Linux下部署Hadoop伪分布模式
Hadoop版本为1.2.1
Distribution为Fedora19并使用hadoop账号安装
第一步：配置ssh本地登录证书（虽然为伪分布模式，Hadoop依然会使用SSH进行通信）
[hadoop@promote ~]$ which ssh /usr/bin/ssh [hadoop@promote ~]$ which ssh-keygen /usr/bin/ssh-keygen [hadoop@promote ~]$ which sshd /usr/sbin/sshd [hadoop@promote ~]$ ssh-keygen -t rsa
然后一路回车
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: Passphrases do not match. Try again. 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: 2f:a9:60:c7:dc:38:8f:c7:bb:70:de:d4:39:c3:39:87 hadoop@promote.cache-dns.local The key's randomart image is: +--[ RSA 2048]----+ | | | | | | | | | S | | o o o o + | | o B.= o E . | | . o Oo+ = | | o.=o. | +-----------------+
最终将在/home/hadoop/.ssh/路径下生成私钥id_rsa和公钥id_rsa.pub
[hadoop@promote .ssh]$ cd /home/hadoop/.ssh/ [hadoop@promote .ssh]$ ls id_rsa id_rsa.pub
修改sshd服务配置文件：
[hadoop@promote .ssh]$ su root 密码： [root@promote .ssh]# vi /etc/ssh/sshd_config
启用RSA加密算法验证
RSAAuthentication yes PubkeyAuthentication yes # The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2 # but this is overridden so installations will only check .ssh/authorized_keys AuthorizedKeysFile .ssh/authorized_keys
保存并退出，然后重启sshd服务
[root@promote .ssh]# service sshd restart Redirecting to /bin/systemctl restart sshd.service
然后切换回hadoop用户，将ssh证书公钥拷贝至/home/hadoop/.ssh/authorized_keys文件中
[root@promote .ssh]# su hadoop [hadoop@promote .ssh]$ cat id_rsa.pub >> authorized_keys
修改~/.ssh/authorized_keys文件的权限为644，~/.ssh文件夹的权限为700，/home/hadoop文件夹的权限为700（权限正确是成功认证的先决条件）
[hadoop@promote .ssh]$ chmod 644 authorized_keys [hadoop@promote .ssh]$ ssh 192.168.211.129 The authenticity of host 192.168.211.129(192.168.211.129)' can't be established. RSA key fingerprint is 25:1f:be:72:7b:83:8e:c7:96:b6:71:35:fc:5d:2e:7d. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.211.129' (RSA) to the list of known hosts. Last login: Thu Feb 13 23:42:43 2014
第一次登陆将会将证书内容保存在/home/hadoop/.ssh/known_hosts文件中，以后再次登陆将不需要输入密码
[hadoop@promote .ssh]$ ssh 192.168.211.129 Last login: Thu Feb 13 23:46:04 2014 from 192.168.211.129
至此ssh证书部分配置完成
第二步：安装JDK
[hadoop@promote ~]$ java -version java version "1.7.0_25" OpenJDK Runtime Environment (fedora-2.3.10.3.fc19-i386) OpenJDK Client VM (build 23.7-b01, mixed mode)
将OpenJDK换为Oracle的Java SE
[hadoop@promote .ssh]$ cd ~ [hadoop@promote ~]$ uname -i i386
在Oracle的官网下载jdk-6u45-linux-i586.bin后上传至服务器，赋予权限并进行安装，最后删除安装包
[hadoop@promote ~]$ chmod u+x jdk-6u45-linux-i586.bin [hadoop@promote ~]$ ./jdk-6u45-linux-i586.bin [hadoop@promote ~]$ rm -rf jdk-6u45-linux-i586.bin
出现以下结果说明JDK成功安装：
[hadoop@promote ~]$ /home/hadoop/jdk1.6.0_45/bin/java -version java version "1.6.0_45" Java(TM) SE Runtime Environment (build 1.6.0_45-b06) Java HotSpot(TM) Client VM (build 20.45-b01, mixed mode, sharing)
第三步：安装Hadoop
在Hadoop官网下载hadoop-1.2.1.tar.gz并上传至服务器/home/hadoop路径下
[hadoop@promote ~]$ tar -xzf hadoop-1.2.1.tar.gz [hadoop@promote ~]$ rm -rf hadoop-1.2.1.tar.gz [hadoop@promote ~]$ cd hadoop-1.2.1/conf/ [hadoop@promote conf]$ vi hadoop-env.sh
将JAVA_HOME指向第二步安装的JDK所在目录
# The java implementation to use. Required. export JAVA_HOME=/home/hadoop/jdk1.6.0_45
保存并退出
[hadoop@promote ~]$ vi ~/.bash_profile
环境变量PATH后接上Hadoop和JDK的bin目录
...... PATH=$PATH:$HOME/.local/bin:$HOME/bin:/home/hadoop/hadoop-1.2.1/bin:/home/hadoop/jdk1.6.0_45/bin export PATH
保存并退出，退出登录并重新使用hadoop账号登录，如果出现如下结果，说明环境变量PATH设置成功
[hadoop@promote ~]$ echo $PATH /usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/hadoop/.local/bin: /home/hadoop/bin:/home/hadoop/hadoop-1.2.1/bin:/home/hadoop/jdk1.6.0_45/bin
第四步：修改Hadoop配置文件
修改core-site.xml（使用IP地址而不是主机名或localhost的好处是不需要修改/etc/hosts）：
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <configuration> <property> <name>fs.default.name</name> <value>hdfs://192.168.211.129:9000</value> </property> <property> <name>hadoop.tmp.dir</name> <value>/home/hadoop/hadooptmp</value> </property> </configuration>
修改mapred-site.xml：
