Why is using Combiner function not preferred in shuffling

0 votes
Though a combiner function reduces the shuffling, it is not a preferred method and merging keys are used instead. My question is, why is it not preferred?
Jan 23, 2019 in Big Data Hadoop by slayer
• 29,350 points
582 views

1 answer to this question.

0 votes

Combiner function is not preferred because when a Combiner function is used, there is no way of controlling how many times and if at all Combiner will actually be used.
The default Shuffle & Sort mechanism is based on alphabetical sorting and hash shuffling of the keys and is preferred over Combiner function.

answered Jan 23, 2019 by Omkar
• 69,210 points

Related Questions In Big Data Hadoop

0 votes
1 answer

Why Hadoop is not implemented using Message Passing Interface (MPI)?

One of the big features of Hadoop/map-reduce ...READ MORE

answered Sep 21, 2018 in Big Data Hadoop by Frankie
• 9,830 points
579 views
0 votes
1 answer

Why Hadoop is not implemented using MPI?

 One of the big features of Hadoop/map-reduce ...READ MORE

answered Dec 4, 2018 in Big Data Hadoop by Frankie
• 9,830 points
574 views
0 votes
1 answer

What is Custom partitioner in Hadoop? How to write partition function ?

Don't think that in Hadoop the same ...READ MORE

answered Sep 18, 2018 in Big Data Hadoop by Frankie
• 9,830 points
1,357 views
0 votes
1 answer
+1 vote
1 answer

Hadoop Mapreduce word count Program

Firstly you need to understand the concept ...READ MORE

answered Mar 16, 2018 in Data Analytics by nitinrawat895
• 11,380 points
10,560 views
0 votes
1 answer

hadoop.mapred vs hadoop.mapreduce?

org.apache.hadoop.mapred is the Old API  org.apache.hadoop.mapreduce is the ...READ MORE

answered Mar 16, 2018 in Data Analytics by nitinrawat895
• 11,380 points
2,185 views
+2 votes
11 answers

hadoop fs -put command?

Hi, You can create one directory in HDFS ...READ MORE

answered Mar 16, 2018 in Big Data Hadoop by nitinrawat895
• 11,380 points
104,222 views
–1 vote
1 answer

Hadoop dfs -ls command?

In your case there is no difference ...READ MORE

answered Mar 16, 2018 in Big Data Hadoop by kurt_cobain
• 9,390 points
4,261 views
–1 vote
1 answer

Hadoop cluster is not running in vm

First check if all daemons are running: sudo ...READ MORE

answered Dec 26, 2018 in Big Data Hadoop by Omkar
• 69,210 points
568 views
–1 vote
1 answer

Why is Hive not good for OLTP?

Apache Hive is mainly used for batch processing i.e. ...READ MORE

answered Jan 7, 2019 in Big Data Hadoop by Omkar
• 69,210 points
5,835 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP