Apache Hadoop and Mapreduce Interview Questions and Answers

Course Curriculum

Chapter 1: Section 1

Lecture 1: Introduction

Lecture 2: How to unzip .gz files in a new directory in hadoop?

Lecture 3: Scenario Based Question

Lecture 4: How does Hadoop Namenode failover process works?

Lecture 5: Scenario Based Question

Lecture 6: Tips to Improve Your Course Taking Experience

Lecture 7: How can we initiate a manual failover when automatic failover is configured?

Lecture 8: When not use Hadoop?

Lecture 9: Is there a simple command for hadoop that can change the name of a file ?

Lecture 10: When To Use Hadoop?

Lecture 11: Scenario Based Question

Chapter 2: Section 2

Lecture 1: Can I have multiple files in HDFS use different block sizes?

Lecture 2: Scenario Based Question

Lecture 3: As we talk about Hadoop is Highly scalable how well does it Scale?

Lecture 4: What platforms and Java versions does Hadoop run on?

Lecture 5: What kind of hardware scales best for Hadoop?

Lecture 6: Is there an easy way to see the status and health of a cluster?

Lecture 7: Scenario Based Question

Lecture 8: Scenario Based Question

Lecture 9: Scenario Based Question

Lecture 10: Scenario Based Question

Chapter 3: Section 3

Lecture 1: I am seeing connection refused in the logs. How do I troubleshoot this?

Lecture 2: Does Hadoop require SSH?

Lecture 3: What does NFS: Cannot create lock on (some dir) mean?

Lecture 4: Scenario Based Question

Lecture 5: Scenario Based Question

Lecture 6: Scenario Based Question

Lecture 7: Scenario Based Question

Lecture 8: Scenario Based Question

Lecture 9: Scenario Based Question

Lecture 10: Scenario Based Question

Chapter 4: Section 4

Lecture 1: What is the purpose of the secondary name-node?

Lecture 2: Scenario Based Question

Lecture 3: How do I set up a hadoop node to use multiple volumes?

Lecture 4: Scenario Based Question

Lecture 5: Does HDFS make block boundaries between records?

Lecture 6: Does Wildcard characters work correctly in FsShell?

Lecture 7: What does "file could only be replicated to 0 nodes, instead of 1" mean?

Lecture 8: Scenario Based Question

Lecture 9: What happens when two clients try to write into the same HDFS file?

Lecture 10: How to limit Data node's disk usage?

Chapter 5: Section 5

Lecture 1: Scenario Based Question

Lecture 2: Scenario Based Question

Lecture 3: On an individual data node, how do you balance the blocks on the disk?

Lecture 4: Scenario Based Question

Lecture 5: Difference between hadoop fs -put and hadoop fs -copyFromLocal?

Lecture 6: Scenario Based Question

Lecture 7: How to check HDFS Directory size?

Lecture 8: Scenario Based Question

Lecture 9: On what concept the Hadoop framework works?

Lecture 10: What is Hadoop streaming?

Chapter 6: Section 6

Lecture 1: Explain about the process of inter cluster data copying.?

Lecture 2: Scenario Based Question

Lecture 3: Differentiate between Structured and Unstructured data?

Lecture 4: Explain the difference between NameNode, Backup Node and Checkpoint NameNode?

Lecture 5: How can you overwrite the replication factors in HDFS?

Lecture 6: What is the process to change the files at arbitrary locations in HDFS?

Lecture 7: Explain about the indexing process in HDFS?

Lecture 8: What is a rack awareness and on what basis is data stored in a rack?

Lecture 9: What happens to a NameNode that has no data?

Lecture 10: Scenario Based Question

Chapter 7: Section 7

Lecture 1: Scenario Based Question

Lecture 2: Whenever a client submits a hadoop job, who receives it?

Lecture 3: What do you understand by edge nodes in Hadoop?

Lecture 4: What are real-time industry applications of Hadoop?

Lecture 5: What all modes Hadoop can be run in?

Lecture 6: Explain the major difference between HDFS block and InputSplit?

Lecture 7: What are the most common Input Formats in Hadoop?

Lecture 8: What is Speculative Execution in Hadoop?

Lecture 9: What is Fault Tolerance?

Lecture 10: What is a heartbeat in HDFS?

Chapter 8: Section 8

Lecture 1: How to keep HDFS cluster balanced?

Lecture 2: How to deal with small files in Hadoop?

Lecture 3: Scenario Based Question

Lecture 4: What type of problems can mapreduce solve?

Lecture 5: What is the difference between Hadoop Map Reduce and Google Map Reduce?

Lecture 6: How to get the input file name in the mapper in a Hadoop program?

Lecture 7: Scenario Based Question

Lecture 8: Scenario Based Question

Lecture 9: Scenario Based Question

Lecture 10: Can you set number of map task in Map reduce?

Chapter 9: Section 9

Lecture 1: If your Mapreduce Job launches 20 task for 1 job can you limit to 10 task?

Lecture 2: Scenario Based Question

Lecture 3: What is Shuffling and Sorting in Hadoop MapReduce?

Lecture 4: How do I submit extra content (jars, static files, etc) for Mapreduce job to use

Lecture 5: How do I get my MapReduce Java Program to read the Cluster's set configuration?

Lecture 6: Explain what happens when Hadoop spawned 50 tasks for a job and one of the task

Lecture 7: What is OutputCommitter?

Lecture 8: What is RecordReader in a Map Reduce?

Lecture 9: What is a MapReduce Combiner?

Lecture 10: What do you understand by the term Straggler ?