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <configuration> <property> <name>mapred.job.tracker</name> <value>192.168.211.129:9001</value> </property> </configuration>
修改hdfs-site.xml：
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <configuration> <property> <name>dfs.replication</name> <value>1</value> </property> </configuration>
master中指定的SNN节点和slaves中指定的从节点位置均为本地
[hadoop@promote conf]$ cat masters 192.168.211.129 [hadoop@promote conf]$ cat slaves 192.168.211.129
第五步：初始化HDFS文件系统
特别要注意的是，Hadoop并不识别带“_”的主机名，所以如果你的主机名带有“_”，一定要进行修改，修改方式参照http://blog.csdn.net/a19881029/article/details/20485079
[hadoop@fedora ~]$ hadoop namenode -format 14/03/04 22:13:41 INFO namenode.NameNode: STARTUP_MSG: /************************************************************ STARTUP_MSG: Starting NameNode STARTUP_MSG: host = fedora/127.0.0.1 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 = 1.6.0_45 ************************************************************/ 14/03/04 22:13:42 INFO util.GSet: Computing capacity for map BlocksMap 14/03/04 22:13:42 INFO util.GSet: VM type = 32-bit 14/03/04 22:13:42 INFO util.GSet: 2.0% max memory = 1013645312 14/03/04 22:13:42 INFO util.GSet: capacity = 2^22 = 4194304 entries 14/03/04 22:13:42 INFO util.GSet: recommended=4194304, actual=4194304 14/03/04 22:13:42 INFO namenode.FSNamesystem: fsOwner=hadoop 14/03/04 22:13:42 INFO namenode.FSNamesystem: supergroup=supergroup 14/03/04 22:13:42 INFO namenode.FSNamesystem: isPermissionEnabled=true 14/03/04 22:13:42 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100 14/03/04 22:13:42 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s) 14/03/04 22:13:42 INFO namenode.FSEditLog: dfs.namenode.edits.toleration.length = 0 14/03/04 22:13:42 INFO namenode.NameNode: Caching file names occuring more than 10 times 14/03/04 22:13:53 INFO common.Storage: Image file /tmp/hadoop-hadoop/dfs/name/ current/fsimage of size 112 bytes saved in 0 seconds. 14/03/04 22:13:53 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/tmp/hadoop-hadoop/dfs/name/current/edits 14/03/04 22:13:53 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/tmp/hadoop-hadoop/dfs/name/current/edits 14/03/04 22:13:53 INFO common.Storage: Storage directory /tmp/hadoop-hadoop/dfs/name has been successfully formatted. 14/03/04 22:13:53 INFO namenode.NameNode: SHUTDOWN_MSG: /************************************************************ SHUTDOWN_MSG: Shutting down NameNode at fedora/127.0.0.1 ************************************************************/
第六步：启动Hadoop
[hadoop@fedora logs]$ start-all.sh starting namenode, logging to /home/hadoop/hadoop-1.2.1/libexec/ ../logs/hadoop-hadoop-namenode-fedora.out localhost: starting datanode, logging to /home/hadoop/hadoop-1.2.1/libexec/ ../logs/hadoop-hadoop-datanode-fedora.out localhost: starting secondarynamenode, logging to /home/hadoop/hadoop-1.2.1/libexec/ ../logs/hadoop-hadoop-secondarynamenode-fedora.out starting jobtracker, logging to /home/hadoop/hadoop-1.2.1/libexec/ ../logs/hadoop-hadoop-jobtracker-fedora.out localhost: starting tasktracker, logging to /home/hadoop/hadoop-1.2.1/libexec/ ../logs/hadoop-hadoop-tasktracker-fedora.out hadoop@fedora logs]$ jps 2099 SecondaryNameNode 2184 JobTracker 1976 DataNode 2365 Jps 1877 NameNode 2289 TaskTracker
可以看到所有Hadoop守护进程均已启动
再看看日志文件中有没有报错，如果没有报错，说明Hadoop已经启动成功了
[hadoop@fedora hadoop]$ hadoop dfsadmin -report Configured Capacity: 39474135040 (36.76 GB) Present Capacity: 33661652992 (31.35 GB) DFS Remaining: 33661612032 (31.35 GB) DFS Used: 40960 (40 KB) DFS Used%: 0% Under replicated blocks: 0 Blocks with corrupt replicas: 0 Missing blocks: 0 ------------------------------------------------- Datanodes available: 1 (1 total, 0 dead) Name: 192.168.211.129:50010 Decommission Status : Normal Configured Capacity: 39474135040 (36.76 GB) DFS Used: 40960 (40 KB) Non DFS Used: 5812482048 (5.41 GB) DFS Remaining: 33661612032(31.35 GB) DFS Used%: 0% DFS Remaining%: 85.28% Last contact: Thu Mar 06 09:48:17 CST 2014
尝试执行Map/Reduce任务时也是没问题的
