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17 discussions - 45 posts

  • Hi, I use cloudera's distribution for hadoop. What I see is that a small fraction of maps get stuck at 100%. They show up as 100% but continue running. After a lot of delay, they succeed finally but ...
    Himanshu chandolaHimanshu chandola
    Nov 24, 2009 at 7:48 am
    Nov 24, 2009 at 9:37 am
  • hi, I'm try to write a hadoop streaming job by perl. But i'm complately confused by the key/value separator. I found lots of separators I can set ... # -jobconf stream.map.output.field.separator=A \ ...
    WdWd
    Nov 10, 2009 at 3:55 am
    Nov 17, 2009 at 9:02 am
  • Hey all, I am trying to figure out the best way to approach some joining/merging computation in a map-reduce / hbase framework. I have the following large timeseries datasets (key/value pairs keyed ...
    CalvinCalvin
    Nov 4, 2009 at 4:54 pm
    Nov 5, 2009 at 5:52 pm
  • I wrote a simple code in my eclipse as Text t = new Text("hadoop"); System.out.println((char)t.charAt(2)); when I try to run this I got Exception in thread "main" java.lang.NoClassDefFoundError: ...
    Felix gaoFelix gao
    Nov 14, 2009 at 7:52 pm
    Nov 17, 2009 at 6:18 pm
  • Hi, briefly, I'm writing my dissertation on Distributed computation, and then in detail at the various interfaces atop of Hadoop, including Pig, Hive, JAQL etc... One thing I have noticed in early ...
    Rob StewartRob Stewart
    Nov 7, 2009 at 7:02 pm
    Nov 12, 2009 at 2:04 am
  • hi all, We are using hadoop-0.19.1 on about 200 nodes. We find there are lots of slaves keep Child process even the job is done. Here is an example, the process is running since "AUGEST 09"! jstack ...
    Ted XuTed Xu
    Nov 12, 2009 at 7:07 am
    Nov 18, 2009 at 1:54 am
  • I want to know if I can "wire" mapper and reducer classes. By "wire" I mean to use inversion of control (or dependency injection). For example, I see in a lot of books and on the Map/Reduce tutorial ...
    Java DeveloperJava Developer
    Nov 12, 2009 at 6:29 am
    Nov 12, 2009 at 8:17 am
  • Dear hadoop fellows, We have been using Hadoop-0.20.1 MapReduce to crawl some web data. In this case, we only have mappers to crawl data and save data into HDFS in a distributed way. No reducers is ...
    Zhang Bingjun (Eddy)Zhang Bingjun (Eddy)
    Nov 2, 2009 at 8:33 am
    Nov 2, 2009 at 10:41 am
  • Hi all, 1 - I'm trying to compile hadoop-0.20.1 but I'm facing several errors. Hadoop includes several subprojects, but these subprojects are all compiled in one file called hadoop-0.20.1-core.jar. ...
    Psdc1978Psdc1978
    Nov 24, 2009 at 10:17 am
    Nov 24, 2009 at 10:23 am
  • Hi All! How much overhead using Hadoop Streming vs. native Java steps does add? How can I estimate performance increase I can get by rewriting my streaming job to Java? What parameters the overhead ...
    Alexey TigarevAlexey Tigarev
    Nov 12, 2009 at 10:07 pm
    Nov 17, 2009 at 6:28 am
  • Hey all, I am currenty trying to write a simple map job that dumps a file to the hdfs. I see that hadoop creates 3 instances of my mapper class (I expected 3, so this is fine :) but then things get a ...
    Max HeimelMax Heimel
    Nov 14, 2009 at 12:04 pm
    Nov 17, 2009 at 6:27 am
  • Hi all, I have 2 KVP files of 200million+ rows, and plan to do a reduce side join (my first...). Input 1 ---------- KEY TC_ID Input 2 ---------- KEY OCC_ID I aim to produce an output of: Output ...
    Tim RobertsonTim Robertson
    Nov 12, 2009 at 3:14 pm
    Nov 12, 2009 at 3:20 pm
  • (moving to mapreduce-user@hadoop.apache.org) Use one of the several ways to pass the queue name as a config variable: JobConf j = new JobConf(); j.setQueueName("myqueue"); or cmd line: hadoop jar ...
    Arun C MurthyArun C Murthy
    Nov 25, 2009 at 12:11 am
    Nov 25, 2009 at 12:11 am
  • hello I am using hadoop wordcount examples and trying to use jobcleint API to get the status of map and reduce as i am trying to get my own status bar for the map reduce instead using JobTracker.jsp ...
    Rajan DevRajan Dev
    Nov 11, 2009 at 12:47 pm
    Nov 11, 2009 at 12:47 pm
  • Hello, I need to know how to configure a job implemented in java (in Hadoop Training Cloudera VM) to run only one Reduce Task and it begins only when all Map Tasks have completed their execution. I ...
    Ajhtal KuchipudiAjhtal Kuchipudi
    Nov 10, 2009 at 2:24 pm
    Nov 10, 2009 at 2:24 pm
  • Dear Hadoop fellows, We have been using Hadoop-0.18.3 to run MapReduce in web application. We have tried to run the application in both Jetty 6.1 and Tomcat 6.0. At first, we directly call the ...
    Johnny.rebornJohnny.reborn
    Nov 4, 2009 at 1:07 pm
    Nov 4, 2009 at 1:07 pm
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groupmapreduce-user @
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25 users for November 2009

Jason Venner: 6 posts Arun C Murthy: 3 posts Dmitriy Ryaboy: 3 posts Himanshu chandola: 3 posts Wd: 3 posts Aaron Kimball: 2 posts Felix gao: 2 posts Rekha Joshi: 2 posts Rob Stewart: 2 posts Ted Xu: 2 posts Tim Robertson: 2 posts Zhang Bingjun (Eddy): 2 posts Ajhtal Kuchipudi: 1 post Alexey Tigarev: 1 post Amogh Vasekar: 1 post Calvin: 1 post Java Developer: 1 post Johnny.reborn: 1 post Max Heimel: 1 post Palleti, Pallavi: 1 post
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