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30 discussions - 82 posts

  • Hi all, this is my first post to this list, and if i'm not in appropriate place, please let me know. I have just created a Hadoop instance and its HDFS is configured as: dfs.replication = 1 ...
    Kiyoshi MizumaruKiyoshi Mizumaru
    May 14, 2010 at 6:38 am
    May 27, 2010 at 11:09 am
  • Hi, According to the job tracker history viewer on our Hadoop setup, all of our recent jobs were run on Wed May 05 15:58:58 UTC 2010. When you click on the individual jobs you get the correct times ...
    James HammertonJames Hammerton
    May 17, 2010 at 9:06 am
    May 18, 2010 at 8:48 am
  • Hi, I tried using the "hadoop fs -text" command to read a sequence file generated by a map reduce job and got the following error: text: java.io.IOException: WritableName can't load class: ...
    James HammertonJames Hammerton
    May 27, 2010 at 6:07 pm
    Jun 4, 2010 at 8:40 am
  • I have a distributed system on NFS, and wanted to use MapReduce on it, but the system keeps spawning errors related to inability to allocate temporary space. Though sufficient is available, hence my ...
    Jyothish SomanJyothish Soman
    May 10, 2010 at 6:01 pm
    Aug 3, 2010 at 7:06 pm
  • Hi all, How can I write tab-delimited output files from my reducer? My reducer gets Text/Text key/vals like: hostX_2010-05-01 varA=valA1,varB=valB1,varC=valC1 hostX_2010-05-01 ...
    Alan MillerAlan Miller
    May 12, 2010 at 9:10 pm
    May 13, 2010 at 9:20 pm
  • Hi, I'm a new user. I have a question about aborting an ongoing mapreduce job. If one of the mappers compute a particular value, I'd like to stop the entire job, and give the control back to the ...
    Ersoy BayramogluErsoy Bayramoglu
    May 3, 2010 at 11:56 pm
    May 4, 2010 at 2:17 pm
  • Hi, Is there a way to search this mailing list? I don't see any search box on the archives page. http://mail-archives.apache.org/mod_mbox/hadoop-mapreduce-user/ thanks, Juber
    Juber patelJuber patel
    May 26, 2010 at 1:22 am
    Jun 5, 2010 at 3:19 am
  • I've been thinking (which is always a dangerous thing) about data locality lately. If we look at file systems, there is this idea of 'reserved space'. This space is used for a variety of reasons, ...
    Allen WittenauerAllen Wittenauer
    May 28, 2010 at 6:38 pm
    May 29, 2010 at 1:10 am
  • Hi, Does anybody know whether or not speculative execution works with Hadoop streaming? If so, I have a script that does not appear to ever launch redundant mappers for the slow performers. This may ...
    Gregory LawrenceGregory Lawrence
    May 27, 2010 at 8:38 pm
    May 28, 2010 at 5:13 pm
  • MessageHi, I'm trying to understand how to generate multiple outputs in my reducer (using 0.20.2+228). Do I need MultipleOutput or should I partition my output in the mapper? My reducer currently ...
    Some BodySome Body
    May 10, 2010 at 12:08 pm
    May 10, 2010 at 5:45 pm
  • Hello, Can Hadoop take advantage of the fact that the output of each map task is almost sorted? On a related note, Does Hadoop's Quicksort implementation give worst case performance on almost sorted ...
    Juber patelJuber patel
    May 29, 2010 at 5:59 am
    Jun 1, 2010 at 3:12 am
  • Hello, Does any body has a working example of DBOutputformat. That connects to the DB Server (MYSQL) and then writes a record to the table. I tried by following the instruction on ...
    Nishant SonarNishant Sonar
    May 19, 2010 at 7:37 am
    May 22, 2010 at 8:03 am
  • Hi, I'm study the MapReduce code, and I've the following questions: 1 - I'm running the wordcount example. I've 3 txt files as input. Each txt file is about 120Mb. During the execution of the map ...
    Psdc1978Psdc1978
    May 18, 2010 at 5:01 pm
    May 18, 2010 at 8:57 pm
  • Hello I have a requirement where i need to run the mapreduce program from another java program. I need some mechanism for submitting the job not from the command line but some other java program ...
    Nishant SonarNishant Sonar
    May 27, 2010 at 7:59 am
    May 27, 2010 at 3:27 pm
  • Hi, I defined in the mapred-site.xml the following property: <configuration <property <name mapred.job.tracker</name <value local</value </property (...) </configuration But when I start map reduce I ...
    Psdc1978Psdc1978
    May 21, 2010 at 8:08 am
    May 22, 2010 at 8:06 am
  • Hi all, Is there a way to access in a map, the name of the input file from which the key, value pair has come from ? Thanks H Morpheus: Do you believe in fate, Neo? Neo: No. Morpheus: Why Not? Neo: ...
    Himanshu chandolaHimanshu chandola
    May 17, 2010 at 4:03 pm
    May 17, 2010 at 4:09 pm
  • Hello, I am a bit confused between MultithreadedMapRunner and MultithreadedMapper classes. Basically I have huge "side data" (4GB) for the map part and I want it in memory. I don't want each mapper ...
