實作二： HDFS 指令操作練習

前言

• 此部份接續實做一

Content 1. 基本操作

1.1 瀏覽你HDFS目錄

/opt/hadoop$ bin/hadoop fs -ls

1.2 上傳資料到HDFS目錄

• 上傳

  /opt/hadoop$ bin/hadoop fs -put conf input
  

• 檢查

  /opt/hadoop$ bin/hadoop fs -ls
  /opt/hadoop$ bin/hadoop fs -ls input
  

1.3 下載HDFS的資料到本地目錄

• 下載

  /opt/hadoop$ bin/hadoop fs -get input fromHDFS
  

• 檢查

  /opt/hadoop$ ls -al | grep fromHDFS
  /opt/hadoop$ ls -al fromHDFS
  

1.4 刪除檔案

/opt/hadoop$ bin/hadoop fs -ls input
/opt/hadoop$ bin/hadoop fs -rm input/masters

1.5 直接看檔案

/opt/hadoop$ bin/hadoop fs -ls input
/opt/hadoop$ bin/hadoop fs -cat input/slaves

1.6 更多指令操作

hadooper@vPro:/opt/hadoop$ bin/hadoop fs 

Usage: java FsShell

           [-ls <path>]

           [-lsr <path>]

           [-du <path>]

           [-dus <path>]

           [-count[-q] <path>]

           [-mv <src> <dst>]

           [-cp <src> <dst>]

           [-rm <path>]

           [-rmr <path>]

           [-expunge]

           [-put <localsrc> ... <dst>]

           [-copyFromLocal <localsrc> ... <dst>]

           [-moveFromLocal <localsrc> ... <dst>]

           [-get [-ignoreCrc] [-crc] <src> <localdst>]

           [-getmerge <src> <localdst> [addnl]]

           [-cat <src>]

           [-text <src>]

           [-copyToLocal [-ignoreCrc] [-crc] <src> <localdst>]

           [-moveToLocal [-crc] <src> <localdst>]

           [-mkdir <path>]

           [-setrep [-R] [-w] <rep> <path/file>]

           [-touchz <path>]

           [-test -[ezd] <path>]

           [-stat [format] <path>]

           [-tail [-f] <file>]

           [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]

           [-chown [-R] [OWNER][:[GROUP]] PATH...]

           [-chgrp [-R] GROUP PATH...]

           [-help [cmd]]



Generic options supported are

-conf <configuration file>     specify an application configuration file

-D <property=value>            use value for given property

-fs <local|namenode:port>      specify a namenode

-jt <local|jobtracker:port>    specify a job tracker

-files <comma separated list of files>    specify comma separated files to be copied to the map reduce cluster

-libjars <comma separated list of jars>    specify comma separated jar files to include in the classpath.

-archives <comma separated list of archives>    specify comma separated archives to be unarchived on the compute machines.



The general command line syntax is

bin/hadoop command [genericOptions] [commandOptions]

1.7 自我練習

• 刪除在 hdfs 內的一整個的資料夾 input

Content 2. Hadoop 運算命令

2.1 Hadoop運算命令 grep

• grep 這個命令是擷取文件裡面特定的字元，在Hadoop example中此指令可以擷取文件中有此指定文字的字串，並作計數統計

/opt/hadoop$ bin/hadoop jar hadoop-*-examples.jar grep input grep_output 'dfs[a-z.]+' 

