Hadoop > mapreduce-user > August 2009

Hello guys, I am a newbie of Hadoop and doing an experiment with Hadoop. My situation is: +My job is expected to run continuously/frequently +My reduce task require a large amount of configuration ...

Does hadoop have the capability of merging multiple mappers(on the same node) output into a single one, to speed up the shuffling phase? Is there a JIRA that I can find more information about it? ...

Hi everyone, I've come across a problem running Map/Reduce on an EC2 cluster, and was wondering if anyone here had any thoughts to what the issue was. I'm running a simple 'sort' M/R job on 40GB from ...

http://www.hadooper.cn/hadoop/cgi-bin/moin.cgi/thirdcfp Time : Sunday, November 15, 2009 City: Beijing, China Sponsored by Yahoo!, Cloudera Organized by hadooper.cn Website: ...

I'm looking at hadoop 0.18 vs 0.20. Why doesn't Partitioner have a setup(JobContext) method ? It seem before it used to be a JobConfigurable. Parameters can be passed statically by the Mapper but ...

Hi all, currently, we try to upgrade from hadoop-0.19 to hadoop-0.20. Therefore, we try to get rid of the deprecated JobConf class and switch to org.apache.hadoop.mapreduce.Job where possible. In ...

Hi... I was reading the HDFS code, and I can't find a way to read the replicated blocks of a block-file. DFS.getFileBlockLocations returns all blocks of a file File = block-a, block-b, ..... block-n. ...

(moved to mapreduce-user) Hey Deepak, There's a slightly dated blog post from Aaron Kimball about how to use DBInputFormat to run a Hadoop MapReduce job over records stored in a database: ...

I think I am missing something big. But, I can't figure out how to migrate to Mapreduce 0.20.0. Here's what I think I know: - The org.apache.hadoop.mapred.* classes are deprecated -- so we shouldn't ...

Hi, My name is Jay from Korea. While running Hadoop cluster with version 0.18.3, I added several machines to the cluster a few days ago. Legacy machines have 2 CPU and 8 GB memories, I set ...

Hey all, Has anyone seen behavior where the number of reduce input records is significantly larger than the number of map output records? There's no combiner involved in the job at hand, and it's not ...

Hi, everyone. How can I split the cluster in subcluster?. I want to break my cluster in regions, for example I'd like to have a region for only sorting, other for only joins, other for only groupby, ...

Hi, Edward J. Yoon Sorry that I found I was not in hama-user maillist. Just joined[?] Xrime is based on Map/Reduce using HDFS to store graph information. It is distributed and parallel. We will ...

Hi all, I'm looking for a way to invoke a Hadoop Job programmatically. Is there any sort of an interface for submitting Jobs to Hadoop besides just the command line or some sort of intermediate file ...

Hi, I have a problem trying to customize the key-value seperator of the reducer output: My Hadoop version: 0.19.2 I'm trying to get the reducer to use ctrl-A to seperate key value pairs. ...