作者：二青
邮箱：xtfggef@gmail.com 微博：http://weibo.com/xtfggef
这篇文章主要是讲一下位于bin下的hadoop命令，我们可以直接输入hadoop无任何参数看一下：
用法就是：hadoop [---config confdir] COMMAND此处COMMAND就是下面列出来的那些，fs, version,jar 等等。
用户命令
fs
目前版本的hadoop已经摒弃了fs命令，取而代之的是hdfs dfs.
Usage: hdfs dfs [GENERIC_OPTIONS] [COMMAND_OPTIONS], 熟悉linux命令的同学学这个很快，举个例子，创建目录，mkdir，在这里为：hdfs dfs -mkdir /test
解释：此处-mkdir即为GENERIC_OPTIONS，后面的/test为COMMAND_OPTIONS，默认路径为/，所以执行完上面的操作后，我们在根路径/下面创建了test目录。下面是我总结了一下hadoop中fs相关的命令，亦可见文件EXCEL。
| 参数 | 作用 | 示例 | 返回值 |
| appendToFile | 将一个或者多个本地 文件追加到目的文件 |
hdfs dfs -appendToFile localfile /user/hadoop/hadoopfile | Returns 0 on success and 1 on error |
| cat | 输出文件 | hdfs dfs -cat file:///file3 /user/hadoop/file4 | Returns 0 on success and -1 on error |
| chgrp | 改变文件的分组 | hdfs dfs -chgrp [-R] GROUP URI [URI ...] | |
| chmod | 改变文件的权限 | hdfs dfs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI [URI ...] | |
| chown | 改变文件的拥有者 | hdfs dfs -chown [-R] [OWNER][:[GROUP]] URI [URI ] | |
| copyFromLocal | 从本地复制 | ||
| copyToLocal | 复制到本地 | ||
| count | 得到文件/目录等数目 追加参数-q, -h有不同的意义 |
hdfs dfs -count -q hdfs://nn1.example.com/file1 | Returns 0 on success and -1 on error |
| cp | 复制，参数-f,-p | hdfs dfs -cp /user/hadoop/file1 /user/hadoop/file2 | Returns 0 on success and -1 on error |
| du | 得到指定文件的大小 | hdfs dfs -du /test/hadoop | Returns 0 on success and -1 on error. |
| dus | 已摒弃，和du类似 | ||
| expunge | 清空回收站 | hdfs dfs -expunge | |
| get | 复制文件到本地路径下 | hdfs dfs -get /user/hadoop/file localfile | Returns 0 on success and -1 on error |
| getfacl | 显示文件或者目录的权限控制列表 | hdfs dfs -getfacl /file hdfs dfs -getfacl -R /dir |
Returns 0 on success and non-zero on error |
| getfattr | 显示文件或者目录的扩展属性 | hdfs dfs -getfattr -d /file | Returns 0 on success and non-zero on error |
| getmerge | 合并多个文件一个目标文件里 | hdfs dfs -getmerge <src> <localdst> [addnl] | |
| ls | 和linux里一样 | hdfs dfs -ls /user/hadoop/file1 | Returns 0 on success and -1 on error |
| lsr | 等同于ls -R | ||
| mkdir | 创建目录，-p创建多层目录 | hdfs dfs -mkdir /user/hadoop/dir1 /user/hadoop/dir2 | Returns 0 on success and -1 on error |
| moveFromLocal | 类似put，区别在于put完后删除 原文件 |
||
| moveToLocal | 目前没有实现 | ||
| mv | 移动文件 | hdfs dfs -mv /user/hadoop/file1 /user/hadoop/file2 | Returns 0 on success and -1 on error |
| put | 像目标目录推送文件 | hdfs dfs -put localfile /user/hadoop/hadoopfile | Returns 0 on success and -1 on error |
| rm | 删除文件 | hdfs dfs -rm hdfs://nn.example.com/file /user/hadoop/emptydir | Returns 0 on success and -1 on error |
| rmr | 类似于rm -r | ||
| setfacl | 设置文件或者目录的权限控制列表 | hdfs dfs -setfacl -m user:hadoop:rw- /file | Returns 0 on success and non-zero on error |
| setfattr | 设置文件或者目录的扩展属性 | hdfs dfs -setfattr -n user.myAttr -v myValue /file | Returns 0 on success and non-zero on error |
| setrep | 改变文件和目录的复制因子 | hdfs dfs -setrep -w 3 /user/hadoop/dir1 | Returns 0 on success and -1 on error |
| stat | 返回路径信息 | hdfs dfs -stat path | Exit Code: Returns 0 on success and -1 on error |