運作的畫面如下：

09/03/24 12:33:45 INFO mapred.FileInputFormat: Total input paths to process : 9

09/03/24 12:33:45 INFO mapred.FileInputFormat: Total input paths to process : 9

09/03/24 12:33:45 INFO mapred.JobClient: Running job: job_200903232025_0003

09/03/24 12:33:46 INFO mapred.JobClient:  map 0% reduce 0%

09/03/24 12:33:47 INFO mapred.JobClient:  map 10% reduce 0%

09/03/24 12:33:49 INFO mapred.JobClient:  map 20% reduce 0%

09/03/24 12:33:51 INFO mapred.JobClient:  map 30% reduce 0%

09/03/24 12:33:52 INFO mapred.JobClient:  map 40% reduce 0%

09/03/24 12:33:54 INFO mapred.JobClient:  map 50% reduce 0%

09/03/24 12:33:55 INFO mapred.JobClient:  map 60% reduce 0%

09/03/24 12:33:57 INFO mapred.JobClient:  map 70% reduce 0%

09/03/24 12:33:59 INFO mapred.JobClient:  map 80% reduce 0%

09/03/24 12:34:00 INFO mapred.JobClient:  map 90% reduce 0%

09/03/24 12:34:02 INFO mapred.JobClient:  map 100% reduce 0%

09/03/24 12:34:10 INFO mapred.JobClient:  map 100% reduce 10%

09/03/24 12:34:12 INFO mapred.JobClient:  map 100% reduce 13%

09/03/24 12:34:15 INFO mapred.JobClient:  map 100% reduce 20%

09/03/24 12:34:20 INFO mapred.JobClient:  map 100% reduce 23%

09/03/24 12:34:22 INFO mapred.JobClient: Job complete: job_200903232025_0003

09/03/24 12:34:22 INFO mapred.JobClient: Counters: 16

09/03/24 12:34:22 INFO mapred.JobClient:   File Systems

09/03/24 12:34:22 INFO mapred.JobClient:     HDFS bytes read=48245

09/03/24 12:34:22 INFO mapred.JobClient:     HDFS bytes written=1907

09/03/24 12:34:22 INFO mapred.JobClient:     Local bytes read=1549

09/03/24 12:34:22 INFO mapred.JobClient:     Local bytes written=3584

09/03/24 12:34:22 INFO mapred.JobClient:   Job Counters 

......

• 接著查看結果

   /opt/hadoop$ bin/hadoop fs -ls grep_output
   /opt/hadoop$ bin/hadoop fs -cat grep_output/part-00000 
  

  結果如下

  3	dfs.class
  
  3	dfs.
  
  2	dfs.period
  
  1	dfs.http.address
  
  1	dfs.balance.bandwidth
  
  1	dfs.block.size
  
  1	dfs.blockreport.initial
  
  1	dfs.blockreport.interval
  
  1	dfs.client.block.write.retries
  
  1	dfs.client.buffer.dir
  
  1	dfs.data.dir
  
  1	dfs.datanode.address
  
  1	dfs.datanode.dns.interface
  
  1	dfs.datanode.dns.nameserver
  
  1	dfs.datanode.du.pct
  
  1	dfs.datanode.du.reserved
  
  1	dfs.datanode.handler.count
  
  1	dfs.datanode.http.address
  
  1	dfs.datanode.https.address
  
  1	dfs.datanode.ipc.address
  
  1	dfs.default.chunk.view.size
  
  1	dfs.df.interval
  
  1	dfs.file
  
  1	dfs.heartbeat.interval
  
  1	dfs.hosts
  
  1	dfs.hosts.exclude
  
  1	dfs.https.address
  
  1	dfs.impl
  
  1	dfs.max.objects
  
  1	dfs.name.dir
  
  1	dfs.namenode.decommission.interval
  
  1	dfs.namenode.decommission.interval.
  
  1	dfs.namenode.decommission.nodes.per.interval
  
  1	dfs.namenode.handler.count
  
  1	dfs.namenode.logging.level
  
  1	dfs.permissions
  
  1	dfs.permissions.supergroup
  
  1	dfs.replication
  
  1	dfs.replication.consider
  
  1	dfs.replication.interval
  
  1	dfs.replication.max
  
  1	dfs.replication.min
  
  1	dfs.replication.min.
  
  1	dfs.safemode.extension
  
  1	dfs.safemode.threshold.pct
  
  1	dfs.secondary.http.address
  
  1	dfs.servers
  
  1	dfs.web.ugi
  
  1	dfsmetrics.log
  
  
  

2.2 Hadoop運算命令 WordCount

• 如名稱，WordCount會對所有的字作字數統計，並且從a-z作排列

/opt/hadoop$ bin/hadoop jar hadoop-*-examples.jar wordcount input wc_output

檢查輸出結果的方法同2.1的方法

2.3 更多運算命令

可執行的指令一覽表：

aggregatewordcount	An Aggregate based map/reduce program that counts the words in the input files.
aggregatewordhist	An Aggregate based map/reduce program that computes the histogram of the words in the input files.
grep	A map/reduce program that counts the matches of a regex in the input.
join	A job that effects a join over sorted, equally partitioned datasets
multifilewc	A job that counts words from several files.
pentomino	A map/reduce tile laying program to find solutions to pentomino problems.
pi	A map/reduce program that estimates Pi using monte-carlo method.
randomtextwriter	A map/reduce program that writes 10GB of random textual data per node.
randomwriter	A map/reduce program that writes 10GB of random data per node.
sleep	A job that sleeps at each map and reduce task.
sort	A map/reduce program that sorts the data written by the random writer.
sudoku	A sudoku solver.
wordcount	A map/reduce program that counts the words in the input files.

請參考 ​org.apache.hadoop.examples

2.4 練習

Content 3. 使用網頁Gui瀏覽資訊

• ​Map/Reduce Administration
• ​NameNode

3.1 練習

• 用網頁秀出你在 wordcount練習的輸出結果