FREE Certified Data Professional (Big Data Hadoop Administrator) Questions and Answers

Question 1

When may the reduce method of a certain Reducer be invoked for the first time?

Accepted Answer

Not until all the Mappers have finished processing records

Answer

Before beginning the reduce process, the MapReduce engine makes sure that all of the Mappers have finished their execution.

Question 2

How can a client access a file on HDFS?

Accepted Answer

For the block location, the client contacts the NameNode (s). The NameNode then requests block locations from the DataNodes. The NameNode leads the client to the DataNode, holding the requested data block when the DataNodes react to it (s). Data is then read directly from the DataNode by the client.

Answer

For the block location, the client contacts the NameNode (s). The NameNode then requests block locations from the DataNodes. The NameNode leads the client to the DataNode, holding the requested data block when the DataNodes react to it (s). The data is then immediately read by the client from the DataNode.

Question 3

You are creating a combiner that receives input in text keys and IntWritable values and outputs text keys and IntWritable values. Which interface ought to be implemented by your class?

Accepted Answer

Answer

Reducer <Text, IntWritable, Text, IntWritable> is the correct syntax to implement the class.

Question 4

Which tool enables you to use any executable script as the Mapper or Reducer to generate and run MapReduce jobs?

Accepted Answer

Hadoop Streaming

Answer

MapReduce tasks may be created and executed using any executable script as the Mapper or Reducer by using Hadoop streaming.

Question 5

During a typical sort and shuffle phase of MapReduce, how are keys and data presented and delivered to Reducers?

Accepted Answer

Keys are presented to a Reducer in sorted order; values for a given key are not sorted

Answer

Values for a particular key are not sorted, although keys are delivered to reducers in sorted order.

CDP - Certified Data Professional Practice Test

CDP - Certified Data Professional Practice Test

FREE Certified Data Professional (Big Data Hadoop Administrator) Questions and Answers