wiki:NCTU110329/Lab4

Version 3 (modified by jazz, 10 years ago) (diff)

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實作四 Lab 4

HDFS Shell操作練習
HDFS Shell in practice
  • 以下練習,請連線至 hadoop.nchc.org.tw 操作。

Content 1: HDFS Shell 基本操作

Content 1: Basic HDFS Shell Commands

1.1 瀏覽你HDFS目錄

1.1 Browsing Your HDFS Folder

~$ hadoop fs -ls
~$ hadoop fs -lsr

1.2 上傳資料到 HDFS 目錄

1.2 Upload Files or Folder to HDFS

  • 上傳 Upload
~$ hadoop fs -put conf input
  • 檢查 Check
~$ hadoop fs -ls
~$ hadoop fs -ls input

1.3 下載 HDFS 的資料到本地目錄

1.3 Download HDFS Files or Folder to Local

  • 下載 Download
~$ hadoop fs -get input fromHDFS
  • 檢查 Check
~$ ls -al | grep fromHDFS
~$ ls -al fromHDFS

1.4 刪除檔案

1.4 Remove Files or Folder

~$ hadoop fs -ls input
~$ hadoop fs -rm input/masters

1.5 直接看檔案

1.5 Browse Files Directly

~$ hadoop fs -ls input
~$ hadoop fs -cat input/slaves

1.6 更多指令操作

1.6 More Commands -- Help message

hXXXX@vPro:~$ 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
hadoop command [genericOptions] [commandOptions]

Content 2: 使用網頁 GUI 瀏覽資訊

Content 2: User Web GUI to browse HDFS

Content 3: 更多 HDFS Shell 的用法

Content 3: More about HDFS Shell

  • hadoop fs <args> ,下面則列出 <args> 的用法
    Following are the examples of hadoop fs related commands.
  • 以下操作預設的目錄在 /user/<$username>/ 下
    By default, your working directory will be at /user/<$username>/.
    $ hadoop fs -ls input
    Found 4 items
    -rw-r--r--   2 hXXXX supergroup  115045564 2009-04-02 11:51 /user/hXXXX/input/1.txt
    -rw-r--r--   2 hXXXX supergroup     987864 2009-04-02 11:51 /user/hXXXX/input/2.txt
    -rw-r--r--   2 hXXXX supergroup    1573048 2009-04-02 11:51 /user/hXXXX/input/3.txt
    -rw-r--r--   2 hXXXX supergroup   25844527 2009-04-02 11:51 /user/hXXXX/input/4.txt
    
  • 完整的路徑則是 hdfs://node:port/path 如:
    Or you have to give a absolute path, such as hdfs://node:port/path
    $ hadoop fs -ls hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input
    Found 4 items
    -rw-r--r--   2 hXXXX supergroup  115045564 2009-04-02 11:51 /user/hXXXX/input/1.txt
    -rw-r--r--   2 hXXXX supergroup     987864 2009-04-02 11:51 /user/hXXXX/input/2.txt
    -rw-r--r--   2 hXXXX supergroup    1573048 2009-04-02 11:51 /user/hXXXX/input/3.txt
    -rw-r--r--   2 hXXXX supergroup   25844527 2009-04-02 11:51 /user/hXXXX/input/4.txt
    

-cat

  • 將路徑指定文件的內容輸出到 STDOUT
    Print given file content to STDOUT
    $ hadoop fs -cat quota/hadoop-env.sh
    

-chgrp

  • 改變文件所屬的組
    Change owner group of given file or folder
    $ hadoop fs -chgrp -R hXXXX own
    

-chmod

  • 改變文件的權限
    Change read and write permission of given file or folder
    $ hadoop fs -chmod -R 755 own
    

-chown

  • 改變文件的擁有者
    Change owner of given file or folder
    $ hadoop fs -chown -R hXXXX own
    

-copyFromLocal, -put

  • 從 local 放檔案到 hdfs
    Both commands will copy given file or folder from local to HDFS
    $ hadoop fs -put input dfs_input
    

-copyToLocal, -get

  • 把hdfs上得檔案下載到 local
    Both commands will copy given file or folder from HDFS to local
    $ hadoop fs -get dfs_input input1
    

-cp

  • 將文件從 hdfs 原本路徑複製到 hdfs 目標路徑
    Copy given file or folder from HDFS source path to HDFS target path
    $ hadoop fs -cp own hXXXX
    

-du

  • 顯示目錄中所有文件的大小
    Display the size of files in given folder
    $ hadoop fs -du input
    
    Found 4 items
    115045564   hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/1.txt
    987864      hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/2.txt
    1573048     hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/3.txt
    25844527    hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/4.txt
    