| tail | 输出文件的最后1千字节 | hdfs dfs -tail pathname | Returns 0 on success and -1 on error |
| test | 检查文件 | hdfs dfs -test -e filename | |
| text | 以文本方式输出文件 | hdfs dfs -text <src> | |
| touchz | 创建空文件 | hdfs dfs -touchz pathname | Returns 0 on success and -1 on error |
version
hadoop version查看hadoop版本信息
jar
可以运行jar文件
credential
这个命令用来管理证书，密钥和一些其他的私有信息。
archive
1. 创建archive
Hadoop archive 是一种特定的文档格式，每一个archive会与相应的系统目录相对应，以*.har结尾。每一个archive文档包含一些信息（metadata）， 记录该文档的一些信息，如索引，数据等。使用如下命令去创建hadoop archive：hadoop archive -archiveName zoo.har -p /foo/bar -r 3 /outputdir
-archiveName：定义要创建的archive文档的名字。
-p: 定义要archive的目录，可以是绝对路径，也可是相对路径。
-r: 定义复制因子，默认是10。
最后一个是输出目录，我们来看一个例子：把/hadoop下的config文件夹打包成config.har并放到/archives下，执行如下命令：
hadoop archive -archiveName config.har -p /hadoop/hadoop/etc -r 1 hadoop /archives
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- root@master:~/hadoop/bin# ./hadoop archive -archiveName config.har -p /hadoop -r 1 config /archives
- 15/01/15 14:28:02 INFO client.RMProxy: Connecting to ResourceManager at master/192.168.1.118:8032
- 15/01/15 14:28:04 INFO client.RMProxy: Connecting to ResourceManager at master/192.168.1.118:8032
- 15/01/15 14:28:04 INFO client.RMProxy: Connecting to ResourceManager at master/192.168.1.118:8032
- 15/01/15 14:28:05 INFO mapreduce.JobSubmitter: number of splits:1
- 15/01/15 14:28:05 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1421303038566_0001
- 15/01/15 14:28:06 INFO impl.YarnClientImpl: Submitted application application_1421303038566_0001
- 15/01/15 14:28:06 INFO mapreduce.Job: The url to track the job: http://master:8088/proxy/application_1421303038566_0001/
- 15/01/15 14:28:06 INFO mapreduce.Job: Running job: job_1421303038566_0001
- 15/01/15 14:28:21 INFO mapreduce.Job: Job job_1421303038566_0001 running in uber mode : false
- 15/01/15 14:28:21 INFO mapreduce.Job: map 0% reduce 0%
- 15/01/15 14:28:33 INFO mapreduce.Job: map 100% reduce 0%
- 15/01/15 14:28:44 INFO mapreduce.Job: map 100% reduce 100%
- 15/01/15 14:28:44 INFO mapreduce.Job: Job job_1421303038566_0001 completed successfully
- 15/01/15 14:28:44 INFO mapreduce.Job: Counters: 49
- File System Counters
- FILE: Number of bytes read=701
- FILE: Number of bytes written=215089
- FILE: Number of read operations=0
- FILE: Number of large read operations=0
- FILE: Number of write operations=0
- HDFS: Number of bytes read=23417
- HDFS: Number of bytes written=23343
- HDFS: Number of read operations=24
- HDFS: Number of large read operations=0
- HDFS: Number of write operations=7
- Job Counters
- Launched map tasks=1
- Launched reduce tasks=1
- Other local map tasks=1
- Total time spent by all maps in occupied slots (ms)=9767
- Total time spent by all reduces in occupied slots (ms)=7888
- Total time spent by all map tasks (ms)=9767
- Total time spent by all reduce tasks (ms)=7888
- Total vcore-seconds taken by all map tasks=9767
- Total vcore-seconds taken by all reduce tasks=7888
- Total megabyte-seconds taken by all map tasks=10001408
