Solution should be: 0:1 Migrate(vm2, n1, n4); 0:1 Migrate(vm3, n2, n4); 1:2 Migrate(vm4, n2, n1); 2:3 Shutdown(n2);

SpreadEvaluation.java

    @Test
    public void spreadBasicEvaluation() {
        Mapping map = new MappingBuilder().on(n1, n2, n3, n4)
                .run(n1, vm1, vm2)
                .run(n2, vm3, vm4)
                .run(n3, vm5, vm6).build();

        ShareableResource cpu = new ShareableResource("cpu", 1);
        cpu.set(n1, 4);
        cpu.set(n2, 4);
        cpu.set(n3, 2);
        cpu.set(n4, 4);
        cpu.set(vm2, 2);

        ShareableResource mem = new ShareableResource("mem", 1);
        mem.set(n1, 4);
        mem.set(n2, 4);
        mem.set(n3, 4);
        mem.set(n4, 2);
        mem.set(vm4, 2);
        mem.set(vm6, 2);

        Model model = new DefaultModel(map);
        model.attach(cpu);
        model.attach(mem);
        log.info(model.toString());

        Set<SatConstraint> ctrs = new HashSet<SatConstraint>();
        Set<SatConstraint> ctrsC = new HashSet<SatConstraint>();
        Set<UUID> vms1 = new HashSet<UUID>(Arrays.asList(vm1, vm3, vm5));
        Set<UUID> vms2 = new HashSet<UUID>(Arrays.asList(vm2, vm4, vm6));

        ctrs.add(new Spread(vms1, false));
        ctrs.add(new Spread(vms2, false));

        ctrsC.add(new Spread(vms1));
        ctrsC.add(new Spread(vms2));

        Offline off = new Offline(new HashSet<UUID>() {{
            add(n2);
        }});
        ctrs.add(off);
        ctrsC.add(off);
        ChocoReconfigurationAlgorithm cra = new DefaultChocoReconfigurationAlgorithm();
        try {
            ReconfigurationPlan dp = cra.solve(model, ctrs);
            if (!satisfy(dp, ctrsC)) {
                ReconfigurationPlan cp = cra.solve(model, ctrsC);
                if (!satisfy(cp, ctrsC)) {
                    log.info("Not found continuous plan");
                } else log.info(cp.toString());
            }
        } catch (SolverException e) {
            e.printStackTrace();
        }
    }

    private boolean satisfy(ReconfigurationPlan dp, Set<SatConstraint> constraints) {

        for (SatConstraint sc : constraints) {
            if (sc.isSatisfied(dp)) {
                log.info("Satisfy: " + sc);
            } else {
                log.info("Not Satisfy: " + sc);
                return false;
            }
        }
        return true;
    }