hadoop系统 hdfs 命令行操作

Hadoop文件系统shell命令列表: https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/FileSystemShell.html

命令查看:  hadoop fs

[hadoop@mini1 mapreduce]$ hadoop fs
Usage: hadoop fs [generic options]
	[-appendToFile  ... ]
	[-cat [-ignoreCrc]  ...]
	[-checksum  ...]
	[-chgrp [-R] GROUP PATH...]
	[-chmod [-R]  PATH...]
	[-chown [-R] [OWNER][:[GROUP]] PATH...]
	[-copyFromLocal [-f] [-p] [-l] [-d]  ... ]
	[-copyToLocal [-f] [-p] [-ignoreCrc] [-crc]  ... ]
	[-count [-q] [-h] [-v] [-t []] [-u] [-x]  ...]
	[-cp [-f] [-p | -p[topax]] [-d]  ... ]
	[-createSnapshot  []]
	[-deleteSnapshot  ]
	[-df [-h] [ ...]]
	[-du [-s] [-h] [-x]  ...]
	[-expunge]
	[-find  ...  ...]
	[-get [-f] [-p] [-ignoreCrc] [-crc]  ... ]
	[-getfacl [-R] ]
	[-getfattr [-R] {-n name | -d} [-e en] ]
	[-getmerge [-nl] [-skip-empty-file]  ]
	[-help [cmd ...]]
	[-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [ ...]]
	[-mkdir [-p]  ...]
	[-moveFromLocal  ... ]
	[-moveToLocal  ]

1. hdfs文件上传

# 上传 XXX.zip 文件到 / 目录
hadoop fs -put XXX.zip /

2. 查看文件目录列表

[hadoop@mini1 ~]$ hadoop fs -ls /
Found 2 items
-rw-r--r--   2 hadoop supergroup  354635831 2018-04-02 10:27 /jdk-9.0.4_linux-x64_bin.tar.gz
-rw-r--r--   2 hadoop supergroup        279 2018-04-02 10:30 /test.txt

3. 获取文件 hadoop fs -get /XXX

[hadoop@mini2 ~]$ hadoop fs -get /jdk-9.0.4_linux-x64_bin.tar.gz
[hadoop@mini2 ~]$ ls
hadoop-2.9.0  hdfsdata  jdk-9.0.4_linux-x64_bin.tar.gz
[hadoop@mini2 ~]$ 

4. 创建目录 hadoop fs -mkdir /XXX

[hadoop@mini1 ~]$ hadoop fs -mkdir /wordCount
[hadoop@mini1 ~]$ hadoop fs -ls /
Found 3 items
-rw-r--r--   2 hadoop supergroup  354635831 2018-04-02 10:27 /jdk-9.0.4_linux-x64_bin.tar.gz
-rw-r--r--   2 hadoop supergroup        279 2018-04-02 10:30 /test.txt
drwxr-xr-x   - hadoop supergroup          0 2018-04-02 10:44 /wordCount
[hadoop@mini1 ~]$ 

5. 指定jar命令  hadoop jar XXX.jar YYY /wordCount/ /wordCount/output

[hadoop@mini1 mapreduce]$ hadoop jar hadoop-mapreduce-examples-2.9.0.jar wordcount /wordCount/ /wordCount/output
18/04/02 10:48:26 INFO client.RMProxy: Connecting to ResourceManager at mini1/192.168.241.100:8032
18/04/02 10:48:27 INFO input.FileInputFormat: Total input files to process : 2
18/04/02 10:48:28 INFO mapreduce.JobSubmitter: number of splits:2
18/04/02 10:48:28 INFO Configuration.deprecation: yarn.resourcemanager.system-metrics-publisher.enabled is deprecated. Instead, use yarn.system-metrics-publisher.enabled
18/04/02 10:48:28 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1522678018314_0001
18/04/02 10:48:29 INFO impl.YarnClientImpl: Submitted application application_1522678018314_0001
18/04/02 10:48:29 INFO mapreduce.Job: The url to track the job: http://mini1:8088/proxy/application_1522678018314_0001/
18/04/02 10:48:29 INFO mapreduce.Job: Running job: job_1522678018314_0001
18/04/02 10:48:36 INFO mapreduce.Job: Job job_1522678018314_0001 running in uber mode : false
18/04/02 10:48:36 INFO mapreduce.Job:  map 0% reduce 0%
18/04/02 10:48:48 INFO mapreduce.Job:  map 100% reduce 0%
18/04/02 10:48:53 INFO mapreduce.Job:  map 100% reduce 100%
18/04/02 10:48:54 INFO mapreduce.Job: Job job_1522678018314_0001 completed successfully


[hadoop@mini1 mapreduce]$ hadoop fs -cat /wordCount/output/part-r-00000
Apr	2
Don't	1
Jan	1
Mar	1
a	1
and	1
for	2
hadoop	9

[hadoop@mini1 mapreduce]$ 

6. 设置文件副本数 setrep

hadoop fs -setrep 10 XXX.yyy

这里设置的文件副本数是指记录在namenode中的元数据，具体的副本数量还需要看集群中国是否有足够数量的机器存放，如果有则真实的副本数量为元数据中的数量，否则只能达到机器允许的最大数量。