Hadoop MapReduce provide nested directories as job input

Question

I'm working on a job that processes a nested directory structure, containing files on multiple levels:

one/
├── three/
│   └── four/
│       ├── baz.txt
│       ├── bleh.txt
│       └── foo.txt
└── two/
    ├── bar.txt
    └── gaa.txt

When I add one/ as an input path, no files are processed, since none are immediately available at the root level.

I read about job.addInputPathRecursively(..), but this seems to have been deprecated in the more recent releases (I'm using hadoop 1.0.2). I've written some code to walk the folders and add each dir with job.addInputPath(dir), which worked until the job crashed when trying to process a directory as an input file for some reason, e.g. - trying to fs.open(split.getPath()), when split.getPath() is a directory (This happens inside LineRecordReader.java).

I'm trying to convince myself there has to be a simpler way to provide a job with a nested directory structure. Any ideas?

EDIT - apparently there's an open bug on this.

Answer 1

Don't know if still relevant but at least in hadoop 2.4.0 you can set property mapreduce.input.fileinputformat.input.dir.recursive to true and it will solve your problem.

Answer 2

I didn't found any document on this but */* works. So it's -input 'path/*/*'.

Answer 3

import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;

FileInputFormat.setInputDirRecursive(job, true);

No thanks, just call me LeiFeng!

Answer 4

I find recursively going through data can be dangerous since there may be lingering log files from a distcp or something similar. Let me propose an alternative:

Do the recursive walk on the command line, and then pass in the paths in a space-delimited parameter into your MapReduce program. Grab the list from argv:

$ hadoop jar blah.jar "`hadoop fs -lsr recursivepath | awk '{print $8}' | grep '/data.*\.txt' | tr '\n' ' '`"

Sorry for the long bash, but it gets the job done. You could wrap the thing in a bash script to break things out into variables.

I personally like the pass-in-filepath approach to writing my mapreduce jobs so the code itself doesn't have hardcoded paths and it's relatively easy for me to set it up to run against more complex list of files.

Answer 5

just use FileInputFormat.addInputPath("with file pattern"); i am writing my first hadoop prog for graph analysis where input is from diff dir in .gz format ... it worked for me !!!