top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

How to write a custom partitioner for a Hadoop MapReduce job?

+1 vote
510 views
How to write a custom partitioner for a Hadoop MapReduce job?
posted Dec 26, 2016 by Karthick.c

Looking for an answer?  Promote on:
Facebook Share Button Twitter Share Button LinkedIn Share Button

Similar Questions
+1 vote
How to stop a mapreduce job from terminal running on Hadoop Cluster?

To run a job we use the command
$ hadoop jar example.jar inputpath outputpath
If job is so time taken and we want to stop it in middle then which command is used? Or is there any other way to do that?

+1 vote
Can we run mapreduce job from eclipse IDE on fully distributed mode hadoop cluster?

A mapreduce job can be run as jar file from terminal or directly from eclipse IDE. When a job run as jar file from terminal it uses multiple jvm and all resources of cluster. Does the same thing happen when we run from IDE. I have run a job on both and it takes less time on IDE than jar file on terminal.

+1 vote
How to set mapreduce.input.fileinputformat.split.maxsize for a specific job ?

In xmls configuration file of Hadoop-2.x, "mapreduce.input.fileinputformat.split.minsize" is given which can be set but how to set "mapreduce.input.fileinputformat.split.maxsize" in xml file. I need to set it in my mapreduce code.

+3 votes
How to partition a file to smaller size for performing KNN in hadoop mapreduce

In KNN like algorithm we need to load model Data into cache for predicting the records.

Here is the example for KNN.

So if the model will be a large file say1 or 2 GB we will be able to load them into Distributed cache.

The one way is to split/partition the model Result into some files and perform the distance calculation for all records in that file and then find the min ditance and max occurance of classlabel and predict the outcome.

How can we parttion the file and perform the operation on these partition ?

ie 1 record  parttition1,partition2,.... 2nd record  parttition1,partition2,...

This is what came to my thought. Is there any further way. Any pointers would help me.

0 votes
How to get info about which data in hdfs or file system that a MapReduce job visits?

I was trying to implement a Hadoop/Spark audit tool, but l met a problem that I can't get the input file location and file name. I can get username, IP address, time, user command, all of these info from hdfs-audit.log. But When I submit a MapReduce job, I can't see input file location neither in Hadoop logs or Hadoop ResourceManager.

Does hadoop have API or log that contains these info through some configuration ?If it have, what should I configure?

...