Hadoop Questions and Answers Java Interface
Posted by Superadmin on December 09 2015 16:24:53

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1. In order to read any file in HDFS, instance of __________ is required.
a) filesystem
b) datastream
c) outstream
d) inputstream


2. Point out the correct statement :
a) The framework groups Reducer inputs by keys
b) The shuffle and sort phases occur simultaneously i.e. while outputs are being fetched they are merged
c) Since JobConf.setOutputKeyComparatorClass(Class) can be used to control how intermediate keys are grouped, these can be used in conjunction to simulate secondary sort on values
d) All of the mentioned


3. ______________ is method to copy byte from input stream to any other stream in Hadoop.
a) IOUtils
b) Utils
c) IUtils
d) All of the mentioned
View Answer

4. _____________ is used to read data from bytes buffers .
a) write()
b) read()
c) readwrite()
d) All of the mentioned


5. Point out the wrong statement :
a) The framework calls reduce method for each pair in the grouped inputs
b) The output of the Reducer is re-sorted
c) reduce method reduces values for a given key
d) None of the mentioned


6. Interface ____________ reduces a set of intermediate values which share a key to a smaller set of values.
a) Mapper
b) Reducer
c) Writable
d) Readable


7. Reducer is input the grouped output of a :
a) Mapper
b) Reducer
c) Writable
d) Readable


8. The output of the reduce task is typically written to the FileSystem via :
a) OutputCollector
b) InputCollector
c) OutputCollect
d) All of the mentioned


9. Applications can use the _________ provided to report progress or just indicate that they are alive.

a) Collector
b) Reporter
c) Dashboard
d) None of the mentioned



10. Which of the following parameter is to collect keys and combined values ?
a) key
b) values
c) reporter
d) output