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Accumulo >> mail # user >> Accumulo Map Reduce is not distributed

Cornish, Duane C. 2012-11-02, 20:53
John Vines 2012-11-02, 21:04
Cornish, Duane C. 2012-11-02, 21:21
William Slacum 2012-11-03, 00:48
David Medinets 2012-11-03, 03:49
Cornish, Duane C. 2012-11-05, 13:56
John Vines 2012-11-05, 14:13
Billie Rinaldi 2012-11-05, 14:40
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RE: Accumulo Map Reduce is not distributed

I think I just started to come to that same conclusion (I'm relatively new to cloud computing).  It appears that it is running in local mode.  My console output says "mapred.LocalJobRunner" and the job never appears on my Hadoop Job page.  How do I fix this problem?  I also found that the "JobTracker" link on my Accumulo Overview page points to  instead of the actual computer name.


From: Billie Rinaldi [mailto:[EMAIL PROTECTED]]
Sent: Monday, November 05, 2012 9:41 AM
Subject: Re: Accumulo Map Reduce is not distributed

On Mon, Nov 5, 2012 at 6:13 AM, John Vines <[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>> wrote:

So it sounds like the job was correctly set to 4 mappers and your issue is in your MapReduce configuration. I would check the jobtracker page and verify the number of map slots, as well as how they're running, as print statements are not the most accurate in the framework.

Also make sure your MR job isn't running in local mode.  Sometimes that happens if your job can't find the Hadoop configuration directory.


Sent from my phone, pardon the typos and brevity.
On Nov 5, 2012 8:59 AM, "Cornish, Duane C." <[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>> wrote:
Hi William,

Thanks for helping me out and sorry I didn't get back to you sooner, I was away for the weekend.  I am only callying ToolRunner.run once.

public static void ExtractFeaturesFromNewImages() throws Exception{
              String[] parameters = new String[1];
              parameters[0] = "foo";
              ToolRunner.run(CachedConfiguration.getInstance(), new Accumulo_FE_MR_Job(), parameters);

Another indicator that I'm only calling it once is that before I was pre-splitting the table, I was just getting one larger map-reduce job with only 1 mapper.  Based on my print statements, the job was running in sequence (which I guess makes sense because the table only existed on one node in my cluster.  Then after pre-splitting my table, I was getting one job that had 4 mappers.  Each was running one after the other.  I hadn't changed any code (other than adding in the splits).  So, I'm only calling ToolRunner.run once.  Furthermore, my run function in my job class is provided below:

       public int run(String[] arg0) throws Exception {
              return 0;

From: William Slacum [mailto:[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>]
Sent: Friday, November 02, 2012 8:48 PM
Subject: Re: Accumulo Map Reduce is not distributed

What about the main method that calls ToolRunner.run? If you have 4 jobs being created, then you're calling run(String[]) or runOneTable() 4 times.
On Fri, Nov 2, 2012 at 5:21 PM, Cornish, Duane C. <[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>> wrote:
Thanks for the prompt response John!
When I say that I'm pre-splitting my table, I mean I am using the tableOperations().addSplits(table,splits) command.  I have verified that this is correctly splitting my table into 4 tablets and it is being distributed across my cloud before I start my map reduce job.

Now, I only kick off the job once, but it appears that 4 separate jobs run (one after the other).  The first one reaches 100% in its map phase (and based on my output only handled ¼ of the data), then the next job starts at 0% and reaches 100%, and so on.  So I think I'm "only running one mapper at a time in an MR job that has 4 mappers total.".  I have 2 mapper slots per node.  My hadoop is set up so that one machine is the namenode and the other 3 are datanodes.  This gives me 6 slots total.  (This is not congruent to my accumulo where the master is also a slave - giving 4 total slaves).

My map reduce job is not a chain job, so all 4 tablets should be able to run at the same time.

Here is my job class code below:

import org.apache.accumulo.core.security.Authorizations;
import org.apache.accumulo.core.client.mapreduce.AccumuloOutputFormat;
import org.apache.accumulo.core.client.mapreduce.AccumuloRowInputFormat;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.util.Tool;
import org.apache.log4j.Level;
public class Accumulo_FE_MR_Job extends Configured implements Tool{

       private void runOneTable() throws Exception {
        System.out.println("Running Map Reduce Feature Extraction Job");

        Job job  = new Job(getConf(), getClass().getName());



                new Authorizations());

        AccumuloRowInputFormat.setLogLevel(job.getConfiguration(), Level.FATAL);



Billie Rinaldi 2012-11-05, 15:03
Cornish, Duane C. 2012-11-05, 16:54
Krishmin Rai 2012-11-05, 17:14
Billie Rinaldi 2012-11-05, 17:18
Cornish, Duane C. 2012-11-06, 13:45
David Medinets 2012-11-06, 14:34
Cornish, Duane C. 2012-11-06, 14:53
Billie Rinaldi 2012-11-06, 15:19
David Medinets 2012-11-05, 15:16
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB