First version

settings.gradle

@@ -11,3 +11,6 @@ include 'uc3-application'
 
 include 'uc4-workload-generator'
 include 'uc4-application'
+
+include 'workload-generator-common'
+include 'test-workload-generator'

test-workload-generator/.directory

+[Dolphin]
+Timestamp=2020,5,12,13,3,57
+Version=4
+
+[Settings]
+HiddenFilesShown=true

test-workload-generator/.settings/org.eclipse.jdt.ui.prefs

+cleanup.add_default_serial_version_id=true
+cleanup.add_generated_serial_version_id=false
+cleanup.add_missing_annotations=true
+cleanup.add_missing_deprecated_annotations=true
+cleanup.add_missing_methods=false
+cleanup.add_missing_nls_tags=false
+cleanup.add_missing_override_annotations=true
+cleanup.add_missing_override_annotations_interface_methods=true
+cleanup.add_serial_version_id=false
+cleanup.always_use_blocks=true
+cleanup.always_use_parentheses_in_expressions=false
+cleanup.always_use_this_for_non_static_field_access=true
+cleanup.always_use_this_for_non_static_method_access=true
+cleanup.convert_functional_interfaces=false
+cleanup.convert_to_enhanced_for_loop=true
+cleanup.correct_indentation=true
+cleanup.format_source_code=true
+cleanup.format_source_code_changes_only=false
+cleanup.insert_inferred_type_arguments=false
+cleanup.make_local_variable_final=true
+cleanup.make_parameters_final=true
+cleanup.make_private_fields_final=true
+cleanup.make_type_abstract_if_missing_method=false
+cleanup.make_variable_declarations_final=true
+cleanup.never_use_blocks=false
+cleanup.never_use_parentheses_in_expressions=true
+cleanup.organize_imports=true
+cleanup.qualify_static_field_accesses_with_declaring_class=false
+cleanup.qualify_static_member_accesses_through_instances_with_declaring_class=true
+cleanup.qualify_static_member_accesses_through_subtypes_with_declaring_class=true
+cleanup.qualify_static_member_accesses_with_declaring_class=true
+cleanup.qualify_static_method_accesses_with_declaring_class=false
+cleanup.remove_private_constructors=true
+cleanup.remove_redundant_modifiers=false
+cleanup.remove_redundant_semicolons=false
+cleanup.remove_redundant_type_arguments=true
+cleanup.remove_trailing_whitespaces=true
+cleanup.remove_trailing_whitespaces_all=true
+cleanup.remove_trailing_whitespaces_ignore_empty=false
+cleanup.remove_unnecessary_casts=true
+cleanup.remove_unnecessary_nls_tags=true
+cleanup.remove_unused_imports=true
+cleanup.remove_unused_local_variables=false
+cleanup.remove_unused_private_fields=true
+cleanup.remove_unused_private_members=false
+cleanup.remove_unused_private_methods=true
+cleanup.remove_unused_private_types=true
+cleanup.sort_members=false
+cleanup.sort_members_all=false
+cleanup.use_anonymous_class_creation=false
+cleanup.use_blocks=true
+cleanup.use_blocks_only_for_return_and_throw=false
+cleanup.use_lambda=true
+cleanup.use_parentheses_in_expressions=true
+cleanup.use_this_for_non_static_field_access=true
+cleanup.use_this_for_non_static_field_access_only_if_necessary=false
+cleanup.use_this_for_non_static_method_access=true
+cleanup.use_this_for_non_static_method_access_only_if_necessary=false
+cleanup_profile=_CAU-SE-Style
+cleanup_settings_version=2
+eclipse.preferences.version=1
