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]

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

RandomTextWriter This program uses map/reduce to just run a distributed job where there is no interaction between the tasks and each task writes a large unsorted random sequence of words.To run: bin/hadoop jar hadoop-${version}-examples.jar randomtextwriter [-outFormat output format class] output RandomWriter This program uses map/reduce to just run a distributed job where there is no interaction between the tasks and each task write a large unsorted random binary sequence file of BytesWritable.To run: bin/hadoop jar hadoop-${version}-examples.jar randomwriter [-outFormat output format class] output Sort<K,V> This is the trivial map/reduce program that does absolutely nothing other than use the framework to fragment and sort the input values.To run: bin/hadoop jar build/hadoop-examples.jar sort [-m maps] [-r reduces] [-inFormat input format class] [-outFormat output format class] [-outKey output key class] [-outValue output value class] [-totalOrder pcnt num samples max splits] in-dir out-dir WordCount This is an example Hadoop Map/Reduce application.

Content 3. 使用網頁Gui瀏覽資訊

• ​Map/Reduce Administration
• ​NameNode

Content 4. 練習

• 刪除在 hdfs 內的一整個的資料夾 input
• 用網頁秀出你在 wordcount練習的輸出結果