| 1 | package de.uka.ipd.sdq.dsexplore.opt4j.optimizer.heuristic.operators.impl; |
| 2 | |
| 3 | import java.util.ArrayList; |
| 4 | import java.util.LinkedList; |
| 5 | import java.util.List; |
| 6 | import java.util.Random; |
| 7 | import java.util.Set; |
| 8 | |
| 9 | import org.eclipse.emf.ecore.EObject; |
| 10 | import org.opt4j.core.problem.Genotype; |
| 11 | import org.opt4j.operator.copy.Copy; |
| 12 | |
| 13 | import de.uka.ipd.sdq.dsexplore.helper.EMFHelper; |
| 14 | import de.uka.ipd.sdq.dsexplore.launch.DSEWorkflowConfiguration; |
| 15 | import de.uka.ipd.sdq.dsexplore.opt4j.optimizer.heuristic.operators.AbstractTactic; |
| 16 | import de.uka.ipd.sdq.dsexplore.opt4j.optimizer.heuristic.operators.TacticsResultCandidate; |
| 17 | import de.uka.ipd.sdq.dsexplore.opt4j.optimizer.heuristic.operators.UtilisationResultCacheAndHelper; |
| 18 | import de.uka.ipd.sdq.dsexplore.opt4j.representation.DSEIndividual; |
| 19 | import de.uka.ipd.sdq.dsexplore.opt4j.representation.DSEIndividualBuilder; |
| 20 | import de.uka.ipd.sdq.dsexplore.qml.handling.QMLConstantsContainer; |
| 21 | import de.uka.ipd.sdq.pcm.designdecision.AllocationDegree; |
| 22 | import de.uka.ipd.sdq.pcm.designdecision.Choice; |
| 23 | import de.uka.ipd.sdq.pcm.designdecision.ClassChoice; |
| 24 | import de.uka.ipd.sdq.pcm.designdecision.ClassDegree; |
| 25 | import de.uka.ipd.sdq.pcm.resourceenvironment.ProcessingResourceSpecification; |
| 26 | import de.uka.ipd.sdq.pcm.resourceenvironment.ResourceContainer; |
| 27 | import de.uka.ipd.sdq.pcm.resourcetype.ResourceType; |
| 28 | import de.uka.ipd.sdq.pcm.resultdecorator.resourceenvironmentdecorator.UtilisationResult; |
| 29 | import de.uka.ipd.sdq.pcm.resultdecorator.resourceenvironmentdecorator.impl.ProcessingResourceSpecificationResultImpl; |
| 30 | |
| 31 | /** |
| 32 | * Implements a reallocation heuristic which allocates a component from |
| 33 | * a highly utilised resource container to a lowly utilised container |
| 34 | * |
| 35 | * TODO: Only works for a single resource type so far. |
| 36 | * |
| 37 | * @author martens, Tom Beyer |
| 38 | * |
| 39 | */ |
| 40 | public class ReallocationImpl extends AbstractTactic { |
| 41 | |
| 42 | /** |
| 43 | * If utilisation is larger than this double it will be considered |
| 44 | * a high utilisation |
| 45 | */ |
| 46 | private double thresholdUtilisationDifference; |
| 47 | |
| 48 | |
| 49 | private Random generator = new Random(); |
| 50 | |
| 51 | private UtilisationResultCacheAndHelper resultsCache = new UtilisationResultCacheAndHelper(); |
| 52 | |
| 53 | /** |
| 54 | * |
| 55 | * @param copy Used to copy genotype |
| 56 | * @param individualBuilder Used to build individual |
| 57 | */ |
| 58 | public ReallocationImpl(Copy<Genotype> copy, DSEIndividualBuilder individualBuilder, DSEWorkflowConfiguration configuration) { |
| 59 | super(copy, individualBuilder, configuration, new String[] {QMLConstantsContainer.QUALITY_ATTRIBUTE_DIMENSION_RESPONSETIME_DEFINITION_PATH, |
| 60 | QMLConstantsContainer.QUALITY_ATTRIBUTE_DIMENSION_THROUGHPUT_DEFINITION_PATH}); |
| 61 | // set config |
| 62 | setHeuristicWeight(configuration.getReallocationWeight()); |
| 63 | thresholdUtilisationDifference = configuration.getReallocationThresholdUtilisationDifference(); |
| 64 | } |
| 65 | |
| 66 | |
| 67 | /** |
| 68 | * Check whether there is one server with high utilization |
| 69 | * and one with low utilization which are both not null |
| 70 | * @param individual Individual to check |
| 71 | * @param resourceType |
| 72 | */ |
| 73 | public boolean doesMatchPrecondition(DSEIndividual individual, ResourceType resourceType) { |
| 74 | UtilisationResult minUtilisationResult = resultsCache.getMinProcUtilisationResult(individual, resourceType); |
| 75 | UtilisationResult maxUtilisationResult = resultsCache.getMaxProcUtilisationResult(individual, resourceType); |
| 76 | return minUtilisationResult != null && maxUtilisationResult != null && |
| 77 | maxUtilisationResult.getResourceUtilisation() - minUtilisationResult.getResourceUtilisation() |
| 78 | >= thresholdUtilisationDifference ; |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * Generates collection of candidates by applying the reallocation heuristic |
| 83 | * @param individual Individual which the heuristic should be applied to |
| 84 | */ |
| 85 | public List<TacticsResultCandidate> getHeuristicCandidates(DSEIndividual individual, UtilisationResultCacheAndHelper resultCache) { |
| 86 | this.resultsCache = resultCache; |
| 87 | |
| 88 | // return value |
| 89 | List<TacticsResultCandidate> candidates = new ArrayList<TacticsResultCandidate>(); |
| 90 | |