+editor_save_participant_org.eclipse.jdt.ui.postsavelistener.cleanup=true
+formatter_profile=_CAU-SE-Style
+formatter_settings_version=15
+org.eclipse.jdt.ui.ignorelowercasenames=true
+org.eclipse.jdt.ui.importorder=;
+org.eclipse.jdt.ui.ondemandthreshold=99
+org.eclipse.jdt.ui.staticondemandthreshold=99
+sp_cleanup.add_default_serial_version_id=true
+sp_cleanup.add_generated_serial_version_id=false
+sp_cleanup.add_missing_annotations=true
+sp_cleanup.add_missing_deprecated_annotations=true
+sp_cleanup.add_missing_methods=false
+sp_cleanup.add_missing_nls_tags=false
+sp_cleanup.add_missing_override_annotations=true
+sp_cleanup.add_missing_override_annotations_interface_methods=true
+sp_cleanup.add_serial_version_id=false
+sp_cleanup.always_use_blocks=true
+sp_cleanup.always_use_parentheses_in_expressions=false
+sp_cleanup.always_use_this_for_non_static_field_access=true
+sp_cleanup.always_use_this_for_non_static_method_access=true
+sp_cleanup.convert_functional_interfaces=false
+sp_cleanup.convert_to_enhanced_for_loop=true
+sp_cleanup.correct_indentation=true
+sp_cleanup.format_source_code=true
+sp_cleanup.format_source_code_changes_only=false
+sp_cleanup.insert_inferred_type_arguments=false
+sp_cleanup.make_local_variable_final=true
+sp_cleanup.make_parameters_final=true
+sp_cleanup.make_private_fields_final=true
+sp_cleanup.make_type_abstract_if_missing_method=false
+sp_cleanup.make_variable_declarations_final=true
+sp_cleanup.never_use_blocks=false
+sp_cleanup.never_use_parentheses_in_expressions=true
+sp_cleanup.on_save_use_additional_actions=true
+sp_cleanup.organize_imports=true
+sp_cleanup.qualify_static_field_accesses_with_declaring_class=false
+sp_cleanup.qualify_static_member_accesses_through_instances_with_declaring_class=true
+sp_cleanup.qualify_static_member_accesses_through_subtypes_with_declaring_class=true
+sp_cleanup.qualify_static_member_accesses_with_declaring_class=true
+sp_cleanup.qualify_static_method_accesses_with_declaring_class=false
+sp_cleanup.remove_private_constructors=true
+sp_cleanup.remove_redundant_modifiers=false
+sp_cleanup.remove_redundant_semicolons=true
+sp_cleanup.remove_redundant_type_arguments=true
+sp_cleanup.remove_trailing_whitespaces=true
+sp_cleanup.remove_trailing_whitespaces_all=true
+sp_cleanup.remove_trailing_whitespaces_ignore_empty=false
+sp_cleanup.remove_unnecessary_casts=true
+sp_cleanup.remove_unnecessary_nls_tags=true
+sp_cleanup.remove_unused_imports=true
+sp_cleanup.remove_unused_local_variables=false
+sp_cleanup.remove_unused_private_fields=true
+sp_cleanup.remove_unused_private_members=false
+sp_cleanup.remove_unused_private_methods=true
+sp_cleanup.remove_unused_private_types=true
+sp_cleanup.sort_members=false
+sp_cleanup.sort_members_all=false
+sp_cleanup.use_anonymous_class_creation=false
+sp_cleanup.use_blocks=true
+sp_cleanup.use_blocks_only_for_return_and_throw=false
+sp_cleanup.use_lambda=true
+sp_cleanup.use_parentheses_in_expressions=true
+sp_cleanup.use_this_for_non_static_field_access=true
+sp_cleanup.use_this_for_non_static_field_access_only_if_necessary=false
+sp_cleanup.use_this_for_non_static_method_access=true
+sp_cleanup.use_this_for_non_static_method_access_only_if_necessary=false

