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?

461

What happen when namenode enters in safemode in hadoop?

431

What is shuffleing in mapreduce?

650

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?

680

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.

826

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

667

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?

715

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

657

Give some points of pig for hadoop ?

555

How does master slave architecture in the hadoop?

817

Explain the wordcount implementation via hadoop framework ?

725

What is hadoop framework?

724

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

673

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

615

How to enable recycle bin in hadoop?

766

Un-Answered Questions { Hadoop }

What is Yum?

What is the port number for NameNode

841

Can you join multiple fields in Apache

533

Which file systems does Spark support?

290

What is difference between hadoop and spark?

305

When the reducers are are started in a mapreduce job?

598

What is a Combiner?

744

Can you explain how to minimize data transfers while working with Spark?

539

Hadoop uses replication to achieve fault tolerance. How is this achieved in Apache Spark?

410

How will format the HDFS ?

1074

What are the different CQL data definition commands in Cassandra?

How much Metadata will be created on NameNode in Hadoop?

What is the usage of "void close()" method?

Explain parquet file?

282

What is spooldir flume?

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