You are developing a combiner that takes as input Text keys, IntWritable values, and emits Text keys, IntWritable values. Which interface should your class implement?

A. Combiner

B. Mapper

C. Reducer

D. Reducer

E. Combiner

How are keys and values presented and passed to the reducers during a standard sort and shuffle phase of MapReduce?

A. Keys are presented to reducer in sorted order; values for a given key are not sorted.

B. Keys are presented to reducer in sorted order; values for a given key are sorted in ascending order.

C. Keys are presented to a reducer in random order; values for a given key are not sorted.

D. Keys are presented to a reducer in random order; values for a given key are sorted in ascending order.

You need to create a job that does frequency analysis on input data. You will do this by writing a Mapper that uses TextInputFormat and splits each value (a line of text from an input file) into individual characters. For each one of these characters, you will emit the character as a key and an InputWritable as the value. As this will produce proportionally more intermediate data than input data, which two resources should you expect to be bottlenecks?

A. Processor and network I/O

B. Disk I/O and network I/O

C. Processor and RAM

D. Processor and disk I/O

You need to move a file titled "weblogs" into HDFS. When you try to copy the file, you can't. You know you have ample space on your DataNodes. Which action should you take to relieve this situation and store more files in HDFS?

A. Increase the block size on all current files in HDFS.

B. Increase the block size on your remaining files.

C. Decrease the block size on your remaining files.

D. Increase the amount of memory for the NameNode.

E. Increase the number of disks (or size) for the NameNode.

F. Decrease the block size on all current files in HDFS.

You want to run Hadoop jobs on your development workstation for testing before you submit them to your production cluster. Which mode of operation in Hadoop allows you to most closely simulate a production cluster while using a single machine?

A. Run all the nodes in your production cluster as virtual machines on your development workstation.

B. Run the hadoop command with the jt local and the fs file:///options.

C. Run the DataNode, TaskTracker, NameNode and JobTracker daemons on a single machine.

D. Run simldooop, the Apache open-source software for simulating Hadoop clusters.