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Posted to common-user@hadoop.apache.org by Oleg Ruchovets <or...@gmail.com> on 2010/03/23 11:18:34 UTC

execute mapreduce job on multiple hdfs files

Hi ,
All examples that I found executes mapreduce job on a single file but in my
situation I have more than one.

Suppose I have such folder on HDFS which contains some files:

    /my_hadoop_hdfs/my_folder:
                /my_hadoop_hdfs/my_folder/file1.txt
                /my_hadoop_hdfs/my_folder/file2.txt
                /my_hadoop_hdfs/my_folder/file3.txt


How can I execute  hadoop mapreduce on file1.txt , file2.txt and file3.txt?

Is it possible to provide to hadoop job folder as parameter and all files
will be produced by mapreduce job?

Thanks In Advance
Oleg

Re: execute mapreduce job on multiple hdfs files

Posted by Amogh Vasekar <am...@yahoo-inc.com>.
Hi,
Piggybacking on Gang’s reply, to add files / dirs recursively you can use the filestatus, liststatus to determine if its a file or dir and add as needed ( check FileStatus API for this ) There is a patch which does this for FileInputFormat

http://issues.apache.org/jira/browse/MAPREDUCE-1501


Amogh


On 3/23/10 6:25 PM, "Gang Luo" <lg...@yahoo.com.cn> wrote:

Hi Oleg,
you can use FileInputFormat.addInputPath(JobConf, Path) multiple times in your program to add arbitrary paths. Instead, if you use FileInputFormat.setInputPath, there could be only one input path.

If you are talking about output, the path you give is an output directory, all the output files (part-00000, part-00001...) will be generated in that directory.

-Gang




----- 原始邮件 ----
发件人： Oleg Ruchovets <or...@gmail.com>
收件人： common-user@hadoop.apache.org
发送日期： 2010/3/23 (周二) 6:18:34 上午
主   题： execute mapreduce job on multiple hdfs files

Hi ,
All examples that I found executes mapreduce job on a single file but in my
situation I have more than one.

Suppose I have such folder on HDFS which contains some files:

    /my_hadoop_hdfs/my_folder:
                /my_hadoop_hdfs/my_folder/file1.txt
                /my_hadoop_hdfs/my_folder/file2.txt
                /my_hadoop_hdfs/my_folder/file3.txt


How can I execute  hadoop mapreduce on file1.txt , file2.txt and file3.txt?

Is it possible to provide to hadoop job folder as parameter and all files
will be produced by mapreduce job?

Thanks In Advance
Oleg

Re: execute mapreduce job on multiple hdfs files

Posted by Gang Luo <lg...@yahoo.com.cn>.
Hi Oleg,
you can use FileInputFormat.addInputPath(JobConf, Path) multiple times in your program to add arbitrary paths. Instead, if you use FileInputFormat.setInputPath, there could be only one input path.

If you are talking about output, the path you give is an output directory, all the output files (part-00000, part-00001...) will be generated in that directory.

-Gang
 



----- 原始邮件 ----
发件人： Oleg Ruchovets <or...@gmail.com>
收件人： common-user@hadoop.apache.org
发送日期： 2010/3/23 (周二) 6:18:34 上午
主   题： execute mapreduce job on multiple hdfs files

Hi ,
All examples that I found executes mapreduce job on a single file but in my
situation I have more than one.

Suppose I have such folder on HDFS which contains some files:

    /my_hadoop_hdfs/my_folder:
                /my_hadoop_hdfs/my_folder/file1.txt
                /my_hadoop_hdfs/my_folder/file2.txt
                /my_hadoop_hdfs/my_folder/file3.txt


How can I execute  hadoop mapreduce on file1.txt , file2.txt and file3.txt?

Is it possible to provide to hadoop job folder as parameter and all files
will be produced by mapreduce job?

Thanks In Advance
Oleg