MapReduce Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

MapReduce Interview Questions

Questions Answers Views Company eMail

What are combiners? When should I use a combiner in my MapReduce Job?

866

In Map Reduce why map write output to Local Disk instead of HDFS?

867

What is a partitioner and how the user can control which key will go to which reducer?

888

How does Mappers run method works?

838

How does MapReduce framework view its input internally?

829

What are the steps involved in MapReduce framework?

932

What is the Job interface in MapReduce framework?

862

How to overwrite an existing output file during execution of mapreduce jobs?

MRO,

1048

Detail description of the Reducer phases?

810

Can there be no Reducer?

810

What is the utility of using Writable Comparable Custom Class in Map Reduce code?

945

What is the core of the job in MapReduce framework?

795

MapReduce Types and Formats and Setting up a Hadoop Cluster?

876

It can be possible that a Job has 0 reducers?

928

Why Mapreduce output written in local disk?

955

Post New MapReduce Questions

Un-Answered Questions { MapReduce }

Define Writable data types in Hadoop MapReduce?

599

What is a distributed cache in mapreduce framework?

572

Is reduce-only job possible in Hadoop MapReduce?

652

what does the text input format do?

770

How do ‘map’ and ‘reduce’ work?

602

When is the reducers are started in a MapReduce job?

826

Explain about the partitioning, shuffle and sort phase in MapReduce?

776

Different ways of debugging a job in MapReduce?

1060

What comes in Hadoop 2.0 and MapReduce V2 YARN

961

What is the relationship between Job and Task in Hadoop?

616

Map reduce jobs take too long. What can be done to improve the performance of the cluster?

644

What is a TaskInstance?

629

Where the mapper's intermediate data will be stored?

591

How to handle record boundaries in Text files or Sequence files in MapReduce InputSplits?

658

What combiners is and when you should use a combiner in a MapReduce Job?

580

For More Un-Answered { MapReduce } Questions Click Here