Hadoop Online Quiz

Q 1 - Data locality feature in Hadoop means

A - store the same data across multiple nodes.

B - relocate the data from one node to another.

C - co-locate the data with the computing nodes.

D - Distribute the data across multiple nodes.

Q 2 - When a client communicates with the HDFS file system, it needs to communicate with

A - only the namenode

B - only the data node

C - both the namenode and datanode

D - None of these

Q 3 - The property used to set the default filesystem for Hadoop in core-site.xml is-

A - filesystem.default

B - fs.default

C - fs.defaultFS

D - hdfs.default

Q 4 - Underreplication in HDFS means-

A - No replication is happening in the data nodes.

B - Replication process is very slow in the data nodes.

C - The frequency of replication in data nodes is very low.

D - The number of replicated copies is less than as specified by the replication factor.

Q 5 - The output of a mapper task is

A - The Key-value pair of all the records of the dataset.

B - The Key-value pair of all the records from the input split processed by the mapper

C - Only the sorted Keys from the input split

D - The number of rows processed by the mapper task.

Q 6 - When a file in HDFS is deleted by a user

A - it is lost forever

B - It goes to trash if configured.

C - It becomes hidden from the user but stays in the file system

D - File sin HDFS cannot be deleted

Q 7 - hadoop fs –expunge

A - Gives the list of datanodes

B - Used to delete a file

C - Used to exchange a file between two datanodes.

D - Empties the trash.

Q 8 - A running job in hadoop can

A - Be killed with a command

B - Can never be killed with a command

C - Can be killed only by shutting down the name node

D - Be paused and run again

Q 9 - What is distributed cache?

A - The distributed cache is special component on name node that will cache frequently used data for faster client response. It is used during reduce step.

B - The distributed cache is special component on data node that will cache frequently used data for faster client response. It is used during map step.

C - The distributed cache is a component that caches java objects.

D - The distributed cache is a component that allows developers to deploy jars for Map-Reduce processing.

Q 10 - Which of the following components retrieves the input splits directly from HDFS to determine the number of map tasks?

A - The NameNode.

B - The TaskTrackers.

C - The JobClient.

D - The JobTracker.

E - None of the options is correct.