Category: Hadoop Basics

MapReduce tries to place the data and the compute as close as possible

Map Task in MapReduce is performed using the Mapper() function

Reduce Task in MapReduce is performed using the Map() function

All Options are Correct

Elastic MapReduce (EMR) is Facebook’s packaged Hadoop offereing

Amazon Web Service Elastic MapReduce (EMR) is Amazon’s packaged Hadoop offering

Scalding is a Scala API on top of Cascading that removes most Java boilerplate

All Options are Correct

DataNode is aware of the files to which the blocks stored on it belong to

Replication Factor can be configured at a cluster level (Default is set to 3) and also at a file level

Block Report from each DataNode contains a list of all the blocks that are stored on that DataNode

User data is stored on the local file system of DataNodes

DataNode is the slave/worker nod e and holds the user data in the form of Data Blocks

Each incoming file is broken into 32MB by default

Data blocks are replicated across different nodes in the cluster to ensure a low degree of fault tolerance

None of the Option is Correct

HashPartitioner

Partitioner

HashPar

None of the Option is Correct

NameNode

Data Node

ActionNode

All Options are Correct

DataNode

NameNode

Data block

Replication

TaskTracker

Mapper

MapReduce

jobTracker

All Options are Correct

Replication Factor is changed

DataNode goes down

Data Blocks get corrupted