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MapReduce >> mail # user >> Taktracker in namenode failure


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Re: Taktracker in namenode failure
Hi,
    The problem is with jar file only, to check run any other MR job or
sample wordcount job on namenode tasktracker, if it is running no problem
with namenode tasktracker, if not running there may be problem with
tasktracker configuration, then compare with other node tasktracker
configuration. i.e tasktracker configuration means mapred configuration.

Hi,

From,
Ramesh.
On Fri, Jul 12, 2013 at 3:37 PM, Devaraj k <[EMAIL PROTECTED]> wrote:

>  I think, there is mismatch of jar’s coming in the classpath for the map
> tasks when it runs in different machines. You can find out this, by giving
> some unique name for your Mapper class, Job Submit class and then submit
> the Job.****
>
> ** **
>
> Thanks****
>
> Devaraj k****
>
> ** **
>
> *From:* Ramya S [mailto:[EMAIL PROTECTED]]
> *Sent:* 12 July 2013 15:27
> *To:* [EMAIL PROTECTED]
> *Subject:* RE: Taktracker in namenode failure****
>
>  ** **
>
> Both the map output value  class configured and the output value  written
> from the mapper is Text class. So there is no mismatch in the value class.
> ****
>
>  ****
>
>  But when the same MR program is run with 2 tasktrackers(without
> tasktracker in namenode) exception is not occuring.****
>
>  ****
>
> The problem is only with the tasktracker running in the namenode.****
>
>  ****
>
>  ****
>
>  ****
>
> *Thanks & Regards*****
>
>  ****
>
> *Ramya.S*****
>
> ** **
>  ------------------------------
>
> *From:* Devaraj k [mailto:[EMAIL PROTECTED] <[EMAIL PROTECTED]>]
> *Sent:* Fri 7/12/2013 3:04 PM
> *To:* [EMAIL PROTECTED]
> *Subject:* RE: Taktracker in namenode failure****
>
> Could you tell, what is the Map Output Value class you are configuring
> while submitting Job and what is the type of the value writing from the
> Mapper. If both of these mismatches then it will trow the below error.****
>
>  ****
>
> Thanks****
>
> Devaraj k****
>
>  ****
>
> *From:* Ramya S [mailto:[EMAIL PROTECTED] <[EMAIL PROTECTED]>]
> *Sent:* 12 July 2013 14:46
> *To:* [EMAIL PROTECTED]
> *Subject:* Taktracker in namenode failure****
>
>  ****
>
> Hi,****
>
>  ****
>
> Why only tasktracker in namenode faill during  job execution with error.**
> **
>
> I have attached the snapshot of error screen with this mail****
>
> java.io.IOException: Type mismatch in value from map: expected org.apache.hadoop.io.Text, recieved org.apache.hadoop.io.IntWritable****
>
>         at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:1019)****
>
>         at org.apache.hadoop.mapred.MapTask$NewOutputCollector.write(MapTask.java:691)****
>
>         at org.apache.hadoop.mapreduce.TaskInputOutputContext.write(TaskInputOutputContext.java:80)****
>
>         at WordCount$TokenizerMapper.map(WordCount.java:30)****
>
>         at WordCount$TokenizerMapper.map(WordCount.java:19)****
>
>         at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)****
>
>         at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)****
>
>         at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)****
>
>         at org.apache.hadoop.mapred.Child$4.run(Child.java:255)****
>
>         at java.security.AccessController.doPrivileged(Native Method)****
>
>         at javax.security.auth.Subject.doAs(Subject.java:416)****
>
>         at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)****
>
>         at org.apache.hadoop.mapred.Child.main(Child.java:249)****
>
>  ****
>
> but  this same task is reassigned to another tasktracker and getting executed. why?****
>
>   ****
>
>  ****
>
> *Best Regards,*****
>
> *Ramya*****
>