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  • All, What I want to do is output from my reducer multiple files one for each key value. Can this still be done in the current API? It seems that using MultipleTextOutputFormat requires one to use ...
    Geoffry RobertsGeoffry Roberts
    Sep 29, 2009 at 8:45 pm
    Dec 15, 2009 at 4:05 pm
  • I have a Mapper class which needs access to several dependencies (such as a db). It seems that because the framework is new'ing up instances of my Mapper class, I have little control over its ...
    Lowell KirshLowell Kirsh
    Sep 4, 2009 at 8:26 pm
    Sep 15, 2009 at 3:39 pm
  • Hi, I am using Hadoop 0.20. I can pass input values from the driver code into the mapper/reducer code using the Configuration, something like this: // driver code: Job job = new Job(conf, "name"); ...
    Sujit PalSujit Pal
    Sep 24, 2009 at 12:49 am
    Sep 24, 2009 at 3:00 pm
  • Hi, all I am a newbie to hadoop and just begin to play it recent days. I am trying to write a mapreduce program to parse a large dataset (about 20G) to abstract object id and store to HBase table. ...
    Yin_hongbinYin_hongbin
    Sep 29, 2009 at 8:44 am
    Oct 5, 2009 at 7:21 pm
  • Is it true that distributed cache only work for a single job? Is it possible for 2 different jobs to share the same local copy of the same file from distributed cache? Thanks, Zheng
    Zheng ShaoZheng Shao
    Sep 30, 2009 at 5:47 am
    Sep 30, 2009 at 6:11 am
  • I have a hadoop cluster across 2 racks. One rack contains 12 nodes, the other rack contains 5 nodes. When I run a really large job, the disks on the 5 nodes fill up much sooner than the disks on the ...
    Stuart WhiteStuart White
    Sep 29, 2009 at 5:20 pm
    Sep 29, 2009 at 9:51 pm
  • In 0.19.x, the WEB GUI can show the progress of each map or reduce task (before it complete, it is from the RecordReader). But in 0.20.0, we cannot show the progress (always 0%) before map or reduce ...
    Schubert ZhangSchubert Zhang
    Sep 5, 2009 at 6:07 pm
    Sep 5, 2009 at 6:58 pm
  • Hi! Let's assume an example use case where Apache's mod_usertrack generates randomly selected user id's that are stored in a cookie and written to the log file. I want to keep track of the number of ...
    Erik ForsbergErik Forsberg
    Sep 1, 2009 at 9:28 am
    Sep 1, 2009 at 9:44 am
  • This is a friendly reminder that the next Apache Hadoop Get Together takes place next week on Tuesday, 29th of September* at newthinking store (Tucholskystr. 48, Berlin): ...
    Isabel DrostIsabel Drost
    Sep 22, 2009 at 10:12 am
    Sep 22, 2009 at 10:12 am
  • I see that I can use MultipleSequenceFileOutputFormat to output to multiple sequence files. It appears, using this class, that all of the sequence files must have the same key and value class types. ...
    Stuart WhiteStuart White
    Sep 18, 2009 at 4:50 pm
    Sep 18, 2009 at 4:50 pm
  • All, I have an issue wrt common file access from within a map reduce job. I have tried to do this two ways and wind up with either a FileNotFoundException or a EOFException. 1. I copy the file into ...
    Geoffry RobertsGeoffry Roberts
    Sep 15, 2009 at 3:07 pm
    Sep 15, 2009 at 3:07 pm
  • Hi All, Regarding the JVM reuse feature incorporated, it says reuse is generally recommended for streaming and pipes jobs. I'm a little unclear on this and any pointers will be appreciated. Also, in ...
    Amogh VasekarAmogh Vasekar
    Sep 15, 2009 at 7:04 am
    Sep 15, 2009 at 7:04 am
  • Is there a way for my mapper to know in its close() method whether it succeeded, failed, or was killed? (Not sure if this is relevant to the question, but I'm using the "old"/pre-0.20 MapReduce API).
    Stuart WhiteStuart White
    Sep 8, 2009 at 5:14 pm
    Sep 8, 2009 at 5:14 pm
  • Hi, I've started a very basic effort to facilitate MapReduce development using the Common Language Runtime (CLR/.NET/Mono). This would allow writing MapReduce applications using any CLR supported ...
    Fredrik HedbergFredrik Hedberg
    Sep 3, 2009 at 11:47 am
    Sep 3, 2009 at 11:47 am
  • Hi all, The 3rd Hadoop in China event (Hadoop World:Beijing 2009) is open for registration now. http://hadoop-world-beijing.eventbrite.com/ Please register as early as possible. Thanks, Yongqiang
    He YongqiangHe Yongqiang
    Sep 2, 2009 at 1:04 am
    Sep 2, 2009 at 1:04 am
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