[Hadoop培训笔记]03-MapReduce集群的安装与部署

注：开源力量Hadoop Development网络培训，链接：http://new.osforce.cn/course/52  个人笔记，不具参考性。

说明：
1）实验采用的是hadoop1.x，hadoop2.x的代码做一个分析
2）学习hadoop的基础知识；java基础；Linux操作基础

MapRedcue集群环境搭建
MapReduce WordCount运行
Hadoop Eclipse插件

bin目录下执行：./start-mapred.sh，启动jobtracker和tasktracker
问题：启动后使用jps命令，看不到上述tracker在运行。
原因：通过logs目录里的hadoop-michaelchen-tasktracker-mars.clustertech.com.log，查看后发现这么一条：Can not start task tracker because java.lang.IllegalArgumentException: Does not contain a valid host:port authority: local
解决方法：没有配置 mapred-site.xml，配置如下。再次启动，使用jps可以看到jobtracker和tasktracker

<property> 
<name>mapred.job.tracker</name> 
<value>localhost:9101</value> 
</property>

bin目录下创建 vim a.txt，里面写一些单词作为输入文件。

  1 hello world
  2 hello java
  3 java c++

然后将a.txt放入一个创建的input目录里，让hadoop example中的wordcount程序执行，从input目录里获取数据，结果放到output目录里

./hadoop fs -mkdir /input
./hadoop fs -put a.txt /input
./hadoop jar ../hadoop-examples-1.2.1.jar wordcount /input /output

执行的过程比较有趣，所以也贴到这里

13/12/04 12:23:07 INFO input.FileInputFormat: Total input paths to process : 1
13/12/04 12:23:07 INFO util.NativeCodeLoader: Loaded the native-hadoop library
13/12/04 12:23:07 WARN snappy.LoadSnappy: Snappy native library not loaded
13/12/04 12:23:08 INFO mapred.JobClient: Running job: job_201312041206_0001
13/12/04 12:23:09 INFO mapred.JobClient:  map 0% reduce 0%
13/12/04 12:23:22 INFO mapred.JobClient:  map 100% reduce 0%
13/12/04 12:23:34 INFO mapred.JobClient:  map 100% reduce 100%
13/12/04 12:23:38 INFO mapred.JobClient: Job complete: job_201312041206_0001
13/12/04 12:23:38 INFO mapred.JobClient: Counters: 29
13/12/04 12:23:38 INFO mapred.JobClient:   Job Counters
13/12/04 12:23:38 INFO mapred.JobClient:     Launched reduce tasks=1
13/12/04 12:23:38 INFO mapred.JobClient:     SLOTS_MILLIS_MAPS=14199
13/12/04 12:23:38 INFO mapred.JobClient:     Total time spent by all reduces waiting after reserving slots (ms)=0
13/12/04 12:23:38 INFO mapred.JobClient:     Total time spent by all maps waiting after reserving slots (ms)=0
13/12/04 12:23:38 INFO mapred.JobClient:     Launched map tasks=1
13/12/04 12:23:38 INFO mapred.JobClient:     Data-local map tasks=1
13/12/04 12:23:38 INFO mapred.JobClient:     SLOTS_MILLIS_REDUCES=12168
13/12/04 12:23:38 INFO mapred.JobClient:   File Output Format Counters
13/12/04 12:23:38 INFO mapred.JobClient:     Bytes Written=29
13/12/04 12:23:38 INFO mapred.JobClient:   FileSystemCounters
13/12/04 12:23:38 INFO mapred.JobClient:     FILE_BYTES_READ=51
13/12/04 12:23:38 INFO mapred.JobClient:     HDFS_BYTES_READ=134
13/12/04 12:23:38 INFO mapred.JobClient:     FILE_BYTES_WRITTEN=117313
13/12/04 12:23:38 INFO mapred.JobClient:     HDFS_BYTES_WRITTEN=29
13/12/04 12:23:38 INFO mapred.JobClient:   File Input Format Counters
13/12/04 12:23:38 INFO mapred.JobClient:     Bytes Read=32
13/12/04 12:23:38 INFO mapred.JobClient:   Map-Reduce Framework
13/12/04 12:23:38 INFO mapred.JobClient:     Map output materialized bytes=51
13/12/04 12:23:38 INFO mapred.JobClient:     Map input records=3
13/12/04 12:23:38 INFO mapred.JobClient:     Reduce shuffle bytes=51
13/12/04 12:23:38 INFO mapred.JobClient:     Spilled Records=8
13/12/04 12:23:38 INFO mapred.JobClient:     Map output bytes=56
13/12/04 12:23:38 INFO mapred.JobClient:     Total committed heap usage (bytes)=181141504
13/12/04 12:23:38 INFO mapred.JobClient:     CPU time spent (ms)=5400
13/12/04 12:23:38 INFO mapred.JobClient:     Combine input records=6
13/12/04 12:23:38 INFO mapred.JobClient:     SPLIT_RAW_BYTES=102
13/12/04 12:23:38 INFO mapred.JobClient:     Reduce input records=4
13/12/04 12:23:38 INFO mapred.JobClient:     Reduce input groups=4
13/12/04 12:23:38 INFO mapred.JobClient:     Combine output records=4
13/12/04 12:23:38 INFO mapred.JobClient:     Physical memory (bytes) snapshot=175915008
13/12/04 12:23:38 INFO mapred.JobClient:     Reduce output records=4
13/12/04 12:23:38 INFO mapred.JobClient:     Virtual memory (bytes) snapshot=787206144
13/12/04 12:23:38 INFO mapred.JobClient:     Map output records=6

