CCD-410試験無料問題集（60題）「Cloudera Certified Developer for Apache Hadoop (CCDH) 認定」

出題：1

Which process describes the lifecycle of a Mapper?

A. The JobTracker spawns a new Mapper to process all records in a single file.

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 calls the TaskTracker's configure () method, then its map () method and finally its close () method.

正解：B 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：2

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 finish first are used. This is called:

A. IdentityReducer

B. IdentityMapper

C. Combine

D. Default Partitioner

E. Speculative Execution

正解：E 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：3

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 twelve failed task attempts

B. You will have seventeen failed task attempts

C. You will have five failed task attempts

D. You will have twenty failed task attempts

E. You will have forty-eight failed task attempts

正解：D 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：4

You write MapReduce job to process 100 files in HDFS. Your MapReduce algorithm uses TextInputFormat: the mapper applies a regular expression over input values and emits key-values pairs with the key consisting of the matching text, and the value containing the filename and byte offset. Determine the difference between setting the number of reduces to one and settings the number of reducers to zero.

A. With zero reducers, instances of matching patterns are stored in multiple files on HDFS. With one reducer, all instances of matching patterns are gathered together in one file on HDFS.

B. With zero reducers, all instances of matching patterns are gathered together in one file on HDFS. With one reducer, instances of matching patterns are stored in multiple files on HDFS.

C. With zero reducers, no reducer runs and the job throws an exception. With one reducer, instances of matching patterns are stored in a single file on HDFS.

D. There is no difference in output between the two settings.

正解：A 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：5

You need to perform statistical analysis in your MapReduce job and would like to call methods in the Apache Commons Math library, which is distributed as a 1.3 megabyte Java archive (JAR) file. Which is the best way to make this library available to your MapReducer job at runtime?

A. Have your system administrator place the JAR file on a Web server accessible to all cluster nodes and then set the HTTP_JAR_URL environment variable to its location.

B. Package your code and the Apache Commands Math library into a zip file named JobJar.zip

C. Have your system administrator copy the JAR to all nodes in the cluster and set its location in the HADOOP_CLASSPATH environment variable before you submit your job.

D. When submitting the job on the command line, specify the -libjars option followed by the JAR file path.

正解：D 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：6

A combiner reduces:

A. The number of input files a mapper must process.

B. The number of values across different keys in the iterator supplied to a single reduce method call.

C. The amount of intermediate data that must be transferred between the mapper and reducer.

D. The number of output files a reducer must produce.

正解：C 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

CCD-410試験無料問題集「Cloudera Certified Developer for Apache Hadoop (CCDH) 認定」