环境变量配置

  1. export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
  2. export PATH=$PATH:$JAVA_HOME/bin
  3. export HADOOP_HOME=/opt/module/hadoop
  4. export PATH=$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin
  5. export PATH

环境变量生效

  1. ~ source ~/.zshrc
  2. ~ hadoop version
  3. Hadoop 2.7.7
  4. Subversion Unknown -r c1aad84bd27cd79c3d1a7dd58202a8c3ee1ed3ac
  5. Compiled by stevel on 2018-07-18T22:47Z
  6. Compiled with protoc 2.5.0
  7. From source with checksum 792e15d20b12c74bd6f19a1fb886490
  8. This command was run using /opt/module/hadoop/share/hadoop/common/hadoop-common-2.7.7.jar

HDFS

测试Hadoop自带的wordcount

  1. hadoop cd $HADOOP_HOME
  2. hadoop mkdir wcinput
  3. hadoop cd wcinput
  4. wcinput vim wordcount.txt
  5. hello hadoop
  6. hello java
  7. hello yarn
  8. wcinput cd ../
  9. hadoop pwd
  10. /home/baxiang/opt/module/hadoop
  11. hadoop hadoop jar /opt/module/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.7.jar wordcount wcinput wcoutput
  12. hadoop cd wcoutput
  13. wcoutput ls
  14. part-r-00000 _SUCCESS
  15. wcoutput cat part-r-00000
  16. hadoop 1
  17. hello 3
  18. java 1
  19. yarn 1

修改hadoop-env.sh配置文件。echo $JAVA_HOME,修改JAVA_HOME 路径:

  1. export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64

修改core-site.xml配置文件

  1. cd /opt/module/hadoop/etc/hadoop
  2. vim core-site.xml

core-site.xml增加如下内容

  1. <configuration>
  2. <!-- 指定HDFS中NameNode的地址 -->
  3. <property>
  4. <name>fs.defaultFS</name>
  5. <value>hdfs://localhost:9000</value>
  6. </property>
  7. <!-- 指定Hadoop运行时产生文件的存储目录 -->
  8. <property>
  9. <name>hadoop.tmp.dir</name>
  10. <value>/opt/module/hadoop/data/tmp</value>
  11. </property>
  12. </configuration>

修改 hdfs-site.xml 配置信息

  1. <configuration>
  2. <!-- 指定HDFS副本的数量 -->
  3. <property>
  4. <name>dfs.replication</name>
  5. <value>1</value>
  6. </property>
  7. </configuration>

格式化命令hdfs

  1. hdfs namenode -format

格式化成功会显示如下一条信息

  1. 19/08/23 17:12:02 INFO common.Storage: Storage directory /opt/module/hadoop/data/tmp/dfs/name has been successfully formatted.

启动namenode

  1. hadoop hadoop-daemon.sh start namenode
  2. starting namenode, logging to /opt/module/hadoop/logs/hadoop-baxiang-namenode-baxiang.out

启动datanode

  1. hadoop hadoop-daemon.sh start datanode
  2. starting datanode, logging to /opt/module/hadoop/logs/hadoop-baxiang-datanode-baxiang.out

通过jps 查看启动状态

  1. hadoop jps
  2. 4338 RemoteMavenServer36
  3. 803 NameNode
  4. 1077 Jps
  5. 933 DataNode
  6. 3935 Main

前端界面查看

http://localhost:50070/dfshealth.html#tab-overview

为什么不能一直格式化NameNode,
格式化NameNode,会产生新的集群id,导致NameNode和DataNode的集群id不一致,集群找不到已往数据。所以,格式NameNode时,一定要先删除data数据和log日志,然后再格式化NameNode。

HDFS操作

  1. hadoop hadoop fs -mkdir -p /user/baxiang/input
  2. hadoop hadoop fs -put /opt/module/hadoop/wcinput/wordcount.txt /user/baxiang/input
  3. hadoop hadoop fs -ls /user/baxiang/input
  4. Found 1 items
  5. -rw-r--r-- 1 baxiang supergroup 35 2019-08-23 17:30 /user/baxiang/input/wordcount.txt
  6. hadoop hadoop fs -cat /user/baxiang/input/wordcount.txt
  7. hello hadoop
  8. hello java
  9. hello yarn

执行wordcount例子

  1. hadoop jar /opt/module/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.7.jar wordcount /user/baxiang/input/ /user/baxiang/output
  2. hadoop hadoop fs -ls /user/baxiang/output
  3. Found 2 items
  4. -rw-r--r-- 1 baxiang supergroup 0 2019-08-23 17:33 /user/baxiang/output/_SUCCESS
  5. -rw-r--r-- 1 baxiang supergroup 31 2019-08-23 17:33 /user/baxiang/output/part-r-00000
  6. hadoop hadoop fs -text /user/baxiang/output/part-r-00000
  7. hadoop 1
  8. hello 3
  9. java 1
  10. yarn 1

http://localhost:50070/explorer.html#/user/baxiang/output
Hadoop伪分布式配置 - 图1

yarn

修改yarn-site.xml

  1. <configuration>
  2. <!-- Site specific YARN configuration properties -->
  3. <!-- Reducer获取数据的方式 -->
  4. <property>
  5. <name>yarn.nodemanager.aux-services</name>
  6. <value>mapreduce_shuffle</value>
  7. </property>
  8. </configuration>