- Total megabyte-seconds taken by all reduce tasks=8077312
- Map-Reduce Framework
- Map input records=7
- Map output records=7
- Map output bytes=680
- Map output materialized bytes=701
- Input split bytes=116
- Combine input records=0
- Combine output records=0
- Reduce input groups=7
- Reduce shuffle bytes=701
- Reduce input records=7
- Reduce output records=0
- Spilled Records=14
- Shuffled Maps =1
- Failed Shuffles=0
- Merged Map outputs=1
- GC time elapsed (ms)=291
- CPU time spent (ms)=2090
- Physical memory (bytes) snapshot=306540544
- Virtual memory (bytes) snapshot=1320914944
- Total committed heap usage (bytes)=127242240
- Shuffle Errors
- BAD_ID=0
- CONNECTION=0
- IO_ERROR=0
- WRONG_LENGTH=0
- WRONG_MAP=0
- WRONG_REDUCE=0
- File Input Format Counters
- Bytes Read=632
- File Output Format Counters
- Bytes Written=0
- root@master:~/hadoop/bin#
浏览目录结构，我们看到了生成的har包：
用命令查看，并且copy到本地，得到如下：
我们发现har包看上去就是一个文件夹，不过比较特殊的是，它里面包含metadata，记录文件的基本信息和数据，而且有专门的特殊用途。
2. 查找archive
我们可以像操作普通文件系统一下去操作archive，唯一不同的是查找路径URI，这个需要注意一下。
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- har://scheme-hostname:port/archivepath/fileinarchive
- har:///archivepath/fileinarchive
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- root@master:~/hadoop/bin# ./hdfs dfs -ls har:///archives/config.har
- Found 1 items
- drwxr-xr-x - root supergroup 0 2015-01-15 14:26 har:///archives/config.har/config
3. 解压缩archive
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- hdfs dfs -cp har:///user/zoo/foo.har/dir1 hdfs:/user/zoo/newdir
- hadoop distcp har:///user/zoo/foo.har/dir1 hdfs:/user/zoo/newdir
官方文档
distcp
distcp是一个文件和目录复制命令，用于集群之间已经集群内节点之间的文件复制，详情见官方文档。
fsck
fsck是一个文件系统检查工具，用来检查各类问题，比如文件块丢失等。
用 法：hdfs fsck [GENERIC_OPTIONS] <path> [-list-corruptfileblocks | [-move | -delete | -openforwrite] [-files [-blocks [-locations | -racks]]]] [-includeSnapshots]
| COMMAND_OPTION | Description |
|---|---|
| path | Start checking from this path. |
| -move | Move corrupted files to /lost+found |
| -delete | Delete corrupted files. |
| -files | Print out files being checked. |
| -openforwrite | Print out files opened for write. |
| -includeSnapshots | Include snapshot data if the given path indicates a snapshottable directory or there are snapshottable directories under it. |
| -list-corruptfileblocks | Print out list of missing blocks and files they belong to. |
| -blocks | Print out block report. |
| -locations | Print out locations for every block. |
| -racks | Print out network topology for data-node locations. |
这是一个独立的命令，不属于dfs. 看个例子：检查/下面的文件目录情况。
fetchdt
从namenode上拿到授权符，暂时没有用到，后面更新。
job
与map reduce的job进行交互。
Usage: mapred job | [GENERIC_OPTIONS] | [-submit <job-file>] | [-status <job-id>] | [-counter <job-id> <group-name> <counter-name>] | [-kill <job-id>] | [-events <job-id> <from-event-#> <#-of-events>] | [-history [all] <jobOutputDir>] | [-list [all]] | [-kill-task <task-id>] | [-fail-task <task-id>] | [-set-priority <job-id> <priority>]
| COMMAND_OPTION | Description |