    Juber patelJuber patel
    May 17, 2010 at 1:56 am
    May 17, 2010 at 11:51 am
  • Hi all, I'm doing some evaluation using a vanilla 20.2 release on a small cluster to sort large data sets. I've looked at the terasort work, but in my particular case I'm more interested in ...
    Karl KuntzKarl Kuntz
    May 10, 2010 at 3:49 pm
    May 10, 2010 at 4:21 pm
  • Hi all, I've been tinkering with hadoop for some time, but am new to the mailing list. Please forgive me if this has already been asked and answered. I am attempting to use the Distributed Cache to ...
    Mark TozziMark Tozzi
    May 4, 2010 at 10:53 pm
    May 5, 2010 at 4:38 am
  • Hi All, I'm not sure if this is the correct mailing list to ask. Are there job traces available online that I can download? Are there any tutorial/docs on how to use Rumen? Is it possible to use ...
    Harold LimHarold Lim
    May 3, 2010 at 8:46 pm
    May 3, 2010 at 8:51 pm
  • Greetings, I'm attempting to open a RandomAccessFile that is in HDFS for purely reading purposes but I'm getting a FileNotFoundException. I'm attaching a short Java program that tries to do the ...
    Joe BuckJoe Buck
    May 29, 2010 at 6:29 am
    May 29, 2010 at 6:29 am
  • Hi, I'm looking to the method fetchOutputs from the ReduceTask.java, but there's a part of the method that I don't understand. Inside the method, in the synchronized (scheduledCopies) {...}, I don't ...
    Psdc1978Psdc1978
    May 27, 2010 at 8:29 pm
    May 27, 2010 at 8:29 pm
  • Hi there, I've got a simple Map Reduce application that works perfectly when I use NFS as an underlying filesystem (not using HDFS at all). I've got a working HDFS configuration as well - grep ...
    Marcin SieniekMarcin Sieniek
    May 26, 2010 at 4:40 pm
    May 26, 2010 at 4:40 pm
  • Hello, I am using Hadoop 0.20.2 with the new mapreduce API. I have a class that will be used as a value to mapper/reducer. I have implemented Writable as follows, but I am not sure this is the right ...
    Juber patelJuber patel
    May 26, 2010 at 7:17 am
    May 26, 2010 at 7:17 am
  • Hi all, I just try to use MultithreadedMapRunner for wordcount with 2 threads in one maptask, but each maptask gets the following exception, and the job failed eventually. But when running with only ...
    Guo LeitaoGuo Leitao
    May 24, 2010 at 8:43 am
    May 24, 2010 at 8:43 am
  • Hello all, I am trying to install HBase and while going through the requirements (link below), it asked me to apply HDFS-630 patch. The latest 2 patches are for Hadoop 0.21. I am using version 0.20. ...
    Raghava MutharajuRaghava Mutharaju
    May 14, 2010 at 2:59 am
    May 14, 2010 at 2:59 am
  • Hello Fellow Hadoopists, We are meeting the 3rd Thursday of the month and covering predominately only Hadoop and the infrastructure surrounding it. This *not* the same meeting as listed on ...
    Sean Jensen-GreySean Jensen-Grey
    May 11, 2010 at 9:49 pm
    May 11, 2010 at 9:49 pm
  • Hi all, According to this mail <http://mail-archives.apache.org/mod_mbox/hadoop-general/201004.mbox/%3C121803A3-CFB9-489B-96EF-027234E55D25@apache.org%3E , Google has granted a license for Hadoop, ...
    Andy ZhuAndy Zhu
    May 5, 2010 at 2:14 am
    May 5, 2010 at 2:14 am
  • Hadoop is working fine in Linux. In Windows (using cygwin) I can't get mapred to work, though hdfs is ok. This is the stacktrace: java.io.FileNotFoundException: File ...
    Carlos Eduardo Moreira dos SantosCarlos Eduardo Moreira dos Santos
    May 2, 2010 at 4:45 am
    May 2, 2010 at 4:45 am
  • Hi, I'm trying to start the IsolationRunner class with the example of the wordcount. But to try to do that I'm using the temp data that was created during a normal execution of the wordcount example. ...
    Psdc1978Psdc1978
    May 1, 2010 at 7:18 pm
    May 1, 2010 at 7:18 pm
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41 users for May 2010

Psdc1978: 7 posts Alex Kozlov: 5 posts James Hammerton: 5 posts Kiyoshi Mizumaru: 5 posts Some Body: 5 posts Juber patel: 4 posts Aaron Kimball: 3 posts Amareshwari Sri Ramadasu: 3 posts Ted Yu: 3 posts Allen Wittenauer: 2 posts Deepika Khera: 2 posts Ersoy Bayramoglu: 2 posts Gregory Lawrence: 2 posts Harold Lim: 2 posts Hemanth Yamijala: 2 posts Koji Noguchi: 2 posts Marcin Sieniek: 2 posts Nishant Sonar: 2 posts Sonal Goyal: 2 posts Alex kamil: 1 post
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