test-workload-generator/.settings/qa.eclipse.plugin.checkstyle.prefs

+configFilePath=../config/checkstyle.xml
+customModulesJarPaths=
+eclipse.preferences.version=1
+enabled=true

test-workload-generator/.settings/qa.eclipse.plugin.pmd.prefs

+customRulesJars=
+eclipse.preferences.version=1
+enabled=true
+ruleSetFilePath=../config/pmd.xml

test-workload-generator/build.gradle

+apply plugin: 'application'
+apply plugin: 'eclipse'
+
+buildscript {
+  repositories {
+    maven {
+      url "https://plugins.gradle.org/m2/"
+    }
+  }
+}
+
+sourceCompatibility = "1.11"
+targetCompatibility = "1.11"
+
+dependencies {
+    compile project(':')
+    compile 'org.slf4j:slf4j-simple:1.6.1'
+        
+
+    // Use JUnit test framework
+    testCompile 'junit:junit:4.12'
+}
+
+mainClassName = "test.Main"
+
+eclipse {
+    classpath {
+       downloadSources=true
+       downloadJavadoc=true
+    }
+}

test-workload-generator/docker-compose.yml

+version: '3.1'
+
+services:
+  zookeeper:
+    image: zookeeper
+    ports:
+      - 2181:2181

test-workload-generator/src/main/java/test/Main.java

+package test;
+
+import common.KafkaWorkloadGenerator;
+import common.KafkaWorkloadGeneratorBuilder;
+import common.dimensions.Duration;
+import common.dimensions.KeySpace;
+import common.dimensions.Period;
+import common.messages.OutputMessage;
+import java.util.concurrent.TimeUnit;
+import titan.ccp.models.records.ActivePowerRecord;
+
+public class Main {
+
+  public static void main(final String[] args) {
+
+    final KafkaWorkloadGenerator generator =
+        KafkaWorkloadGeneratorBuilder.builder()
+            .setBeforeHook(() -> {
+              System.out.println("Before Hook");
+            })
+            .setKeySpace(new KeySpace(5))
+            .setPeriod(new Period(1000, TimeUnit.MILLISECONDS))
+            .setDuration(new Duration(60, TimeUnit.SECONDS))
+            .setGeneratorFunction(
+                key -> new OutputMessage(key, new ActivePowerRecord(key, 0L, 100d)))
+            .build();
+
+    generator.start();
+  }
+
+}

workload-generator-common/build.gradle

+apply plugin: 'java-library'
+apply plugin: 'eclipse'
+
+buildscript {
+  repositories {
+    maven {
+      url "https://plugins.gradle.org/m2/"
+    }
+  }
+}
+
+sourceCompatibility = "1.11"
+targetCompatibility = "1.11"
+
+dependencies {
+    compile project(':')
+    compile 'org.apache.curator:curator-recipes:4.3.0'
+    compile 'org.slf4j:slf4j-simple:1.6.1'
+
+    // Use JUnit test framework
+    testCompile 'junit:junit:4.12'
+}
+
+eclipse {
+    classpath {
+       downloadSources=true
+       downloadJavadoc=true
+    }
+}
\ No newline at end of file

workload-generator-common/gradle/wrapper/gradle-wrapper.properties

+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

workload-generator-common/gradlew

+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

workload-generator-common/gradlew.bat

+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

workload-generator-common/settings.gradle

+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * The settings file is used to specify which projects to include in your build.
+ * 
+ * Detailed information about configuring a multi-project build in Gradle can be found
+ * in the user guide at https://docs.gradle.org/4.10.2/userguide/multi_project_builds.html
+ */
+
+rootProject.name = 'workload-generator-common'

workload-generator-common/src/main/java/common/IWorkloadGenerator.java

+package common;
+
+public interface IWorkloadGenerator {
+
+  
+  public void start();
+  public void stop();
+  
+  
+}

workload-generator-common/src/main/java/common/KafkaWorkloadGenerator.java

+package common;
+
+import common.dimensions.Duration;
+import common.dimensions.KeySpace;
+import common.dimensions.Period;
+import common.functions.BeforeAction;
+import common.functions.MessageGenerator;
+import communication.kafka.KafkaRecordSender;
+import titan.ccp.models.records.ActivePowerRecord;
+
+public class KafkaWorkloadGenerator extends WorkloadGenerator {
+  
+  private final KafkaRecordSender<ActivePowerRecord> recordSender;
+  
+  public KafkaWorkloadGenerator(
+      final KeySpace keySpace,
+      final Period period,
+      final Duration duration,
+      final BeforeAction beforeHook,
+      final MessageGenerator generatorFunction,
+      final KafkaRecordSender<ActivePowerRecord> recordSender
+      ) {
+    super(keySpace, period, duration, beforeHook, generatorFunction, outputMessage -> {
+      //recordSender.write(outputMessage.getValue()); removed for dev
+      System.out.println(outputMessage.getKey());
+    });
+    this.recordSender = recordSender;
+  }
+
+  
+  @Override
+  public void stop() {
+    System.out.println("subclass terminated");
+   // this.recordSender.terminate();
+    
+    super.stop();
+  }
+}

workload-generator-common/src/main/java/common/KafkaWorkloadGeneratorBuilder.java

