Cloudera Certified Developer for Apache Hadoop 認定 CCD-333 試験問題:

1. Workflows expressed in Oozie can contain:

A) Sequences of MapReduce and Pig. These sequences can be combined with other actions including forks, decision points, and path joins.
B) Sequences of MapReduce jobs only; no Pig or Hive tasks or jobs. These MapReduce sequences can be combined with forks and path joins.
C) Iterative repetition of MapReduce jobs until a desired answer or state is reached.
D) Sequences of MapReduce and Pig jobs. These are limited to linear sequences of actions with exception handlers but no forks.

2. Given a Mapper, Reducer, and Driver class packaged into a jar, which is the correct way of submitting the job to the cluster?

A) jar MyJar.jar
B) jar MyJar.jar MyDriverClass inputdir outputdir
C) hadoop jar class MyJar.jar MyDriverClass inputdir outputdir
D) hadoop jar MyJar.jar MyDriverClass inputdir outputdir

3. In a large MapReduce job with m mappers and r reducers, how many distinct copy operations will there be in the sort/shuffle phase?

A) m
B) r
C) mr (i.e., m to the power of r)
D) mxr (i.e., m multiplied by r)
E) m+r (i.e., m plus r)

4. The Hadoop framework provides a mechanism for coping with machine issues such as faulty configuration or impending hardware failure. MapReduce detects that one or a number of machines are performing poorly and starts more copies of a map or reduce task. All the tasks run simultaneously and the task that finish first are used. This is called:

A) IdentityMapper
B) IdentityReducer
C) Default Partitioner
D) Combiner
E) Speculative Execution

5. In the reducer, the MapReduce API provides you with an iterator over Writable values. Calling the next () method:

A) Returns a reference to a different Writable object each time.
B) Returns a reference to a Writable object. The API leaves unspecified whether this is a reused object or a new object.
C) Returns a reference to the same writable object if the next value is the same as the previous value, or a new writable object otherwise.
D) Returns a reference to the same writable object each time, but populated with different data.
E) Returns a reference to a Writable object from an object pool.

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