Difference between revisions of "Windbag MapReduce Application"

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=Motivation=
 
=Motivation=
A simple Mapper and two simple Collectors reinforce our understanding of how pieces of the MapReduce puzzle can be reused.  Further, we will reduce the value type of Boolean to both an Integer and a Double in two different Collectors.
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A simple Mapper and two simple ClassicReducers reinforce our understanding of how pieces of the MapReduce puzzle can be reused.  Further, we will reduce the value type of List<Boolean> to both an Integer and a Double in separate Reducers.
  
 
=Background=
 
=Background=

Revision as of 18:41, 7 March 2023

Motivation

A simple Mapper and two simple ClassicReducers reinforce our understanding of how pieces of the MapReduce puzzle can be reused. Further, we will reduce the value type of List<Boolean> to both an Integer and a Double in separate Reducers.

Background

A windbag is an exhaustively talkative person. Act I Scene 3 of Hamlet has a famous example.

In this assignment we will try to determine who is the biggest windbag in a particular play with Hamlet and The Importance of Being Earnest serving as two pieces of data.

Code To Implement

WindbagMapper

class: WindbagMapper.java Java.png
methods: map
package: mapreduce.apps.windbag.studio
source folder: student/src/main/java

Note: the WindBagMapper is constructed with an IntPredicate. This IntPredicate's test method should be invoked to determine if a PlayLine's word count qualifies it as a windbag line. You can investigate the PlayLine class to see what information it contains.

method: public void map(PlayLine item, BiConsumer<PlayRole, Boolean> keyValuePairConsumer) Sequential.svg (sequential implementation only)

TrueCountClassicReducer

This Collector reduces to the number of emitted trues.

For example, if a total of eight (8) values were emitted for a particular key and three (3) of them were true:

[false, true, false, false, true, true, false, false]

then the reduced value would be 3

class: TrueCountClassicReducer.java Java.png
methods: reduce
package: mapreduce.apps.windbag.exercise
source folder: student/src/main/java

method: public Integer reduce(List<Boolean> container) Sequential.svg (sequential implementation only)

Attention niels epting.svg Warning:This class inherits from ClassicReducer. Be sure to have completed that studio first.

TruePortionClassicReducer

This Collector reduces to the portion of emitted trues.

For example, if a total of eight (8) values were emitted for a particular key and three (3) of them were true:

[false, true, false, false, true, true, false, false]

then the reduced value would be 0.375

class: TruePortionClassicReducer.java Java.png
methods: reduce
package: mapreduce.apps.windbag.exercise
source folder: student/src/main/java

method: public Double reduce(List<Boolean> container) Sequential.svg (sequential implementation only)

Attention niels epting.svg Warning:This class inherits from ClassicReducer. Be sure to have completed that studio first.

Testing Your Solution

Correctness

class: WindbagStudioTestSuite.java Junit.png
package: mapreduce
source folder: testing/src/test/java

Output

class: WindbagApp.java Noun Project stopwatch icon 386232 cc.svg
package: mapreduce.apps.windbag.client
source folder: src/main/java


           COUNT
===========================
      HAMLET: 27
        KING: 14
    POLONIUS:  7
     HORATIO:  5
     OPHELIA:  2
       GHOST:  2
FIRST PLAYER:  2
     LAERTES:  1
 ROSENCRANTZ:  1
   VOLTEMAND:  1
 PLAYER KING:  1
   GENTLEMAN:  1
PLAYER QUEEN:  1
       QUEEN:  1



          PORTION
===========================
   VOLTEMAND: 1.000000
   GENTLEMAN: 0.333333
 PLAYER KING: 0.250000
FIRST PLAYER: 0.250000
PLAYER QUEEN: 0.200000
       GHOST: 0.142857
        KING: 0.137255
    POLONIUS: 0.081395
      HAMLET: 0.075419
     HORATIO: 0.046729
     OPHELIA: 0.034483
 ROSENCRANTZ: 0.022222
     LAERTES: 0.016129
       QUEEN: 0.014493