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

MapReduce Interview Questions

Questions Answers Views Company eMail

What is Shuffling and Sorting in a MapReduce?

509

What is the difference between Hadoop and RDBMS?

456

how can you check whether Namenode is working beside using the jps command?

491

Illustrate a simple example of the working of MapReduce.

465

For a Hadoop job, how will you write a custom partitioner?

479

what happens when Hadoop spawned 50 tasks for a job and one of the task failed?

527

what is the Hadoop MapReduce APIs contract for a key and value class?

510

When is it suggested to use a combiner in a MapReduce job?

471

What is the process of changing the split size if there is limited storage space on Commodity Hardware?

502

how Hadoop is different from other data processing tools?

467

List the configuration parameters that have to be specified when running a MapReduce job.

439

what is a sequence file in Hadoop?

505

What are the key differences between Pig vs MapReduce?

434

When is it not recommended to use MapReduce paradigm for large

451

what happens in textinformat ?

488

Post New MapReduce Questions

Un-Answered Questions { MapReduce }

How many Mappers run for a MapReduce job in Hadoop?

448

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

487

How to sort intermediate output based on values in MapReduce?

497

What is the input type/format in MapReduce by default?

848

Explain task granularity

450

What are mapreduce new and old apis while writing map reduce program?. Explain how it works

459

Does mapreduce programming model provide a way for reducers to communicate with each other? In a mapreduce job can a reducer communicate with another reducer?

502

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

731

Why the output of map tasks are stored (spilled ) into local disc and not in hdfs?

496

What is Combiner in MapReduce?

467

Is it possible to search for files using wildcards?

467

Explain Working of MapReduce?

772

Is it possible to split 100 lines of input as a single split in MapReduce?

688

What is the difference between an RDBMS and Hadoop?

494

If reducers do not start before all mappers finish then why does the progress on mapreduce job shows something like map(50%) reduce(10%)? Why reducers progress percentage is displayed when mapper is not finished yet?

545

For More Un-Answered { MapReduce } Questions Click Here