Hadoop.2.x_伪分布环境搭建

设置主机名: vi /etc/sysconfig/network # 重启系统生效(临时修改: hastname xxx;另起一个终端将会看到效果,需要注意的是: 若即将搭建Hadoop,这里起的hostname禁止使用"_")
设置静态IP/DNS: vi /etc/sysconfig/network-scripts/ifcfg-eth0(示例：修改BOOTPROTO=static;IPADDR=192.168.0.111;GATEWAY=192.168.0.1;DNS1=192.168.0.1,重启网络服务: service network restart)
设置主机映射: vi /etc/hosts (格式：IP 主机名)
设置window主机映射: 修改host文件,添加 [IP 主机名]
关闭防火墙:chkconfig iptables off/service iptables restart(临时修改: service iptables stop/start 立即生效)
关闭selinx:vi /etc/sysconfig/selinux   # 需要重启系统生效(linux的一个加强安全子系统,加强对文件的访问控制,临时关闭(放开):setenforce 0;临时开启:setenforce 1)
查看linux中是否有自带的open jdk,有则卸载,以免后期和后面安装jdk冲突而不生效(查看是否存在: java -version,如果已存在则查看java版本: rpm -qa | grep "java",卸载 rpm -e "查出来的java版本" 或 yum -y remove "查出来的java版本")
准备压缩包:
hadoop-2.5.0.tar.gz
hadoop-2.5.0-src.tar.gz(可选包,编译源码包时使用)
native-2.5.0.tar.gz(可选包,已编译好的hadoop库,可直接替换使用)
protobuf-2.5.0.tar.gz(可选包,编译源码是必备组件)
jdk-7u67-linux-x64.tar.gz(hadoop2.x要求jdk版本1.7+)
apache-maven-3.0.5-bin.tar.gz(Maven包)
repository.tar.gz(可选包,Maven仓库,在编译Hadoop源码,会用到,若不用，则在编译时会花费更长时间去下载)
eclipse-jee-kepler-SR1-linux-gtk-x86_64.tar.gz(linux下使用,编写mr程序本地测试使用)

[root@centos66-bigdata-hadoop ~]# su - liuwl
[liuwl@centos66-bigdata-hadoop ~]$ cd opt/
[liuwl@centos66-bigdata-hadoop opt]$ ls
data  files  localsrc  modules  software  workspace
---------------------------------------------------------------
上传搭建Hadoop2.x的所有tar压缩包,压缩包自备,使用上传工具
上传工具很多:filezilla,FlashFXP,Xftp,vmware-tools,notepad++...
可能会有文件夹权限问题,需要检查一下

[root@centos66-bigdata-hadoop ~]# visudo
...
liuwl   ALL=(root)      NOPASSWD:ALL
[root@centos66-bigdata-hadoop ~]# su - liuwl
[liuwl@centos66-bigdata-hadoop ~]$ sudo -l
...
User liuwl may run the following commands on this host:
    (root) NOPASSWD: ALL

[root@centos66-bigdata-hadoop ~]# su - liuwl
[liuwl@centos66-bigdata-hadoop ~]$ cd opt/
[liuwl@centos66-bigdata-hadoop opt]$ ls
data  files  localsrc  modules  software  workspace    # 文件夹随意,自己知道是装载什么的就好

[liuwl@centos66-bigdata-hadoop ~]$ vi /etc/profile
...
#JAVA_HOME
export JAVA_HOME=/opt/modules/jdk1.7.0_67
export PATH=$PATH:$JAVA_HOME/bin
[liuwl@centos66-bigdata-hadoop ~] source /etc/profile
[liuwl@centos66-bigdata-hadoop ~]$ echo $JAVA_HOME
/opt/modules/jdk1.7.0_67
[liuwl@centos66-bigdata-hadoop ~]$ java -version
java version "1.7.0_67"
Java(TM) SE Runtime Environment (build 1.7.0_67-b01)
Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

