Hadoop Online Quiz

Q 1 - HDFS block size is larger as compared to the size of the disk blocks so that

A - Only HDFS files can be stored in the disk used.

B - The seek time is maximum

C - Transfer of a large files made of multiple disk blocks is not possible.

D - A single file larger than the disk size can be stored across many disks in the cluster.

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 - For a HDFS directory the replication factor(RF) is

A - same as the RF of the files in that directory

B - Zero

C - 3

D - Does not apply.

Q 4 - Which of the below property gets configured on mapred-site.xml ?

A - Replication factor

B - Directory names to store hdfs files.

C - Host and port where MapReduce task runs.

D - Java Environment variables.

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 - The command “hadoop fs -test -z URI “ gives the result 0 if

A - if the path is a directory

B - if the path is a file

C - if the path is not empty

D - if the file is zero length

Q 7 - In HDFS the files cannot be

A - read

B - deleted

C - executed

D - Archived

Q 8 - In a HDFS system with block size 64MB we store a file which is less than 64MB. Which of the following is true?

A - The file will consume 64MB

B - The file will consume more than 64MB

C - The file will consume less than 64MB.

D - Can not be predicted.

Q 9 - When using HDFS, what occurs when a file is deleted from the command line?

A - It is permanently deleted if trash is enabled.

B - It is placed into a trash directory common to all users for that cluster.

C - It is permanently deleted and the file attributes are recorded in a log file.

D - It is moved into the trash directory of the user who deleted it if trash is enabled.

Q 10 - When writing data to HDFS what is true if the replication factor is three? (Choose 2 answers)

1. Data is written to DataNodes on three separate racks (if Rack Aware).

2. The Data is stored on each DataNode with a separate file which contains a checksum value.

3. Data is written to blocks on three different DataNodes.

4. The Client is returned with a success upon the successful writing of the first block and checksum check.

A - 1 & 3

B - 2 & 3

C - 3 & 4

D - 1 & 4