|---|---|
| -submit job-file | Submits the job. |
| -status job-id | Prints the map and reduce completion percentage and all job counters. |
| -counter job-id group-name counter-name | Prints the counter value. |
| -kill job-id | Kills the job. |
| -events job-id from-event-# #-of-events | Prints the events' details received by jobtracker for the given range. |
| -history [all]jobOutputDir | Prints job details, failed and killed tip details. More details about the job such as successful tasks and task attempts made for each task can be viewed by specifying the [all] option. |
| -list [all] | Displays jobs which are yet to complete. -list all displays all jobs. |
| -kill-task task-id | Kills the task. Killed tasks are NOT counted against failed attempts. |
| -fail-task task-id | Fails the task. Failed tasks are counted against failed attempts. |
| -set-priority job-id priority | Changes the priority of the job. Allowed priority values are VERY_HIGH, HIGH, NORMAL, LOW, VERY_LOW |
我们可以通过：mapred job -status <job_id> 来查看job的运行状态。
pipes
运行管道job，稍后更新。
queue
获得与job交互的队列的信息，用法：./mapred queue -info default
CLASSNAME
hadoop可以运行任何java class。
classpath
打印类路径。
管理命令
balancer
查看系统平衡情况，hdfs balancer [-threshold <threshold>] [-policy <policy>], 最直接的用法：./hdfs balancer
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- root@master:~/hadoop/bin# ./hdfs balancer
- 15/01/15 16:20:03 INFO balancer.Balancer: namenodes = [hdfs://master:9000]
- 15/01/15 16:20:03 INFO balancer.Balancer: parameters = Balancer.Parameters[BalancingPolicy.Node, threshold=10.0, number of nodes to be excluded = 0, number of nodes to be included = 0]
- Time Stamp Iteration# Bytes Already Moved Bytes Left To Move Bytes Being Moved
- 15/01/15 16:20:06 INFO net.NetworkTopology: Adding a new node: /default-rack/192.168.1.116:50010
- 15/01/15 16:20:06 INFO net.NetworkTopology: Adding a new node: /default-rack/192.168.1.189:50010
- 15/01/15 16:20:06 INFO balancer.Balancer: 0 over-utilized: []
- 15/01/15 16:20:06 INFO balancer.Balancer: 0 underutilized: []
- The cluster is balanced. Exiting...
- Jan 15, 2015 4:20:06 PM 0 0 B 0 B -1 B
- Jan 15, 2015 4:20:06 PM Balancing took 3.215 seconds
- root@master:~/hadoop/bin#
datanode
运行一个data node，Usage: hdfs datanode [-regular | -rollback | -rollingupgrace rollback]
| COMMAND_OPTION | Description |
|---|---|
| -regular | Normal datanode startup (default). |
| -rollback | Rollback the datanode to the previous version. This should be used after stopping the datanode and distributing the old hadoop version. |
| -rollingupgrade rollback | Rollback a rolling upgrade operation. |
daemonlog
dfsadmin
dfs管理工具，功能比较强大，参考官方文档。
Mover
一个新的数据移植工具，和balancer类似，定期扫描HDFS系统里的archive文件，来检查是否满足HDFS存储策略，如果不满足则将其副本移到另一个地方。
namenode
运行namenode，也是一个比较核心、强大的工具，参考官方文档。
secondarynamenode
运行HDFS次要name node。
hsadmin
管理HDFS history server
historyserver
启动history server，用法：./mapred historyserver
原文链接：http://blog.csdn.net/zhangerqing/article/details/42718103