# 有兴趣的朋友可以使用lynx在终端查看doc文档,当然需要使用root用户安装lynx：yum -y instatll lynx
# 然后lynx xxx.html 退出：q-->y
[liuwl@centos66-bigdata-hadoop ~]$ cd /home/liuwl/opt/files
[liuwl@centos66-bigdata-hadoop files]$ tar -zxf hadoop-2.5.0.tar.gz -C ../modules/
[liuwl@centos66-bigdata-hadoop files]$ sudo rm -rf ../modules/hadoop-2.5.0/share/doc/

hadoop-env.sh
    export JAVA_HOME=/opt/modules/jdk1.7.0_67
mapred-env.sh
    export JAVA_HOME=/opt/modules/jdk1.7.0_67
yarn-env.sh
    export JAVA_HOME=/opt/modules/jdk1.7.0_67

core-site.xml >>
　　<!--指定namenode主机地址-->
　　　<property>
        <name>fs.defaultFS</name>
        <value>hdfs://centos66-bigdata-hadoop.com:8020</value>
     </property>
	
　　<!--指定hdfs格式化临时目录-->
     <property>
        <name>hadoop.tmp.dir</name>
        <value>/home/liuwl/opt/modules/hadoop-2.5.0/data/tmp</value>
     </property>
	
　　<!--修改外部web访问的账户，更改dr.who为liuwl(自定义)-->
　　　<property>
        <name>hadoop.http.staticuser.user</name>
        <value>liuwl</value>
     </property>

slaves >>
　　 linux_66_64.liuwl
hdfs-site.xml >>
    <!--设置系统快副本个数-->
     <property>
        <name>dfs.replication</name>
        <value>1</value>
     </property>
	
    <!--访问jar运行后的临时目录去除权限限制-->
     <property>
        <name>dfs.permissions.enabled</name>
        <value>false</value>
     </property>

[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs namenode -format
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ ls data/tmp/
dfs

 yarn-site.xml >>
    <!--告知系统resourcemanager所在机器-->
　　　<property>
	<name>yarn.resourcemanager.hostname</name>
	<value>centos66-bigdata-hadoop.com</value>
　　　</property>

　　<!--告知系统在nodemanager上运行MR程序-->
　　　<property>
	<name>yarn.nodemanager.aux-services</name>
	<value>mapreduce_shuffle</value>
     </property>
	
　　<!--启用日志聚集功能-->
　　　<property>
        <name>yarn.log-aggregation-enable</name>
        <value>true</value>
     </property>
	 
    <!--配置日志保存期限,单位为秒-->
    <property>
        <name>yarn.log-aggregation.retain-seconds</name>
        <value>108600</value>
    </property>

mapred.site.xml >>
　　<!--指定MapReduce运行在YARN上-->
    <property>
	<name>mapreduce.framework.name</name>
        <value>yarn</value>
    </property>
	  
    <!--配置historyserver指定机器-->
    <property>
        <name>mapreduce.jobhistory.address</name>
        <value>centos66-bigdata-hadoop.com:10020</value>
    </property>
	  
    <!--配置web访问historyserver-->
    <property>
        <name>mapreduce.jobhistory.webapp.address</name>
        <value>centos66-bigdata-hadoop.com:19888</value>
    </property>

