Cloudera CCD-410 Question Answer

In a MapReduce job, you want each of your input files processed by a single map task. How do you configure a MapReduce job so that a single map task processes each input file regardless of how many blocks the input file occupies?

A. Increase the parameter that controls minimum split size in the job configuration.
B. Write a custom MapRunner that iterates over all key-value pairs in the entire file.
C. Set the number of mappers equal to the number of input files you want to process.
D. Write a custom FileInputFormat and override the method isSplitable to always return false.

Answer: D


Which process describes the lifecycle of a Mapper?

A. The JobTracker calls the TaskTracker's configure () method, then its map () method and finally its close () method.
B. The TaskTracker spawns a new Mapper to process all records in a single input split.
C. The TaskTracker spawns a new Mapper to process each key-value pair.
D. The JobTracker spawns a new Mapper to process all records in a single file.

Answer: B