hdfs

hdfs集群配置

#核心配置参数：
    1)指定hadoop的默认文件系统为：hdfs
    2)指定hdfs的namenode节点为哪台机器
    3)指定namenode软件存储元数据的本地目录
    4)指定datanode软件存放文件块的本地目录
1.vim hadoop-env.sh 
export JAVA_HOME=/usr/local/software/jdk1.8.0_11/
2.vim core-site.xml
    #指定HDFS协议和NameNode(pengyy22)
<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://pengyy22:9000</value>
    </property>
</configuration>
3.vim hdfs-site.xml
    #指定namenode软件存储元数据的本地目录
    <property>
        <name>dfs.namenode.name.dir</name>
        <value>/usr/local/hadoop/name</value>
    </property>
    #指定datanode软件存放文件块的本地目录
    <property>
        <name>dfs.datanode.data.dir</name>
        <value>/usr/local/hadoop/data</value>
    </property>
4.scp
    #将整个hadoop目录远程复制到各自DataNode的服务器中
    scp -r hadoop-2.8.1/ pengyy42:/usr/local/software/
    scp -r hadoop-2.8.1/ pengyy43:/usr/local/software/
    scp -r hadoop-2.8.1/ pengyy44:/usr/local/software/
5.vim /etc/profile
    #配置环境变量
    #pengyy start
    JAVA_HOME=/usr/local/software/jdk1.8.0_11
    CLASSPATH=.:$JAVA_HOME/lib.tools.jar
    HADOOP_HOME=/usr/local/software/hadoop-2.8.1
    ZOOKEEPER_HOME=/usr/local/software/zookeeper
    PATH=$JAVA_HOME/bin:$PATH:$HADOOP_HOME/bin:$HADOOP_HOME/sbin:$ZOOKEEPER_HOME/bin
    export JAVA_HOME CLASSPATH HADOOP_HOME ZOOKEEPER_HOME
    #pengyy end
    source /etc/profile
6.初始化 NameNode 的元数据目录
    #初始化 namenode 的元数据存储目录 （具体生成的目录由 hdfs-site.xml 指定）
    #创建一个全新的元数据存储目录
    #生成记录元数据的文件fsimage
    #?生成集群的相关标识：如：集群id——clusterID
    hadoop namenode -format
7.启动进程
    #启动NameNode进程
    hadoop-daemon.sh start namenode
    #关闭NameNode进程
    hadoop-daemon.sh stop namenode
    #查看进程 jps
    [root@pengyy22 logs]# jps
    2984 Jps
    2907 NameNode
    #查看端口号 netstat -anp|grep 2907
    [root@pengyy22 logs]# netstat -anp|grep 2907    netstat -nltp|grep 2907
    tcp     0      0 192.168.31.22:9000      0.0.0.0:*    LISTEN      2907/java           
    tcp     0      0 0.0.0.0:50070           0.0.0.0:*    LISTEN      2907/java 
    [root@pengyy22 logs]# netstat -nltp|grep 2907
    tcp     0      0 192.168.31.22:9000      0.0.0.0:*    LISTEN      2907/java           
    tcp     0      0 0.0.0.0:50070           0.0.0.0:*    LISTEN      2907/java  
    #浏览器访问
    http://192.168.31.22:50070  或   http://pengyy22:50070
    #启动DataNode进程
    hadoop-daemon.sh start datanode
    #关闭DataNode进程
    hadoop-daemon.sh stop datanode
    [root@pengyy42 hadoop]# jps
    6038 Jps
    1515 QuorumPeerMain
    5963 DataNode
    #浏览器访问
    http://pengyy42:50075
8.批量启动脚本
    1)cd /usr/local/software/hadoop-2.8.1/etc/hadoop/
    2)vim slaves        
        pengyy22
        pengyy42
        pengyy43
        pengyy44
     3)启动、关闭
     start-dfs.sh
     stop-dfs.sh
    [root@pengyy22 hadoop-2.8.1]# start-dfs.sh 
    Starting namenodes on [pengyy22]
    pengyy22: starting namenode, logging to /usr/local/software/hadoop-2.8.1/logs/hadoop-root-namenode-pengyy22.out
    pengyy42: starting datanode, logging to /usr/local/software/hadoop-2.8.1/logs/hadoop-root-datanode-pengyy42.out
    pengyy43: starting datanode, logging to /usr/local/software/hadoop-2.8.1/logs/hadoop-root-datanode-pengyy43.out
    pengyy44: starting datanode, logging to /usr/local/software/hadoop-2.8.1/logs/hadoop-root-datanode-pengyy44.out
    pengyy22: starting datanode, logging to /usr/local/software/hadoop-2.8.1/logs/hadoop-root-datanode-pengyy22.out
    Starting secondary namenodes [0.0.0.0]
    0.0.0.0: starting secondarynamenode, logging to /usr/local/software/hadoop-2.8.1/logs/hadoop-root-secondarynamenode-pengyy22.out
    [root@pengyy22 hadoop-2.8.1]# jps
    26514 SecondaryNameNode
    26661 Jps
    26246 NameNode
    26379 DataNode
#Starting secondary namenodes [0.0.0.0]  对于 secondary namenodes 可以在 hdfs-site.xml 中指定
#以下是将 NameNode 和 SecondaryNameNode 分开指定，将 SecondaryNameNode 指定在 pengyy42 服务器上
    <property>
        <name>dfs.namenode.secondary.http-address</name>
        <value>pengyy42:50090</value>
    </property>:
 #将 hdfs-site.xml 传输到 DataNode 服务器上  $PWD : 表示当前目录
 scp hdfs-site.xml pengyy42:$PWD
 scp hdfs-site.xml pengyy43:$PWD
 scp hdfs-site.xml pengyy44:$PWD
 
 9.命令行操作hdfs
hadoop fs -ls /
hadoop fs -put /software/jdk-8u11-linux-x64.tar.gz /
hadoop fs -get /jdk-8u11-linux-x64.tar.gz 
hadoop fs -mkdir /aaa
hadoop fs -mv /jdk-8u11-linux-x64.tar.gz /aaa/
hadoop fs -ls /aaa/
hadoop fs -rm -r /aaa
hadoop fs -appendToFile qinghsu.txt /install.log
hadoop fs -tail -f /install.log
hadoop fs -cat /install.log

java操作hdfs

1.引入jar包
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.8.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-client</artifactId>
        <version>2.8.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-hdfs</artifactId>
        <version>2.8.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-mapreduce-client-core</artifactId>
        <version>2.8.1</version>
    </dependency>
    /** Missing artifact jdk.tools:jdk.tools:jar:1.8
    tools.jar包是JDK自带的，pom.xml中以来的包隐式依赖tools.jar包，而tools.jar并未在库中，
    只需要将tools.jar包添加到jdk库中即可*/
    <dependency>
         <groupId>jdk.tools</groupId>
         <artifactId>jdk.tools</artifactId>
         <version>1.8</version>
         <scope>system</scope>
         <systemPath>${JAVA_HOME}/lib/tools.jar</systemPath>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
//从hadoop上下载引出的问题   
java.lang.RuntimeException: java.io.FileNotFoundException: java.io.FileNotFoundException: HADOOP_HOME and hadoop.home.dir are unset. 
//解决方案:本地配置windows版本的hadoop   HADOOP_HOME=D:\Learn\hadoop-2.8.1

hdfs

原文：https://www.cnblogs.com/pengyy/p/11318254.html