[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ sbin/hadoop-daemon.sh start namenode
starting namenode, logging to /home/liuwl/opt/modules/hadoop-2.5.0/logs/hadoop-liuwl-namenode-centos66-bigdata-hadoop.com.out
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ sbin/hadoop-daemon.sh start datanode
starting datanode, logging to /home/liuwl/opt/modules/hadoop-2.5.0/logs/hadoop-liuwl-datanode-centos66-bigdata-hadoop.com.out
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ sbin/yarn-daemon.sh start resourcemanager
starting resourcemanager, logging to /home/liuwl/opt/modules/hadoop-2.5.0/logs/yarn-liuwl-resourcemanager-centos66-bigdata-hadoop.com.out
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ sbin/yarn-daemon.sh start nodemanager
starting nodemanager, logging to /home/liuwl/opt/modules/hadoop-2.5.0/logs/yarn-liuwl-nodemanager-centos66-bigdata-hadoop.com.out
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ sbin/mr-jobhistory-daemon.sh start historyserver
starting historyserver, logging to /home/liuwl/opt/modules/hadoop-2.5.0/logs/mapred-liuwl-historyserver-centos66-bigdata-hadoop.com.out
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ sbin/hadoop-daemon.sh start secondarynamenode
starting secondarynamenode, logging to /home/liuwl/opt/modules/hadoop-2.5.0/logs/hadoop-liuwl-secondarynamenode-centos66-bigdata-hadoop.com.out
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ jps
10772 NameNode
11179 NodeManager
10853 DataNode
10938 ResourceManager
11382 SecondaryNameNode
11302 JobHistoryServer
11420 Jps

[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -mkdir -p /user/liuwl/tmp
16/09/14 07:51:14 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ vi ../../data/wordcount.input
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -mkdir -p /user/liuwl/tmp/input
16/09/14 07:54:17 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -put ../../data/wordcount.input /user/liuwl/tmp/input
16/09/14 07:54:45 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -cat /user/liuwl/tmp/input/wordcount.input
16/09/14 07:55:27 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
hadoop mapreduce
yarn historyserver hadoop
mapreduce yarn
namenode datanode
datanode
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -get /user/liuwl/tmp/input/wordcount.input /opt/modules/wc.input
16/09/14 07:56:24 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
get: /opt/modules/wc.input._COPYING_ (Permission denied)
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -get /user/liuwl/tmp/input/wordcount.input ~/opt/data/wc.input
16/09/14 07:57:00 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ cat ../../data/wc.input 
hadoop mapreduce
yarn historyserver hadoop
mapreduce yarn
namenode datanode
datanode

