Hadoop伪分布式搭建

Posted by phantomVK on October 9, 2016

一、环境及配置

运行环境:Ubuntu 16.04 LTS AMD64OpenJDK 9Hadoop-1.2.1OpenSSH

Hadoop依赖JDK,请确认系统已安装JDK,具体设置请参考文章: Ubuntu安装Oracle JDK8

二、 Hadoop安装及配置

2.1 下载Hadoop

通过wget在清华大学镜像源下载Hadoop并解压到/opt

$ cd /opt
$ wget https://mirrors.tuna.tsinghua.edu.cn/apache/hadoop/common/hadoop-1.2.1/hadoop-1.2.1.tar.gz
$ tar -zxvf hadoop-1.2.1.tar.gz

2.2 配置Hadoop参数

2.2.1 配置文件路径

$ cd /opt/hadoop-1.2.1/conf

2.2.2 配置hadoop-env.sh

在文件中添加安装JDK的路径,这里用的是OpenJDK

$ vim hadoop-env.sh  

 export JAVA_HOME=/usr/lib/jvm/java-9-openjdk-amd64 

2.2.3 配置core-site.xml

$ vim core-site.xml

配置内容如下:

<configuration>
    <property>
        <name>hadoop.tmp.dir</name>
        <value>/hadoop</value>
    </property>
    <property>
        <name>dfs.name.dir</name>
        <value>/hadoop/name</value>
    </property>
    <property>
        <name>fs.default.name</name>
        <value>hdfs://localhost:9000</value>
    </property>
</configuration>

2.2.4 配置hdfs-site.xml

$ vim hdfs-site.xml

配置内容如下:

<configuration>
    <property>
        <name>dfs.data.dir</name>
        <value>/hadoop/data</value>
    </property>
</configuration>

2.2.5 配置mapred-site.xml

$ vim mapred-site.xml

配置内容如下:

<configuration>
    <property>
        <name>mapred.job.tracker</name>
        <value>localhost:9001</value>
    </property>
</configuration>

2.2.6 配置/etc/profile

$ vim /etc/profile

增加以下配置:

 export HADOOP_HOME=/opt/hadoop-1.2.1 

相同文件PATH变量中追加参数$HADOOP_HOME/bin:,保存、退出并刷新profile

$ source /etc/profile

2.3 初始化NameNode

运行命令后会自动开始格式化,最后NameNode自动关闭

$ hadoop namenode -format 
************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = mike-virtual-machine/127.0.1.1
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 = 9-internal
************************************************************/
16/06/18 11:36:16 INFO util.GSet: Computing capacity for map BlocksMap
16/06/18 11:36:16 INFO util.GSet: VM type       = 64-bit
16/06/18 11:36:16 INFO util.GSet: 2.0% max memory = 1048576000
16/06/18 11:36:16 INFO util.GSet: capacity      = 2^21 = 2097152 entries
16/06/18 11:36:16 INFO util.GSet: recommended=2097152, actual=2097152
16/06/18 11:36:17 INFO namenode.FSNamesystem: fsOwner=root
16/06/18 11:36:17 INFO namenode.FSNamesystem: supergroup=supergroup
16/06/18 11:36:17 INFO namenode.FSNamesystem: isPermissionEnabled=true
16/06/18 11:36:17 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
16/06/18 11:36:17 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
16/06/18 11:36:17 INFO namenode.FSEditLog: dfs.namenode.edits.toleration.length = 0
16/06/18 11:36:17 INFO namenode.NameNode: Caching file names occuring more than 10 times 
16/06/18 11:36:17 INFO common.Storage: Image file /hadoop/dfs/name/current/fsimage of size 110 bytes saved in 0 seconds.
16/06/18 11:36:17 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/hadoop/dfs/name/current/edits
16/06/18 11:36:17 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/hadoop/dfs/name/current/edits
16/06/18 11:36:17 INFO common.Storage: Storage directory /hadoop/dfs/name has been successfully formatted.
16/06/18 11:36:17 INFO namenode.NameNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at mike-virtual-machine/127.0.1.1
************************************************************/

三、 启动Hadoop服务

进入Hadoop目录,通过脚本启动Hadoop

$ cd /opt/hadoop-1.2.1/bin
$ ./start_all.sh

运行结果

starting namenode, logging to /opt/hadoop-1.2.1/libexec/../logs/hadoop-root-namenode-mike-virtual-machine.out
localhost: Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
root@localhost's password: 
localhost: 
localhost: starting datanode, logging to /opt/hadoop-1.2.1/libexec/../logs/hadoop-root-datanode-mike-virtual-machine.out
localhost: Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
root@localhost's password: 
localhost: 
localhost: starting secondarynamenode, logging to /opt/hadoop-1.2.1/libexec/../logs/hadoop-root-secondarynamenode-mike-virtual-machine.out
starting jobtracker, logging to /opt/hadoop-1.2.1/libexec/../logs/hadoop-root-jobtracker-mike-virtual-machine.out
localhost: Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
root@localhost's password: 
localhost: 
localhost: starting tasktracker, logging to /opt/hadoop-1.2.1/libexec/../logs/hadoop-root-tasktracker-mike-virtual-machine.out

jps查看可知Hadoop已启动

$ jps
 2531 DataNode
 2524 NameNode
 2678 SecondaryNameNode
 2778 JobTracker
 2940 TaskTracker
 3039 sun.tools.jps.Jps

四、 疑难解答

4.1 解决 /etc/profile 失效

~/.bashrc文件添加环境变量

$ cd ~
$ vim .bashrc
  export HADOOP_HOME_WARN_SUPPRESS=1
  export HADOOP_HOME=/opt/hadoop-1.2.1
  export JAVA_HOME=/usr/lib/jvm/java-9-openjdk-amd64/
  export JER_HOME=$JAVA_HOME/jre
  export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
  export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$HADOOP_HOME/bin:$PATH
$ source .bashrc

4.2 找不到配置文件

这个错误可能在使用OpenJDK时出现

Error: Config file not found: /usr/lib/jvm/java-9-openjdk-amd64/conf/management/management.properties

原因是软链接不存在,手动创建正确软链接即可

$ cd /usr/lib/jvm/java-9-openjdk-amd64
$ touch conf
$ ln -s lib conf
$ ls -la conf
 lrwxrwxrwx 1 root root 3 6月  16 17:24 conf -$ lib

4.3 HADOOP_HOME is deprecated

Warning: $HADOOP_HOME is deprecated

~/.bash_profile里增加一个环境变量抑制错误提示

export HADOOP_HOME_WARN_SUPPRESS=1

4.4 SSH无法连接

没有安装SSH服务导致

localhost: ssh: connect to host localhost port 22: Connection refused

下载openssh-server

$ ssh-agent
$ apt-get install openssh-server

配置ssh_config

$ cd /etc/ssh/ssh_config
    StrictHostKeyChecking no     # 修改为no
    UserKnownHostsFile /dev/null # 添加这行

配置sshd_config

$ cd /etc/ssh/sshd_config
    PermitRootLogin prohibit-password        # 改为 yes
    PasswordAuthentication prohibit-password # 取消注释

重启系统,开启ssh服务

$ service sshd restart
$ ssh localhost # 检查ssh服务

4.5 安装dpkg报错

多个窗口同时使用apt-get会出现此错误,避免同时使用多个窗口

.....
.....
E:Sub-process /usr/bin/dpkg returned an error code(1)

如果问题无法解决,可以尝试:

$ cd /var/lib/dpkg
$ mv info infobak
$ mkdir info
$ mv ./info/* ./infobak
$ rm -rf ./info 
$ mv ./infobak ./info