org.btrplace.scheduler.choco.constraint.CQuarantine Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of scheduler-choco Show documentation

Implementation of the VM scheduler that use the Constraint Programming solver CHOCO to compute solutions.

The newest version!

/*
 * 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.Quarantine;
import org.btrplace.scheduler.SchedulerException;
import org.btrplace.scheduler.choco.Parameters;
import org.btrplace.scheduler.choco.ReconfigurationProblem;
import org.chocosolver.solver.Cause;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.variables.IntVar;

import java.util.Collections;
import java.util.Set;

/**
 * Choco implementation of {@link org.btrplace.model.constraint.Quarantine}.
 *
 * @author Fabien Hermenier
 */
public class CQuarantine implements ChocoConstraint {

  private final Quarantine cstr;

    /**
     * Make a new constraint.
     *
     * @param q the quarantine constraint to rely on
     */
    public CQuarantine(Quarantine q) {
        this.cstr = q;
    }

    @Override
    public boolean inject(Parameters ps, ReconfigurationProblem rp) throws SchedulerException {
        // It is just a composition of a root constraint on the VMs on the given nodes (the zone)
        // plus a ban on the other VMs to prevent them for being hosted in the zone
        Mapping map = rp.getSourceModel().getMapping();
        Node n = cstr.getInvolvedNodes().iterator().next();
        int nIdx = rp.getNode(n);
        for (VM vm : rp.getFutureRunningVMs()) {
            if (n.equals(map.getVMLocation(vm))) {
                IntVar d = rp.getVMAction(vm).getDSlice().getHoster();
                try {
                    d.instantiateTo(nIdx, Cause.Null);
                } catch (ContradictionException e) {
                    rp.getLogger().debug("Unable to root " + vm + " on " + n, e);
                    return false;
                }
            } else {
                IntVar d = rp.getVMAction(vm).getDSlice().getHoster();
                try {
                    d.removeValue(nIdx, Cause.Null);
                } catch (ContradictionException e) {
                    rp.getLogger().debug("Unable to disallow " + vm + " to be hosted on " + n, e);
                    return false;
                }
            }
        }
        return true;
    }

    @Override
    public Set getMisPlacedVMs(Instance i) {
        return Collections.emptySet();
    }

    @Override
    public String toString() {
        return cstr.toString();
    }
}