[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/yarn jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.5.0.jar wordcount /user/liuwl/tmp/input /user/liuwl/tmp/output
16/09/14 07:59:53 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
16/09/14 07:59:55 INFO client.RMProxy: Connecting to ResourceManager at centos66-bigdata-hadoop.com/192.168.0.110:8032
16/09/14 07:59:57 INFO input.FileInputFormat: Total input paths to process : 1
16/09/14 07:59:57 INFO mapreduce.JobSubmitter: number of splits:1
16/09/14 07:59:58 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1473864360962_0001
16/09/14 07:59:59 INFO impl.YarnClientImpl: Submitted application application_1473864360962_0001
16/09/14 08:00:00 INFO mapreduce.Job: The url to track the job: http://centos66-bigdata-hadoop.com:8088/proxy/application_1473864360962_0001/
16/09/14 08:00:00 INFO mapreduce.Job: Running job: job_1473864360962_0001
16/09/14 08:00:30 INFO mapreduce.Job: Job job_1473864360962_0001 running in uber mode : false
16/09/14 08:00:30 INFO mapreduce.Job:  map 0% reduce 0%
16/09/14 08:01:19 INFO mapreduce.Job:  map 100% reduce 0%
16/09/14 08:01:47 INFO mapreduce.Job:  map 100% reduce 100%
16/09/14 08:01:49 INFO mapreduce.Job: Job job_1473864360962_0001 completed successfully
16/09/14 08:01:54 INFO mapreduce.Job: Counters: 49
	File System Counters
		FILE: Number of bytes read=96
		FILE: Number of bytes written=194473
		FILE: Number of read operations=0
		FILE: Number of large read operations=0
		FILE: Number of write operations=0
		HDFS: Number of bytes read=226
		HDFS: Number of bytes written=66
		HDFS: Number of read operations=6
		HDFS: Number of large read operations=0
		HDFS: Number of write operations=2
	Job Counters 
		Launched map tasks=1
		Launched reduce tasks=1
		Data-local map tasks=1
		Total time spent by all maps in occupied slots (ms)=48483
		Total time spent by all reduces in occupied slots (ms)=21661
		Total time spent by all map tasks (ms)=48483
		Total time spent by all reduce tasks (ms)=21661
		Total vcore-seconds taken by all map tasks=48483
		Total vcore-seconds taken by all reduce tasks=21661
		Total megabyte-seconds taken by all map tasks=49646592
		Total megabyte-seconds taken by all reduce tasks=22180864
	Map-Reduce Framework
		Map input records=5
		Map output records=10
		Map output bytes=125
		Map output materialized bytes=96
		Input split bytes=141
		Combine input records=10
		Combine output records=6
		Reduce input groups=6
		Reduce shuffle bytes=96
		Reduce input records=6
		Reduce output records=6
		Spilled Records=12
		Shuffled Maps =1
		Failed Shuffles=0
		Merged Map outputs=1
		GC time elapsed (ms)=293
		CPU time spent (ms)=2970
		Physical memory (bytes) snapshot=313458688
		Virtual memory (bytes) snapshot=1680084992
		Total committed heap usage (bytes)=136450048
	Shuffle Errors
		BAD_ID=0
		CONNECTION=0
		IO_ERROR=0
		WRONG_LENGTH=0
		WRONG_MAP=0
		WRONG_REDUCE=0
	File Input Format Counters 
		Bytes Read=85
	File Output Format Counters 
		Bytes Written=66
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -ls /user/liuwl/tmp/output
16/09/14 08:02:23 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 2 items
-rw-r--r--   1 liuwl supergroup          0 2016-09-14 08:01 /user/liuwl/tmp/output/_SUCCESS
-rw-r--r--   1 liuwl supergroup         66 2016-09-14 08:01 /user/liuwl/tmp/output/part-r-00000
[liuwl@centos66-bigdata-hadoop hadoop-2.5.0]$ bin/hdfs dfs -text /user/liuwl/tmp/output/part*
16/09/14 08:02:44 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
datanode    2
hadoop  2
historyserver   1
mapreduce   2
namenode    1
yarn    2

1> Hadoop Common:hadoop的公共类，方法，功能
2> Hadoop Distributed File System(hafs)
    hadoop 分布式 文件系统
        架构:主从架构(分工明确,namenode存储从节点信息,datanode存储具体数据)
        可靠性:
            系统块副本机制(自定义副本个数,坏块就近自动填补,定期校验副本块)
            文件系统使用SecondaryNameNode定期合并edit与影像文件
        可扩展性:
            在集群全有机器基础上可任意添加多台机器
        运行原理:
            客户端写入文件,告知namenode,namenode存储着datanode以及以前文件的所有信息,分配系统块给予客户端写入
            客户端读文件，namenode根据文件信息快速找到文件,采用就近原则,返回给用户
3> Hadoop Yarn:hadoop统一资源管理与任务调度框架
    架构:主从架构(ResourceManager与NodeManager)
    个人认为,yarn类似javaee中spring框架,作为了一个容器使用
    yarn工作流程:客户端提交一个job,ResourceManager中ApplicationManager为job通过NodeManager建立ApplicationMaster用于管理job和反馈信息，ApplicationMaster告知ApplicationManager,所需要的所有正常运行job的资源,包括cpu,内存等,ApplicationManager返回给ApplicationMaster一个container(容器),让job在该容器中运行,其他job无法争夺其中的的资源,起到很好的隔离作用,job运行完毕会将运行信息发回给ApplicationMaster,ApplicationMaster通知ApplicationManager任务运行的情况,并记录job运行历史文件,收回资源等
4> Hadoop MapReduce:MapReduce是一个任务运行工具,每一个map便会开启一个java虚拟机,在MapReduceOnYarn时每个任务通过RPC协议向ApplicationManager报告自己的状态