看看创建了什么文件，使用命令 ./hadoop fs -lsr /

drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:20 /input
-rw-r--r--   1 michaelchen supergroup         32 2013-12-04 12:20 /input/a.txt
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:23 /output
-rw-r--r--   1 michaelchen supergroup          0 2013-12-04 12:23 /output/_SUCCESS
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:23 /output/_logs
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:23 /output/_logs/history
-rw-r--r--   1 michaelchen supergroup      13815 2013-12-04 12:23 /output/_logs/history/job_201312041206_0001_1386130987951_michaelchen_word+count
-rw-r--r--   1 michaelchen supergroup      49533 2013-12-04 12:23 /output/_logs/history/job_201312041206_0001_conf.xml
-rw-r--r--   1 michaelchen supergroup         29 2013-12-04 12:23 /output/part-r-00000
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 10:26 /system
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:17 /tmp
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:17 /tmp/hadoop-michaelchen
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:23 /tmp/hadoop-michaelchen/mapred
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:23 /tmp/hadoop-michaelchen/mapred/staging
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 12:23 /tmp/hadoop-michaelchen/mapred/staging/michaelchen
drwx------   - michaelchen supergroup          0 2013-12-04 12:23 /tmp/hadoop-michaelchen/mapred/staging/michaelchen/.staging
drwx------   - michaelchen supergroup          0 2013-12-04 12:23 /tmp/hadoop-michaelchen/mapred/system
-rw-------   1 michaelchen supergroup          4 2013-12-04 12:17 /tmp/hadoop-michaelchen/mapred/system/jobtracker.info
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 10:33 /user
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 10:33 /user/michaelchen
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 10:33 /user/michaelchen/archiveDir
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 10:33 /user/michaelchen/archiveDir/pack.har
-rw-r--r--   1 michaelchen supergroup          0 2013-12-04 10:33 /user/michaelchen/archiveDir/pack.har/_SUCCESS
-rw-r--r--   5 michaelchen supergroup         72 2013-12-04 10:33 /user/michaelchen/archiveDir/pack.har/_index
-rw-r--r--   5 michaelchen supergroup         22 2013-12-04 10:33 /user/michaelchen/archiveDir/pack.har/_masterindex
-rw-r--r--   1 michaelchen supergroup      15147 2013-12-04 10:33 /user/michaelchen/archiveDir/pack.har/part-0
drwxr-xr-x   - michaelchen supergroup          0 2013-12-04 10:31 /xwchen
-rw-r--r--   1 michaelchen supergroup      15147 2013-12-04 10:31 /xwchen/hadoop

分析后的结果放在这里，使用命令查看：./hadoop fs -cat /output/part-r-00000

c++     1
hello   2
java    2
world   1

Hadoop Eclipse插件

1）hadoop自0.20.x版本后不再提供现成的hadoop-eclipse插件，而是给出了源码自行编译
2）编译采用的是ant+ivy
3）URL：http://wiki.apache.org/hadoop/EclipsePlugin

编译的整个过程很是容易出问题，建议参考此链接：http://www.srccodes.com/p/article/30/build-hadoop-eclipse-plugin-jar-from-source-code-and-install-that-plugin-in-eclipse-ide

链接中注意版本号可能会有更改。

不过我编译的hadoop plugin的插件还是在eclipse中无法使用，最后用的网上下载的。。。
无法使用是出现在eclipse菜单里，show-others里编辑mapreduce路径，点new，弹不出窗口，泪奔啊～～

WordCount里用的相关Jar包依赖如下：

输入参数：hdfs://192.168.56.101:9100/input /output

注意output之前不能存在，否则报错。

其他参考视频。在1.2.1中编译成功，运行成功。

试题中的一些笔记：

• hadoop对于小文件的处理方式：Archive、CombinedInputFormat、SequenceFile、MapFile
• Apache Mesos is a cluster manager that provides efficient resource isolation and sharing across distributed applications, or frameworks.
• Borg（来自Google），YARN（来自Apache，属于Hadoop下面的一个分支，开源），Mesos（来自Twitter，开源），Torca（来自腾讯搜搜），Corona（来自Facebook，开源）一类系统被称为资源统一管理系统或者资源统一调度系统，它们是大数据时代的必然产物。
• SecondaryNamenode的作用是合并fsimage和editlogs
• Apache Tez由Hortonworks开发
• 关系型数据库与HDFS之间相互数据迁移的工具是sqoop
• hadoop2.x采用maven构建源代码