修改mapred-site.xml

  1. hadoop cp mapred-site.xml.template mapred-site.xml
  2. hadoop vim mapred-site.xml

mapred-site.xml配置信息如下

  1. <configuration>
  2. <!-- 指定MR运行在YARN上 -->
  3. <property>
  4. <name>mapreduce.framework.name</name>
  5. <value>yarn</value>
  6. </property>
  7. </configuration>

启动resourcemanager和nodemanager

  1. hadoop yarn-daemon.sh start resourcemanager
  2. starting resourcemanager, logging to /opt/module/hadoop/logs/yarn-baxiang-resourcemanager-baxiang.out
  3. hadoop yarn-daemon.sh start nodemanager
  4. starting nodemanager, logging to /opt/module/hadoop/logs/yarn-baxiang-nodemanager-baxiang.out

查看启动状况jps

  1. hadoop jps
  2. 4338 RemoteMavenServer36
  3. 803 NameNode
  4. 933 DataNode
  5. 4776 Jps
  6. 4329 ResourceManager
  7. 4621 NodeManager
  8. 3935 Main

查看界面UIhttp://localhost:8088/cluster
Hadoop伪分布式配置 - 图2
删除/user/baxiang/output文件夹

  1. hadoop hadoop fs -rm -R /user/baxiang/output
  2. 19/08/23 17:50:49 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.
  3. Deleted /user/baxiang/outp

再次执行wordcount

  1. hadoop hadoop jar /opt/module/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.7.jar wordcount /user/baxiang/input/ /user/baxiang/output

Hadoop伪分布式配置 - 图3
为了查看程序的历史运行情况,需要配置历史服务器。具体配置步骤如下
在 mapred-site.xml增加如下内容

<property>
<name>mapreduce.jobhistory.address</name>
<value>localhost:10020</value>
</property>
<!-- 历史服务器web端地址 -->
<property>
    <name>mapreduce.jobhistory.webapp.address</name>
    <value>localhost:19888</value>
</property>

启动
http://localhost:19888/jobhistory

➜  hadoop mr-jobhistory-daemon.sh start historyserver
starting historyserver, logging to /opt/module/hadoop/logs/mapred-baxiang-historyserver-baxiang.out
➜  hadoop jps
4338 RemoteMavenServer36
803 NameNode
6292 JobHistoryServer
933 DataNode
4329 ResourceManager
6348 Jps
4621 NodeManager
3935 Main

Hadoop伪分布式配置 - 图4

将程序运行日志信息上传到HDFS系统上,增加日志聚集功能好处:可以方便的查看到程序运行详情和开发调试。增加日志功能配置如下
➜ hadoop vim yarn-site.xml

<!-- 日志聚集功能使能 -->
<property>
<name>yarn.log-aggregation-enable</name>
<value>true</value>
</property>

<!-- 日志保留时间设置7天 -->
<property>
<name>yarn.log-aggregation.retain-seconds</name>
<value>604800</value>
</property>

开启日志聚集功能,需要重新启动NodeManager 、ResourceManager和HistoryManager。

➜  hadoop vim yarn-site.xml  
➜  hadoop yarn-daemon.sh stop resourcemanager
stopping resourcemanager
➜  hadoop yarn-daemon.sh stop nodemanager
stopping nodemanager
nodemanager did not stop gracefully after 5 seconds: killing with kill -9
➜  hadoop mr-jobhistory-daemon.sh stop historyserver
stopping historyserver
➜  hadoop jps
4338 RemoteMavenServer36
6978 Jps
803 NameNode
933 DataNode
3935 Main

重新启动

➜  hadoop yarn-daemon.sh start resourcemanager
starting resourcemanager, logging to /opt/module/hadoop/logs/yarn-baxiang-resourcemanager-baxiang.out
➜  hadoop yarn-daemon.sh start nodemanager
starting nodemanager, logging to /opt/module/hadoop/logs/yarn-baxiang-nodemanager-baxiang.out
➜  hadoop mr-jobhistory-daemon.sh start historyserver
starting historyserver, logging to /opt/module/hadoop/logs/mapred-baxiang-historyserver-baxiang.out
➜  hadoop jps
7345 NodeManager
4338 RemoteMavenServer36
803 NameNode
7636 Jps
933 DataNode
7579 JobHistoryServer
7053 ResourceManager
3935 Main

删除输出结果,再次执行wordcount

➜  hadoop hadoop fs -rm -R /user/baxiang/output                                                                                                       
19/08/23 18:48:28 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.
Deleted /user/baxiang/output
➜  hadoop hadoop jar /opt/module/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.7.jar wordcount /user/baxiang/input/ /user/baxiang/output

http://localhost:19888/jobhistory
Hadoop伪分布式配置 - 图5
Hadoop伪分布式配置 - 图6

错误问题汇总

/bin/bash: /bin/java: No such file or directory

https://issues.apache.org/jira/browse/HADOOP-8717
https://stackoverflow.com/questions/33968422/bin-bash-bin-java-no-such-file-or-directory

Hadoop 2.7.3 Exception from container-launch, failed due to AM Container Exit code:127
https://stackoverflow.com/questions/41906993/hadoop-2-7-3-exception-from-container-launch-failed-due-to-am-container-exit-co