Hortonworks HDPCD Exam Questions & Answers

You've written a MapReduce job that will process 500 million input records and generated 500 million key-value pairs. The data is not uniformly distributed. Your MapReduce job will create a significant amount of intermediate data that it needs to transfer between mappers and reduces which is a potential bottleneck. A custom implementation of which interface is most likely to reduce the amount of intermediate data transferred across the network?

A. Partitioner

B. OutputFormat

C. WritableComparable

D. Writable

E. InputFormat

F. Combiner

Which one of the following statements describes a Pig bag. tuple, and map, respectively?

A. Unordered collection of maps, ordered collection of tuples, ordered set of key/value pairs

B. Unordered collection of tuples, ordered set of fields, set of key value pairs

C. Ordered set of fields, ordered collection of tuples, ordered collection of maps

D. Ordered collection of maps, ordered collection of bags, and unordered set of key/value pairs

Determine which best describes when the reduce method is first called in a MapReduce job?

A. Reducers start copying intermediate key-value pairs from each Mapper as soon as it has completed. The programmer can configure in the job what percentage of the intermediate data should arrive before the reduce method begins.

B. Reducers start copying intermediate key-value pairs from each Mapper as soon as it has completed. The reduce method is called only after all intermediate data has been copied and sorted.

C. Reduce methods and map methods all start at the beginning of a job, in order to provide optimal performance for map-only or reduce-only jobs.

D. Reducers start copying intermediate key-value pairs from each Mapper as soon as it has completed. The reduce method is called as soon as the intermediate key-value pairs start to arrive.