Hadoop Online Quiz

Q 1 - A file in HDFS that is smaller than a single block size

A - Cannot be stored in HDFS.

B - Occupies the full block's size.

C - Occupies only the size it needs and not the full block.

D - Can span over multiple blocks.

Q 2 - What mechanisms Hadoop uses to make namenode resilient to failure.

A - Take backup of filesystem metadata to a local disk and a remote NFS mount.

B - Store the filesystem metadata in cloud.

C - Use a machine with at least 12 CPUs

D - Using expensive and reliable hardware.

Q 3 - The current block location of HDFS where data is being written to,

A - is visible to the client requesting for it.

B - Block locations are never visible to client requests.

C - May or may not be visible to the reader.

D - becomes visible only after the buffered data is committed.

Q 4 - The command to check if Hadoop is up and running is −

A - Jsp

B - Jps

C - Hadoop fs –test

D - None

Q 5 - The namenode knows that the datanode is active using a mechanism known as

A - heartbeats

B - datapulse

C - h-signal

D - Active-pulse

Q 6 - Which of the following is not a goal of HDFS?

A - Fault detection and recovery

B - Handle huge dataset

C - Prevent deletion of data

D - Provide high network bandwidth for data movement

Q 7 - When you increase the number of files stored in HDFS, The memory required by namenode

A - Increases

B - Decreases

C - Remains unchanged

D - May increase or decrease

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 - How does Hadoop process large volumes of data?

A - Hadoop uses a lot of machines in parallel. This optimizes data processing.

B - Hadoop was specifically designed to process large amount of data by taking advantage of MPP hardware.

C - Hadoop ships the code to the data instead of sending the data to the code.

D - Hadoop uses sophisticated caching techniques on name node to speed processing of data.

Q 10 - In order to apply a combiner, what is one property that has to be satisfied by the values emitted from the mapper?

A - Combiner can be applied always to any data

B - Output of the mapper and output of the combiner has to be same key value pair and they can be heterogeneous

C - Output of the mapper and output of the combiner has to be same key value pair. Only if the values satisfy associative and commutative property it can be done.