
org.btrplace.scheduler.choco.constraint.CRunningCapacity Maven / Gradle / Ivy
/*
* Copyright 2021 The BtrPlace Authors. All rights reserved.
* Use of this source code is governed by a LGPL-style
* license that can be found in the LICENSE.txt file.
*/
package org.btrplace.scheduler.choco.constraint;
import org.btrplace.model.Instance;
import org.btrplace.model.Mapping;
import org.btrplace.model.Node;
import org.btrplace.model.VM;
import org.btrplace.model.constraint.RunningCapacity;
import org.btrplace.scheduler.SchedulerException;
import org.btrplace.scheduler.choco.Parameters;
import org.btrplace.scheduler.choco.ReconfigurationProblem;
import org.chocosolver.solver.Model;
import org.chocosolver.solver.variables.IntVar;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* Choco implementation of {@link org.btrplace.model.constraint.RunningCapacity}.
*
* @author Fabien Hermenier
*/
public class CRunningCapacity implements ChocoConstraint {
private final RunningCapacity cstr;
/**
* Make a new constraint.
*
* @param c the constraint to rely on
*/
public CRunningCapacity(RunningCapacity c) {
cstr = c;
}
@Override
public boolean inject(Parameters ps, ReconfigurationProblem rp) throws SchedulerException {
Model csp = rp.getModel();
if (cstr.getInvolvedNodes().size() == 1) {
return filterWithSingleNode(rp);
}
List vs = new ArrayList<>();
for (Node u : cstr.getInvolvedNodes()) {
vs.add(rp.getNbRunningVMs().get(rp.getNode(u)));
}
//Try to get a lower bound
//basically, we count 1 per VM necessarily in the set of nodes
//if involved nodes == all the nodes, then sum == nb of running VMs
IntVar mySum = csp.intVar(rp.makeVarLabel("nbRunning"), 0, rp.getFutureRunningVMs().size(), true);
csp.post(csp.sum(vs.toArray(new IntVar[vs.size()]), "=", mySum));
csp.post(csp.arithm(mySum, "<=", cstr.getAmount()));
if (cstr.getInvolvedNodes().equals(rp.getSourceModel().getMapping().getAllNodes())) {
csp.post(csp.arithm(mySum, "=", rp.getFutureRunningVMs().size()));
}
return true;
}
private boolean filterWithSingleNode(ReconfigurationProblem rp) {
Node n = cstr.getInvolvedNodes().iterator().next();
IntVar v = rp.getNbRunningVMs().get(rp.getNode(n));
Model csp = rp.getModel();
csp.post(csp.arithm(v, "<=", cstr.getAmount()));
return true;
}
@Override
public Set getMisPlacedVMs(Instance i) {
Mapping map = i.getModel().getMapping();
Set bad = new HashSet<>();
int remainder = cstr.getAmount();
for (Node n : cstr.getInvolvedNodes()) {
remainder -= map.getRunningVMs(n).size();
if (remainder < 0) {
for (Node n2 : cstr.getInvolvedNodes()) {
bad.addAll(map.getRunningVMs(n2));
}
return bad;
}
}
return bad;
}
@Override
public String toString() {
return cstr.toString();
}
}
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