Hadoop Interview Questions
Questions Answers Views Company eMail

What is a "map" in Hadoop?

489

What is a "reducer" in Hadoop?

528

what is Speculative Execution?

516

Explain JobConf in MapReduce.

513

What is OutputCommitter?

496

How is reporting controlled in hadoop?

460

What is Hadoop Map Reduce ?

526

what does the text input format do?

505

What happens when a datanode fails ?

484

In Hadoop, which file controls reporting in Hadoop?

479

how can you debug Hadoop code?

505

For a job in Hadoop, is it possible to change the number of mappers to be created?

480

What are the primary phases of a Reducer?

520

how indexing in HDFS is done?

486

What is the role of a MapReduce partitioner?

497


Un-Answered Questions { Hadoop }

What exactly is apache spark?

197


How Spark uses Akka?

212


Does rdd have schema?

201


Why is spark good?

195


When can you use ALTER KEYSPACE?

58






Define memtable?

54


If you run a select * query in hive, why does it not run mapreduce?

469


What is a scarce system resource?

376


What is difference between hadoop and spark?

186


Explain the different logging levels in cassandra.

51


What combiners are and when you should utilize a combiner in a map reduce job?

343


What is meant by spark in big data?

180


What is the functionality of jobtracker in hadoop? How many instances of a jobtracker run on hadoop cluster?

390


What are benefits of DataFrame in Spark?

229


What are the basics of zookeeper api?

5