| 91 | // for all used resource types |
| 92 | Set<ResourceType> resourceTypes = this.resultsCache.getResourceTypes(individual); |
| 93 | |
| 94 | for (ResourceType resourceType : resourceTypes) { |
| 95 | |
| 96 | if (doesMatchPrecondition(individual, resourceType)){ |
| 97 | // create new candidate (find servers), set priority and add to list candidates |
| 98 | UtilisationResult minUtilisationResult = resultsCache.getMinProcUtilisationResult(individual, resourceType); |
| 99 | UtilisationResult maxUtilisationResult = resultCache.getMaxProcUtilisationResult(individual, resourceType); |
| 100 | // create candidate |
| 101 | TacticsResultCandidate candidate = individualBuilder.buildCandidate(copy.copy(individual.getGenotype()), individual); |
| 102 | ProcessingResourceSpecification minProcessingResourceSpec = ((ProcessingResourceSpecificationResultImpl)minUtilisationResult).getProcessingResourceSpecification_ProcessingResourceSpecificationResult(); |
| 103 | ProcessingResourceSpecification maxProcessingResourceSpec = ((ProcessingResourceSpecificationResultImpl)maxUtilisationResult).getProcessingResourceSpecification_ProcessingResourceSpecificationResult(); |
| 104 | ResourceContainer targetResourceContainer = ((ResourceContainer)minProcessingResourceSpec.eContainer()); |
| 105 | ResourceContainer sourceResourceContainer = ((ResourceContainer)maxProcessingResourceSpec.eContainer()); |
| 106 | if (EMFHelper.checkIdentity(targetResourceContainer, sourceResourceContainer)) { |
| 107 | return candidates; |
| 108 | } |
| 109 | |
| 110 | List<ClassChoice> potentiallyReallocatedComponents = new LinkedList<ClassChoice>(); |
| 111 | // iterate through choices and change AllocationDegree |
| 112 | for (Choice choice : candidate.getGenotype()) { |
| 113 | if (choice instanceof ClassChoice) { |
| 114 | ClassChoice classChoice = (ClassChoice)choice; |
| 115 | if (classChoice.getDegreeOfFreedomInstance() instanceof AllocationDegree) { |
| 116 | AllocationDegree allocationDegree = (AllocationDegree)classChoice.getDegreeOfFreedomInstance(); |
| 117 | if (EMFHelper.checkIdentity(classChoice.getChosenValue(), sourceResourceContainer)) { |
| 118 | // check whether this component may be allocated to the minimum one |
| 119 | // XXX: Consider several servers with high or low utilization, as there is not necessarily a component that may be allocated from the highest to the lowest. Also consider second highest / lowest if none for the highest can be found. |
| 120 | for (EObject designOption : allocationDegree.getClassDesignOptions()) { |
| 121 | if (EMFHelper.checkIdentity(targetResourceContainer, designOption)) { |
| 122 | // this degree of freedom allows to allocate to the target container, |
| 123 | // so its component is a possible one to reallocate. |
| 124 | potentiallyReallocatedComponents.add(classChoice); |
| 125 | break; |
| 126 | } |
| 127 | } |
| 128 | } |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | // if the size is one or smaller, there are no components to reallocate. |
| 134 | // we do not want to reallocate a single component (as that s server consolidation). |
| 135 | if (potentiallyReallocatedComponents.size() > 1){ |
| 136 | //reallocate just one component, choose it randomly. TODO: choose it more wisely, e.g. based on its demand. |
| 137 | int chosenComponentIndex = generator.nextInt(potentiallyReallocatedComponents.size()); |
| 138 | ClassChoice componentToReallocate = potentiallyReallocatedComponents.get(chosenComponentIndex); |
| 139 | componentToReallocate.setChosenValue( |
| 140 | EMFHelper.retrieveEntityByID( |
| 141 | ((ClassDegree)componentToReallocate.getDegreeOfFreedomInstance()).getClassDesignOptions(), |
| 142 | targetResourceContainer)); |
| 143 | |
| 144 | candidate.setCandidateWeight(getCandidateWeight(minUtilisationResult, maxUtilisationResult)); |
| 145 | candidate.setHeuristic(this); |
| 146 | candidates.add(candidate); |
| 147 | increaseCounterOfGeneratedCandidates(); |
| 148 | } |
| 149 | |
| 150 | } |
| 151 | } |
| 152 | return candidates; |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | * Calculates weight of the candidate using maxUtil-minUtil |
| 157 | * @param minUtilisationResult UtilisationResult with minimum utilisation |
| 158 | * @param maxUtilisationResult UtilisationResult with maximum utilisation |
| 159 | * @return Weight of candidate |
| 160 | */ |
| 161 | private double getCandidateWeight(UtilisationResult minUtilisationResult, |
| 162 | UtilisationResult maxUtilisationResult) { |
| 163 | return Math.min(1, maxUtilisationResult.getResourceUtilisation() - minUtilisationResult.getResourceUtilisation()); |
| 164 | } |
| 165 | |
| 166 | } |