HADOOP-PR000007 Online Practice Questions and Answers

Given a directory of files with the following structure: line number, tab character, string: Example: 1abialkjfjkaoasdfjksdlkjhqweroij 2kadfjhuwqounahagtnbvaswslmnbfgy 3kjfteiomndscxeqalkzhtopedkfsikj You want to send each line as one record to your Mapper. Which InputFormat should you use to complete

the line: conf.setInputFormat (____.class) ; ?

A. SequenceFileAsTextInputFormat

B. SequenceFileInputFormat

C. KeyValueFileInputFormat

D. BDBInputFormat

Which HDFS command uploads a local file X into an existing HDFS directory Y?

A. hadoop scp X Y

B. hadoop fs -localPut X Y

C. hadoop fs-put X Y

D. hadoop fs -get X Y

Which two of the following are true about this trivial Pig program' (choose Two)

A. The contents of myfile appear on stdout

B. Pig assumes the contents of myfile are comma delimited

C. ABC has a schema associated with it

D. myfile is read from the user's home directory in HDFS

Analyze each scenario below and indentify which best describes the behavior of the default partitioner?

A. The default partitioner assigns key-values pairs to reduces based on an internal random number generator.

B. The default partitioner implements a round-robin strategy, shuffling the key-value pairs to each reducer in turn. This ensures an event partition of the key space.

C. The default partitioner computes the hash of the key. Hash values between specific ranges are associated with different buckets, and each bucket is assigned to a specific reducer.

D. The default partitioner computes the hash of the key and divides that valule modulo the number of reducers. The result determines the reducer assigned to process the key-value pair.

E. The default partitioner computes the hash of the value and takes the mod of that value with the number of reducers. The result determines the reducer assigned to process the key-value pair.

Which one of the following statements is true regarding a MapReduce job?

A. The job's Partitioner shuffles and sorts all (key.value) pairs and sends the output to all reducers

B. The default Hash Partitioner sends key value pairs with the same key to the same Reducer

C. The reduce method is invoked once for each unique value

D. The Mapper must sort its output of (key.value) pairs in descending order based on value

You want to Ingest log files Into HDFS, which tool would you use?

A. HCatalog

B. Flume

C. Sqoop

D. Ambari

For each input key-value pair, mappers can emit:

A. As many intermediate key-value pairs as designed. There are no restrictions on the types of those key-value pairs (i.e., they can be heterogeneous).

B. As many intermediate key-value pairs as designed, but they cannot be of the same type as the input key-value pair.

C. One intermediate key-value pair, of a different type.

D. One intermediate key-value pair, but of the same type.

E. As many intermediate key-value pairs as designed, as long as all the keys have the same types and all the values have the same type.

Identify the MapReduce v2 (MRv2 / YARN) daemon responsible for launching application containers and monitoring application resource usage?

A. ResourceManager

B. NodeManager

C. ApplicationMaster

D. ApplicationMasterService

E. TaskTracker

F. JobTracker

You wrote a map function that throws a runtime exception when it encounters a control character in input data. The input supplied to your mapper contains twelve such characters totals, spread across five file splits. The first four file splits each have two control characters and the last split has four control characters.

Indentify the number of failed task attempts you can expect when you run the job with mapred.max.map.attempts set to 4:

A. You will have forty-eight failed task attempts

B. You will have seventeen failed task attempts

C. You will have five failed task attempts

D. You will have twelve failed task attempts

E. You will have twenty failed task attempts

Consider the following two relations, A and B.

A Pig JOIN statement that combined relations A by its first field and B by its second field would produce what output?

A. 2 Jim Chris 2 3 Terry 3 4 Brian 4

B. 2 cherry 2 cherry 3 orange 4 peach

C. 2 cherry Jim, Chris 3 orange Terry

4 peach Brian

D. 2 cherry Jim 2 2 cherry Chris 2 3 orange Terry 3 4 peach Brian 4