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?

901

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

903

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

939

How does Mappers run method works?

893

How does MapReduce framework view its input internally?

868

What are the steps involved in MapReduce framework?

980

What is the Job interface in MapReduce framework?

907

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

MRO,

1092

Detail description of the Reducer phases?

852

Can there be no Reducer?

840

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

989

What is the core of the job in MapReduce framework?

849

MapReduce Types and Formats and Setting up a Hadoop Cluster?

905

It can be possible that a Job has 0 reducers?

965

Why Mapreduce output written in local disk?

999

Post New MapReduce Questions

Un-Answered Questions { MapReduce }

What is a MapReduce Combiner?

795

What are the four basic parameters of a reducer?

653

In MapReduce, ideally how many mappers should be configured on a slave?

664

What is sqoop in Hadoop ?

684

What are ‘maps’ and ‘reduces’?

696

How data is spilt in Hadoop?

644

Mention what are the main configuration parameters that user need to specify to run mapreduce job?

731

Is there any point of learning mapreduce, then?

646

How to configure the number of the Combiner in MapReduce?

625

how is data partitioned before it is sent to the reducer if no custom partitioner is defined in Hadoop?

782

how Hadoop is different from other data processing tools?

646

What is heartbeat in hdfs?

646

Explain the Reducer's reduce phase?

1054

Is it legal to set the number of reducer task to zero? Where the output will be stored in this case?

662

what is storage and compute nodes?

736

For More Un-Answered { MapReduce } Questions Click Here