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27 discussions - 102 posts

  • Hi, We are trying to parallelize the ant colony optimization algorithm for TSP over hadoop and are facing some issues. We are using TSPLIB as input files. The input is a text file containing ...
    Sharat attupurathSharat attupurath
    May 4, 2012 at 4:06 pm
    May 8, 2012 at 4:25 pm
  • Hello, I'm trying to tune terasort on a small cluster (4 identical slave nodes w/ 4 disks and 16GB RAM each), but I'm having problems with very uneven load. For teragen, I specify 24 mappers, but for ...
    Trevor RobinsonTrevor Robinson
    May 29, 2012 at 9:34 pm
    Jun 29, 2012 at 10:49 pm
  • Hi, Could anyone suggest how to get the filename in the mapper. I have gone through the JIRA ticket that map.input.file doesnt work in case of multiple inputs,TaggedInputSplit also doesnt work in ...
    Kasi SubrahmanyamKasi Subrahmanyam
    May 3, 2012 at 12:56 pm
    May 6, 2012 at 6:30 am
  • Friends, When Tasktracker exits, then data persist on linux filesystem. (I am using Hadoop without HDFS) but when I restart the tasktracker on that node it cleans all data on it's directory. Is this ...
    Hadoop anisHadoop anis
    May 24, 2012 at 2:34 pm
    May 29, 2012 at 10:47 am
  • Hi, I have an implementation SampleFileOutputCommiter which extends org.apache.hadoop.mapred.FileOutputCommitter . The implementation has specific code to be executed during cleanupJob() execution ...
    SubrotoSubroto
    May 23, 2012 at 9:24 am
    May 23, 2012 at 11:44 am
  • Hi, I am building a MapReduce application that constructs the adjacency list of a graph from an input edge list. I noticed that my Reduce phase always hangs (and timeout eventually) as it calls the ...
    Zuhair KhayyatZuhair Khayyat
    May 5, 2012 at 2:06 pm
    May 5, 2012 at 5:55 pm
  • I have already preordered the third edition of Tom's book (obviously, I don't have it yet since it won't be published until the end of the month), but aside from that, I'm looking for good resources ...
    Keith WileyKeith Wiley
    May 23, 2012 at 10:19 pm
    May 24, 2012 at 6:21 am
  • Hi, All~ Currently, I'm trying to rewrite an algorithm to MapReduce form. Since the algorithm depends on some third-party DLLs which are written in C++, I was wondering would I call a DLL in the ...
    jason Yangjason Yang
    May 23, 2012 at 9:38 am
    May 23, 2012 at 9:44 pm
  • Hi, Though this question may relate to Hadoop-Common project but, I faced the concern while working with MR. The current version of Hadoop deprecates many keys but, takes care of adding the new keys ...
    SubrotoSubroto
    May 22, 2012 at 7:53 am
    May 23, 2012 at 7:45 am
  • Hi, The constructor of Reader class ignores the FileSystem parameter provided in the constructor parameter. This results in creation of Path on the basis of default FileSystem mentioned in the ...
    SubrotoSubroto
    May 18, 2012 at 2:13 pm
    May 18, 2012 at 2:34 pm
  • Would someone please give me some troubleshooting tips for TestDFSIO hanging on a new 0.23.1-cdh4b2 cluster? I've tried both a 5-machine cluster and just running everything on a single node. It's my ...
    Trevor RobinsonTrevor Robinson
    May 14, 2012 at 8:46 pm
    May 14, 2012 at 11:54 pm
  • Hello, This is really a MapReduce question, but the output from this will be used to create regions for an HBase table. Here's what I want to do: Take an input file that contains data about users ...
    Something SomethingSomething Something
    May 12, 2012 at 11:22 pm
    May 13, 2012 at 5:04 pm
  • Hi All, I am running jobs on cluster in my application. In one of my jobs i am getting SocketTimeOutException and job is failing. I have ran the job out of hadoop and it runs fine. But even on pseudo ...
    Ashish vyasAshish vyas
    May 7, 2012 at 4:11 pm
    May 8, 2012 at 7:19 pm
  • Hi, I have a cluster running YARN, and mapreduce jobs run as expected when they are executed from one of the nodes. However, when I run Pig scripts from a remote client, Pig connects to HDFS and ...
    KevinKevin
    May 2, 2012 at 6:41 pm
    May 3, 2012 at 2:36 pm
  • Hi all, I'm not able to find the appropriate regular expression in pig for web log analysis.With logloader it gives result only with available reference values.If reference does not have any value in ...
