格式化HDFS分佈式檔案系統

hadoop namenode –format

啓動Hadoop

start-all.sh

停止Hadoop

stop-all.sh

jps命令可以看到Hadoop的所有守護行程

用hdfs dfsadmin -report 命令來檢查，能看到DataNode狀態纔是正常

可以通過Hadoop NameNode和JobTracker的Web介面來檢視叢集是否啓動成功，其存取地址如下

http://192.168.96.128:8088/cluster

NameNode爲http://192.168.96.128:50070/dfshealth.html#tab-overview

JobTracker爲http://localhost:50030/

到此僅僅是在linux上佈置成功

在eclipse上執行hdfs

很多部落格說要下載外掛hadoop-eclipse-plugin-2.6.0.jar，我下載後也放在eclipse安裝資料夾的外掛plugins下了，那頭小象始終不見出來，發現不裝外掛也可以執行wordCount，與版本有關，但是不是必須對應的，

1、下載hadoop.dll和winutils.exe

https://github.com/steveloughran/winutils/blob/master/hadoop-2.8.3/bin/hadoop.dll

winutils.exe放在hadoop-2.8.4\bin

hadoop.dll放在C:\Windows\System32

環境變數

存取hdfs時報許可權錯誤

Permission denied: user=administrator, access=WRITE,

設定環境變數

設定伺服器上的hadoop使用者，因爲執行login.login的時候呼叫了hadoop裏面的HadoopLoginModule方法，會先讀取HADOOP_USER_NAME系統環境變數，然後是java環境變數，如果再沒有就從NTUserPrincipal裏面取

設定好環境，重新啓動Eclipse

Maven中設定

<?xml version="1.0"?>

-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0">

<modelVersion>4.0.0</modelVersion>

<groupId>HadoopJar</groupId>

<artifactId>Hadoop</artifactId>

<version>0.0.1-SNAPSHOT</version>

<packaging>jar</packaging>

<name>Hadoop</name>

<url>http://maven.apache.org</url>


-<properties>

<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

<hadoop.version>2.8.4</hadoop.version>

</properties>


-<dependencies>


-<dependency>

<groupId>org.apache.hadoop</groupId>

<artifactId>hadoop-common</artifactId>

<version>${hadoop.version}</version>

</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-mapreduce-client-core -->



-<dependency>

<groupId>org.apache.hadoop</groupId>

<artifactId>hadoop-mapreduce-client-core</artifactId>

<version>${hadoop.version}</version>

</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-hdfs -->



-<dependency>

<groupId>org.apache.hadoop</groupId>

<artifactId>hadoop-hdfs</artifactId>

<version>${hadoop.version}</version>

</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-mapreduce-client-common -->



-<dependency>

<groupId>org.apache.hadoop</groupId>

<artifactId>hadoop-mapreduce-client-common</artifactId>

<version>${hadoop.version}</version>

</dependency>

<!-- https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-mapreduce-client-jobclient -->



-<dependency>

<groupId>org.apache.hadoop</groupId>

<artifactId>hadoop-mapreduce-client-jobclient</artifactId>

<version>${hadoop.version}</version>

</dependency>


-<dependency>

<groupId>junit</groupId>

<artifactId>junit</artifactId>

<version>3.8.1</version>

<scope>test</scope>

</dependency>


-<dependency>

<groupId>jdk.tools</groupId>

<artifactId>jdk.tools</artifactId>

<version>1.8</version>

<scope>system</scope>

<systemPath>D:\Java\jdk1.8.0_101\lib/tools.jar</systemPath>

</dependency>

</dependencies>


-<build>

<finalName>Hadoop</finalName>


-<plugins>


-<plugin>

<artifactId>maven-compiler-plugin</artifactId>


-<configuration>

<source>1.8</source>

<target>1.8</target>

<encoding>UTF-8</encoding>

</configuration>

</plugin>


-<plugin>

<groupId>org.apache.maven.plugins</groupId>

<artifactId>maven-resources-plugin</artifactId>


-<configuration>

<encoding>UTF-8</encoding>

</configuration>

</plugin>

</plugins>

</build>

</project>

wordCount Demo

組態檔

主機名要替換成IP

hadoop.tmp.dir /usr/local/hadoop-2.8.4/tmp Abase for other temporary directories. fs.defaultFS hdfs://192.168.96.128:9000 io.file.buffer.size 4096

執行結果

Hdfs dfs –mkdir /hi

啓動hadoop

在eclipse上執行hdfs