Yes, I know that, but this answer won't answer my questions. On Mon, Apr 5, 2010 at 12:31 PM, Rekha Joshi <[email protected]> wrote:
> In manner of providing a quick byte, /tmp folder( check hadoop.tmp.dir) > is only temporarily used by MR process and they are ideally cleaned up after > the job has finished execution on cleanup/abort. > MR is a process which loads/stores data in HDFS. Most of your queries > relate to knowing your default hdfs location. You can find that by “hadoop > dfs –ls”.The path preceding .Trash is your default hdfs location. > > HTH, > / > > On 4/5/10 4:24 PM, "psdc1978" <[email protected]> wrote: > > Hi, > > When I run an MapReduce example, I've noticed that some temporary > directories are buit in /tmp directory. > > In my case, in the /tmp/hadoop directory it was created the following file > directory during the execution of wordcount example: > > > job_201004041803_0002/ > |-- attempt_201004041803_0002_m_000000_0_0_m_0 > | |-- job.xml > | |-- output > | | |-- file.out > | | `-- file.out.index > | |-- pid > | `-- split.dta > > 1 - In the map attempt task it exists a file.out and split.dta file.The > split.dta is the map output produced by the map and that will be fetched by > the reducer? > > 2 - What's the file.out and file.out.index? > > 3 - Is this data were written by MR anything related to HDFS? > > 4 - I'm a bit confused to differentiate between the files that are written > in /tmp directory during the execution of my example, and the place where > the files are written with the command > "bin/hadoop dfs -copyFromLocal". > > a) When I execute the "bin/hadoop dfs -copyFromLocal <from> <to>" command, > where's the destination folder? > > b) Is it in memory or is physically in my HD? > > c) If the files are written in the HD, in wich directory are they? > > d) What is the difference between the data written win the command > -copyFromLocal and the data written in the /tmp directory? > > > 5 - The output of a reducer example comes in the form part_0000 that is > written in gutenberg-output. Where is this file? Is it in my HD? > > > Thank you, > > -- Pedro