    Avnish pundirAvnish pundir
    May 27, 2012 at 5:42 am
    May 27, 2012 at 8:45 am
  • Hi, I have a doubt about HDFS which may be a very trivial thing but I am not able to understand it. Since hdfs keeps the files in block of 64/128 MB how does HDFS splits files? The problem which I ...
    Utkarsh GuptaUtkarsh Gupta
    May 18, 2012 at 9:11 am
    May 18, 2012 at 10:23 am
  • Hi, I am trying to delete the whole row from hbase in my production cluster in two ways, 1) I have written a mapreduce program to remove many rows which satisfy certain condition to do that, The key ...
    Mahesh BalijaMahesh Balija
    May 14, 2012 at 4:57 am
    May 14, 2012 at 5:59 pm
  • Hello, I configured 0.23 thanks to cloudavenue's <http://www.thecloudavenue.com/2012/01/getting-started-with-nextgen-mapreduce.html post. My UI seems ok, but reports only one node out of the ten. My ...
    Keren OuaknineKeren Ouaknine
    May 12, 2012 at 11:24 pm
    May 13, 2012 at 5:04 am
  • do i understand it correctly that with kerberos enabled the mappers and reducers will be "run as" the actual user that started them? as opposed to the user that runs the tasktracker, which is mapred ...
    Koert KuipersKoert Kuipers
    May 3, 2012 at 11:09 pm
    May 3, 2012 at 11:14 pm
  • Hi, We are using the old API 0.20.2 of cloudera CDH3. When I have the combiner set (just using the reducer class), it works both in the mapper and reducer. In the mapper, it only aggregate a couple ...
    GUOJUN ZhuGUOJUN Zhu
    May 31, 2012 at 5:28 pm
    May 31, 2012 at 5:28 pm
  • Hi All, I am using Mapreduce to scan HBase region to get the rowkey_list that related with one query. In Map period, the mapper outputs partial rowkey_list. In reduce period, the reducer will collect ...
    Liu, Keyan (NSN - CN/Beijing)Liu, Keyan (NSN - CN/Beijing)
    May 28, 2012 at 2:50 pm
    May 28, 2012 at 2:50 pm
  • Hi All, I am using Hadoop 1.0.0. I am trying to write a sample that shows how debug scripts works. To do that, I have written a map reduce job that always fail (by explicitly throwing an exception) ...
    Srinath PereraSrinath Perera
    May 26, 2012 at 2:13 am
    May 26, 2012 at 2:13 am
  • Hi, I have been learning and using Hadoop for the last six months. Have gained insight into MapReduce, HDFS, Pig, Flume and Sqoop. Have been able to process RDBMS data and semi structured text data ...
    Mahadevappa, ShobhaMahadevappa, Shobha
    May 23, 2012 at 5:25 am
    May 23, 2012 at 5:25 am
  • I was referred here by Alan Gates (I'm a committer on the Pig project). I've been dealing some with the intermediate serialization of Pi objects. When serializing, there is generally the time to ...
    Jonathan CoveneyJonathan Coveney
    May 23, 2012 at 12:13 am
    May 23, 2012 at 12:13 am
  • Yeah, finally i get the exact place for my question. Hi, I am newbie in Hadoop. I have successfully installed Hadoop-1.0.1 on my Ubuntu10.04 LTS and i am using Eclipse Indigo for designing Hadoop ...
    Ravi JoshiRavi Joshi
    May 18, 2012 at 11:11 am
    May 18, 2012 at 11:11 am
  • Folks, I thought I'd drop a note and let folks know that I've scheduled a Hadoop YARN/MapReduce meetup during Hadoop Summit, June 2012. The agenda is: # YARN - State of the art # YARN futures - ...
    Arun C MurthyArun C Murthy
    May 14, 2012 at 5:25 pm
    May 14, 2012 at 5:25 pm
  • Hello, I keep on getting a memory error, these are my configuration and their respective errors: Few questions: why is physical memory set to 1.0GB when I actually have 47G on these machines. virtual ...
    Keren OuaknineKeren Ouaknine
    May 14, 2012 at 9:58 am
    May 14, 2012 at 9:58 am
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36 users for May 2012

Sharat attupurath: 8 posts Steve Lewis: 8 posts Arun C Murthy: 7 posts Harsh J: 6 posts Robert Evans: 6 posts Subroto: 6 posts GUOJUN Zhu: 5 posts Trevor Robinson: 5 posts Jeffrey Buell: 4 posts Kasi Subrahmanyam: 4 posts Radim Kolar: 4 posts Devaraj k: 3 posts Hadoop anis: 3 posts Something Something: 3 posts Zuhair Khayyat: 3 posts Ashish vyas: 2 posts Jagat: 2 posts jason Yang: 2 posts Keith Wiley: 2 posts Keren Ouaknine: 2 posts
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