-dus

  • 顯示該目錄/文件的總大小
    Display total size of given folder
    $ hadoop fs -dus input
    
    hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input	143451003
    

-expunge

  • 清空垃圾桶
    Clean up Recycled
    $ hadoop fs -expunge
    

-getmerge

  • 將來源目錄<src>下所有的文件都集合到本地端一個<localdst>檔案內
    Merge all files in HDFS source folder <src> into one local file
    $ hadoop fs -getmerge <src> <localdst> 
    
    $ echo "this is one; " >> in1/input
    $ echo "this is two; " >> in1/input2
    $ hadoop fs -put in1 in1
    $ hadoop fs -getmerge in1 merge.txt
    $ cat ./merge.txt
    

-ls =

  • 列出文件或目錄的資訊
    List files and folders
  • 文件名 <副本數> 文件大小 修改日期 修改時間 權限 用戶ID 組ID
    <file name> <replication> <size> <modified date> <modified time> <permission> <user id> <group id>
  • 目錄名 <dir> 修改日期 修改時間 權限 用戶ID 組ID
    <folder name> <modified date> <modified time> <permission> <user id> <group id>
    $ hadoop fs -ls
    

-lsr

  • ls 命令的遞迴版本
    list files and folders with recursive
    $ hadoop fs -lsr /
    

-mkdir

  • 建立資料夾
    create directories
    $ hadoop fs -mkdir a b c
    

-moveFromLocal

  • 將 local 端的資料夾剪下移動到 hdfs 上
    move local files or folder to HDFS ( it will delete local files or folder. )
    $ hadoop fs -moveFromLocal in1 in2
    

-mv

  • 更改資料的名稱
    Change file name or folder name.
    $ hadoop fs -mv in2 in3
    

-rm

  • 刪除指定的檔案(不可資料夾)
    Remove given files (not folders)
    $ hadoop fs -rm in1/input
    

-rmr

  • 遞迴刪除資料夾(包含在內的所有檔案)
    Remove given files and folders with recursive
    $ hadoop fs -rmr in1
    

-setrep

  • 設定副本係數
    setup replication numbers of given files or folder
    $ hadoop fs -setrep [-R] [-w] <rep> <path/file>
    
    $ hadoop fs -setrep -w 2 -R input 
    Replication 2 set: hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/1.txt
    Replication 2 set: hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/2.txt
    Replication 2 set: hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/3.txt
    Replication 2 set: hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/4.txt
    Waiting for hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/1.txt ... done
    Waiting for hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/2.txt ... done
    Waiting for hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/3.txt ... done
    Waiting for hdfs://hadoop.nchc.org.tw:9000/user/hXXXX/input/4.txt ... done
    

-stat

  • 印出時間資訊
    Print Status of time stamp of folder
    $ hadoop fs -stat input
    2009-04-02 03:51:29
    

-tail

  • 將文件的最後 1K 內容輸出
    Display the last 1K contents of given file
  • 用法 Usage
    hadoop fs -tail [-f] 檔案 (-f 參數用來顯示如果檔案增大,則秀出被append上得內容)
    hadoop fs -tail [-f] <path/file> (-f is used when file had appended)
    
    $ hadoop fs -tail input/1.txt
    

-test

  • 測試檔案, -e 檢查文件是否存在(1=存在, 0=否), -z 檢查文件是否為空(1=空, 0=不為空), -d 檢查是否為目錄(1=存在, 0=否)
    test files or folders
    -e : check if file or folder existed ( 1 = exist , 0 = false )
    -z : check if file is empty ( 1 = empty , 0 = false )
    -d : check if given path is folder ( 1 = it's folder , 0 = false )
    • 要用 echo $? 來看回傳值為 0 or 1
      You have to use echo $? to get the return value
  • 用法 Usage
    $ hadoop fs -test -[ezd] URI
    

$ hadoop fs -test -e /user/hXXXX/input/5.txt
$ hadoop fs -test -z /user/hXXXX/input/5.txt
test: File does not exist: /user/hXXXX/input/5.txt
$ hadoop fs -test -d /user/hXXXX/input/5.txt

test: File does not exist: /user/hXXXX/input/5.txt

-text

  • 將檔案(如壓縮檔, textrecordinputstream)輸出為純文字格式
    Display archive file contents into STDOUT
    $ hadoop fs -text <src>
    
    $ hadoop fs -text macadr-eth1.txt.gz
    00:1b:fc:61:75:b1
    00:1b:fc:58:9c:23
    
  • ps : 目前沒支援zip的函式庫
    PS. It does not support zip files yet.
    $ hadoop fs -text b/a.txt.zip
    PK
    ���:��H{
            a.txtUT	b��Ib��IUx��sssss
    test
    PK
    ���:��H{
    ��a.txtUTb��IUxPK@C
    

-touchz

  • 建立一個空文件
    creat an empty file
    $ hadoop fs -touchz b/kk
    $ hadoop fs -test -z b/kk
    $ echo $?
    1
    $ hadoop fs -test -z b/a.txt.zip
    $ echo $?
    0