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

Apache Hadoop (394)
MapReduce (354)
Apache Hive (345)
Apache Pig (225)

Apache Ambari (93)
Apache HCatalog (34)
Apache HDFS Hadoop Distributed File System (214)
Apache Kafka (189)

Hadoop Interview Questions

Questions Answers Views Company eMail

Ideally what should be the block size in hadoop?

496

What happen when namenode enters in safemode in hadoop?

472

What is shuffleing in mapreduce?

699

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?

725

How would you tackle calculating the number of unique visitors for each hour by mining a huge apache log? You can use post processing on the output of the mapreduce job.

897

Describe what happens to a mapreduce job from submission to output?

726

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?

764

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

721

Give some points of pig for hadoop ?

588

How does master slave architecture in the hadoop?

882

Explain the wordcount implementation via hadoop framework ?

765

What is hadoop framework?

762

What is partioner in hadoop? Where does it run,mapper or reducer?

710

What is a task instance in hadoop? Where does it run?

659

How to enable recycle bin in hadoop?

800

Un-Answered Questions { Hadoop }

What is the difference between kafka and mq?

552

Can you use spark to access and analyze data stored in cassandra databases?

325

How do you process big data with spark?

301

Is it necessary to kill the topology while updating the running topology?

626

Who is intended audience to learn HCatalog?

How to create Users in hadoop HDFS?

Mention how can you stop a partition form being queried?

1158

What is the difference between External and Internal Table in Hive?

784

What is the difference between Primary, Partition and Cassandra ?

What is a namenode?

433

what is Bloom Filter is used for in Cassandra?

118

What is a partition in Hive?

954

Whether the output of mapper or output of partitioner written on local disk?

721

What do shuffling do?

718

Which serialization libraries are supported in spark?

349

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