Hadoop Interview Questions
Questions Answers Views Company eMail

What is MapReduce?

328

What MapReduce framework consists of?

320

Can we submit the mapreduce job from slave node?

360




How can we control particular key should go in a specific reducer?

190

How can you add the arbitrary key-value pairs in your mapper?

303

What is Reduce only jobs?

164

What is a IdentityMapper and IdentityReducer in MapReduce ?

188

Explain Working of MapReduce?

207

Write a Mapreduce Program for Character Count ?

284

how to proceed to write your first mapreducer program?

588

How to set the number of reducers?

514

Developing a MapReduce Application?

198

Different ways of debugging a job in MapReduce?

352

Explain the Reducer's reduce phase?

238

Why do we use HDFS for applications having large data sets and not when there are lot of small files?

1 541







Un-Answered Questions { Hadoop }

How will you merge the contents of two or more relations and divide a single relation into two or more relations?

162


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

185


State the usage of 'filters', 'group' , 'orderBy', 'distinct' keywords in pig scripts?

47


What is the stable version of Hive ?

975


what does the conf.setMapper Class do ?

37






What is Hive query processor?

60


What happens when a datanode fails ?

44


What is the process to change the files at arbitrary locations in HDFS?

497


What is your favourite tool in the hadoop ecosystem?

169


What is a block and block scanner in HDFS?

212


What is HDFS block size and what did you chose in your project?

137


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

174


What are the different operational commands in HBase at record level and table level?

108


What is the communication channel between client and namenode/datanode?

532


How can you overwrite the replication factors in HDFS?

370