+package common;
+
+import java.util.Objects;
+import common.dimensions.Duration;
+import common.dimensions.KeySpace;
+import common.dimensions.Period;
+import common.functions.BeforeAction;
+import common.functions.MessageGenerator;
+import communication.kafka.KafkaRecordSender;
+import titan.ccp.models.records.ActivePowerRecord;
+
+public class KafkaWorkloadGeneratorBuilder {
+        
+  private KeySpace keySpace;
+  
+  private Period period;
+  
+  private Duration duration;
+  
+  private BeforeAction beforeAction;
+  
+  private MessageGenerator generatorFunction;
+  
+  private KafkaRecordSender<ActivePowerRecord> kafkaRecordSender;
+    
+  private KafkaWorkloadGeneratorBuilder() {
+    
+  }
+  
+  public static KafkaWorkloadGeneratorBuilder builder() {
+    return new KafkaWorkloadGeneratorBuilder();
+  }
+  
+  public KafkaWorkloadGeneratorBuilder setBeforeHook(final BeforeAction beforeAction) {
+    this.beforeAction = beforeAction;
+    return this;
+  }
+  
+  public KafkaWorkloadGeneratorBuilder setKeySpace(final KeySpace keySpace) {
+    this.keySpace = keySpace;
+    return this;
+  }
+  
+  public KafkaWorkloadGeneratorBuilder setPeriod(final Period period) {
+    this.period = period;
+    return this;
+  }
+  
+  public KafkaWorkloadGeneratorBuilder setDuration(final Duration duration) {
+    this.duration = duration;
+    return this;
+  }
+  
+  public KafkaWorkloadGeneratorBuilder setGeneratorFunction(final MessageGenerator generatorFunction) {
+    this.generatorFunction = generatorFunction;
+    return this;
+  }
+  
+  public KafkaWorkloadGeneratorBuilder setKafkaRecordSender(final KafkaRecordSender<ActivePowerRecord> kafkaRecordSender) {
+    this.kafkaRecordSender = kafkaRecordSender;
+    return this;
+  }
+  
+  public KafkaWorkloadGenerator build() {
+    Objects.requireNonNull(this.keySpace, "Please specify the key space.");
+    Objects.requireNonNull(this.period, "Please specify the period.");
+    Objects.requireNonNull(this.duration, "Please specify the duration.");
+    final BeforeAction beforeAction = Objects.requireNonNullElse(this.beforeAction, () -> {});
+    Objects.requireNonNull(this.generatorFunction, "Please specify the generator function.");
+    //Objects.requireNonNull(this.kafkaRecordSender, "Please specify the kafka record sender.");
+            
+    return new KafkaWorkloadGenerator(this.keySpace, this.period, this.duration, beforeAction, this.generatorFunction, this.kafkaRecordSender);
+  }
+}

workload-generator-common/src/main/java/common/Worker.java

+package common;
+
+public class Worker {
+  private final int id;
+  
+  public Worker(final int id) {
+    super();
+    this.id = id;
+  }
+  
+  public int getId() {
+    return this.id;
+  }
+  
+}

workload-generator-common/src/main/java/common/WorkloadDeclaration.java

+package common;
+
+import common.dimensions.KeySpace;
+
+public class WorkloadDeclaration {
+  private final KeySpace keySpace;
+  private final int numberOfWorkers;
+  
+  public WorkloadDeclaration(final KeySpace keySpace, final int numberOfWorkers) {
+
+    this.keySpace = keySpace;
+    this.numberOfWorkers = numberOfWorkers;
+  }
+  
+  public KeySpace getKeySpace() {
+    return this.keySpace;
+  }
+  
+  public int getNumberOfWorkers() {
+    return this.numberOfWorkers;
+  }
+  
+  /*
+   * Replace by json format serialization/deserialization
+   */
+  @Override
+  public String toString() {
+    return this.getKeySpace().getPrefix() + ";" + this.getKeySpace().getMin() + ";" + this.getKeySpace().getMax() + ";" + this.getNumberOfWorkers();
+  }
+
+  public static WorkloadDeclaration fromString(String declarationString) {
+    final String[] deserialized = declarationString.split(";");
+ 
+    return new WorkloadDeclaration(new KeySpace(deserialized[0], Integer.valueOf(deserialized[1]), Integer.valueOf(deserialized[2])), Integer.valueOf(deserialized[3]));
+  }
+}