FREE Certified Data Professional (Big Data Hadoop Administrator) Questions and Answers
Which tool enables you to use any executable script as the Mapper or Reducer to generate and run MapReduce jobs?
MapReduce tasks may be created and executed using any executable script as the Mapper or Reducer by using Hadoop streaming.
How can a client access a file on HDFS?
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.
Which best reflects the sequence in which data is supplied to a Reducer's reduce function, assuming default settings?
Although the values attached to each key are delivered to a Reducer in sorted order, there is no consistency in the order of the values.
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?
Reducer is the correct syntax to implement the class.
Which Linux command enables the display of a file or directory indication?
Linux users can display a file or directory indication by using the ls -l command.
During a typical sort and shuffle phase of MapReduce, how are keys and data presented and delivered to Reducers?
Values for a particular key are not sorted, although keys are delivered to reducers in sorted order.
When may the reduce method of a certain Reducer be invoked for the first time?
Before beginning the reduce process, the MapReduce engine makes sure that all of the Mappers have finished their execution.