最新なHortonworks Apache-Hadoop-Developer問題集（110題）、真実試験の問題を全部にカバー！

質問 1：
Which describes how a client reads a file from HDFS?
A. The client contacts the NameNode for the block location(s). The NameNode contacts the DataNode that holds the requested data block. Data is transferred from the DataNode to the NameNode, and then from the NameNode to the client.
B. The client queries the NameNode for the block location(s). The NameNode returns the block location(s) to the client. The client reads the data directory off the DataNode(s).
C. The client queries all DataNodes in parallel. The DataNode that contains the requested data responds directly to the client. The client reads the data directly off the DataNode.
D. The client contacts the NameNode for the block location(s). The NameNode then queries the DataNodes for block locations. The DataNodes respond to the NameNode, and the NameNode redirects the client to the DataNode that holds the requested data block(s). The client then reads the data directly off the DataNode.
正解：B
解説: (Pass4Test メンバーにのみ表示されます)

質問 2：
Consider the following two relations, A and B.

Which Pig statement combines A by its first field and B by its second field?
A. C = JOIN A by al, B by b2;
B. C = DOIN B BY a1, A by b2;
C. C = JOIN A SO, B $1;
D. C = JOIN A a1, B b2;
正解：A

質問 3：
Identify the MapReduce v2 (MRv2 / YARN) daemon responsible for launching application containers and monitoring application resource usage?
A. ApplicationMaster
B. ApplicationMasterService
C. ResourceManager
D. TaskTracker
E. NodeManager
F. JobTracker
正解：E
解説: (Pass4Test メンバーにのみ表示されます)

質問 4：
To use a lava user-defined function (UDF) with Pig what must you do?
A. Define an alias to shorten the function name
B. Pass arguments to the constructor of UDFs implementation class
C. Register the JAR file containing the UDF
D. Put the JAR file into the user's home folder in HDFS
正解：C

質問 5：
You have the following key-value pairs as output from your Map task:
(the, 1) (fox, 1) (faster, 1) (than, 1) (the, 1) (dog, 1)
How many keys will be passed to the Reducer's reduce method?
A. Two
B. Four
C. Six
D. One
E. Three
F. Five
正解：F
解説: (Pass4Test メンバーにのみ表示されます)

質問 6：
Which one of the following statements describes the relationship between the NodeManager and the ApplicationMaster?
A. The NodeManager creates an instance of the ApplicationMaster
B. The NodeManager requests resources from the ApplicationMaster
C. The ApplicationMaster starts the NodeManager outside of a Container
D. The ApplicationMaster starts the NodeManager in a Container
正解：A

質問 7：
A combiner reduces:
A. The number of output files a reducer must produce.
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 input files a mapper must process.
正解：C
解説: (Pass4Test メンバーにのみ表示されます)

質問 8：
Identify the tool best suited to import a portion of a relational database every day as files into HDFS, and generate Java classes to interact with that imported data?
A. Hive
B. Hue
C. Flume
D. Pig
E. Sqoop
F. fuse-dfs
G. Oozie
正解：E
解説: (Pass4Test メンバーにのみ表示されます)

質問 9：
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. There is no difference in output between the two settings.
B. 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.
C. 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.
D. 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.
正解：B
解説: (Pass4Test メンバーにのみ表示されます)