode-rac1.localdomain.log

  /************************************************************

  STARTUP_MSG: Starting DataNode

  STARTUP_MSG:   host = rac1.localdomain/192.168.2.101

  STARTUP_MSG:   args = []

  STARTUP_MSG:   version = 0.20.2

  STARTUP_MSG:   build = ; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010

  ************************************************************/

  2012-11-18 07:43:33,513 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Invalid directory in dfs.data.dir: can not create directory: /usr/hadoop-0.20.2/data

  2012-11-18 07:43:33,513 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: All directories in dfs.data.dir are invalid.

  2012-11-18 07:43:33,571 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:

  /************************************************************

  SHUTDOWN_MSG: Shutting down DataNode at rac1.localdomain/192.168.2.101

  ************************************************************/

  --发现是hdfs-site.xml配置文件的目录data目录没有创建

  解决:

  在各节点创建hdfs的data目录,并修改hdfs-site.xml配置文件参数

  [grid@gc ~]# mkdir -p /home/grid/hadoop-0.20.2/data

  [grid@gc conf]# vi 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.data.dir</name>

  <value>/home/grid/hadoop-0.20.2/data</value> --注意此目录必需已经创建并能读写

  </property>

  <property>

  <name>dfs.replication</name>

  <value>2</value>

  </property>

  </configuration>

  --重新启动hadoop,slave进程正常

  [grid@gc bin]$ ./stop-all.sh

  [grid@gc bin]$ ./start-all.sh


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