Examples with MinMTTRMig org.btrplace.model.constraint.migration.MinMTTRMig used on opensource projects

Example 1 with MinMTTRMig

use of org.btrplace.model.constraint.migration.MinMTTRMig in project scheduler by btrplace.

the class UCC15 method decommissioning_40gb.

public SolvingStatistics decommissioning_40gb() throws SchedulerException {
    // Set nb of nodes and vms
    int nbNodesRack = 24;
    int nbSrcNodes = nbNodesRack * 8;
    int nbDstNodes = nbNodesRack * 4;
    int nbVMs = nbSrcNodes * 2;
    // Set mem + cpu for VMs and Nodes
    int memVM = 4;
    int cpuVM = 1;
    int memSrcNode = 16;
    int cpuSrcNode = 4;
    int memDstNode = 16;
    int cpuDstNode = 4;
    // Set memoryUsed and dirtyRate (for all VMs)
    int tpl1MemUsed = 2000;
    int tpl1MaxDirtySize = 5;
    int tpl1MaxDirtyDuration = 3;
    // idle vm
    double tpl1DirtyRate = 0;
    int tpl2MemUsed = 4000;
    int tpl2MaxDirtySize = 96;
    int tpl2MaxDirtyDuration = 2;
    // stress --vm 1000 --bytes 70K
    double tpl2DirtyRate = 3;
    int tpl3MemUsed = 2000;
    int tpl3MaxDirtySize = 96;
    int tpl3MaxDirtyDuration = 2;
    // stress --vm 1000 --bytes 70K
    double tpl3DirtyRate = 3;
    int tpl4MemUsed = 4000;
    int tpl4MaxDirtySize = 5;
    int tpl4MaxDirtyDuration = 3;
    // idle vm
    double tpl4DirtyRate = 0;
    // New default model
    Model mo = new DefaultModel();
    Mapping ma = mo.getMapping();
    // Create online source nodes and offline destination nodes
    List<Node> srcNodes = new ArrayList<>();
    List<Node> dstNodes = new ArrayList<>();
    for (int i = 0; i < nbSrcNodes; i++) {
        srcNodes.add(mo.newNode());
        ma.addOnlineNode(srcNodes.get(i));
    }
    for (int i = 0; i < nbDstNodes; i++) {
        dstNodes.add(mo.newNode());
        ma.addOfflineNode(dstNodes.get(i));
    }
    // Set boot and shutdown time
    for (Node n : dstNodes) {
        mo.getAttributes().put(n, "boot", 120);
    /*~2 minutes to boot*/
    }
    for (Node n : srcNodes) {
        mo.getAttributes().put(n, "shutdown", 17);
    /*~30 seconds to shutdown*/
    }
    // Create running VMs on src nodes
    List<VM> vms = new ArrayList<>();
    VM v;
    for (int i = 0; i < nbSrcNodes; i++) {
        if (i % 2 == 0) {
            v = mo.newVM();
            vms.add(v);
            mo.getAttributes().put(v, "memUsed", tpl1MemUsed);
            mo.getAttributes().put(v, "coldDirtyRate", tpl1DirtyRate);
            mo.getAttributes().put(v, "hotDirtySize", tpl1MaxDirtySize);
            mo.getAttributes().put(v, "hotDirtyDuration", tpl1MaxDirtyDuration);
            ma.addRunningVM(v, srcNodes.get(i));
            v = mo.newVM();
            vms.add(v);
            mo.getAttributes().put(v, "memUsed", tpl2MemUsed);
            mo.getAttributes().put(v, "coldDirtyRate", tpl2DirtyRate);
            mo.getAttributes().put(v, "hotDirtySize", tpl2MaxDirtySize);
            mo.getAttributes().put(v, "hotDirtyDuration", tpl2MaxDirtyDuration);
            ma.addRunningVM(v, srcNodes.get(i));
        } else {
            v = mo.newVM();
            vms.add(v);
            mo.getAttributes().put(v, "memUsed", tpl3MemUsed);
            mo.getAttributes().put(v, "coldDirtyRate", tpl3DirtyRate);
            mo.getAttributes().put(v, "hotDirtySize", tpl3MaxDirtySize);
            mo.getAttributes().put(v, "hotDirtyDuration", tpl3MaxDirtyDuration);
            ma.addRunningVM(v, srcNodes.get(i));
            v = mo.newVM();
            vms.add(v);
            mo.getAttributes().put(v, "memUsed", tpl4MemUsed);
            mo.getAttributes().put(v, "coldDirtyRate", tpl4DirtyRate);
            mo.getAttributes().put(v, "hotDirtySize", tpl4MaxDirtySize);
            mo.getAttributes().put(v, "hotDirtyDuration", tpl4MaxDirtyDuration);
            ma.addRunningVM(v, srcNodes.get(i));
        }
    }
    // Add resource decorators
    ShareableResource rcMem = new ShareableResource("mem", 0, 0);
    ShareableResource rcCPU = new ShareableResource("cpu", 0, 0);
    for (Node n : srcNodes) {
        rcMem.setCapacity(n, memSrcNode);
        rcCPU.setCapacity(n, cpuSrcNode);
    }
    for (Node n : dstNodes) {
        rcMem.setCapacity(n, memDstNode);
        rcCPU.setCapacity(n, cpuDstNode);
    }
    for (VM vm : vms) {
        rcMem.setConsumption(vm, memVM);
        rcCPU.setConsumption(vm, cpuVM);
    }
    mo.attach(rcMem);
    mo.attach(rcCPU);
    // Add a NetworkView view
    Network net = new Network();
    Switch swSrcRack1 = net.newSwitch();
    Switch swSrcRack2 = net.newSwitch();
    Switch swSrcRack3 = net.newSwitch();
    Switch swSrcRack4 = net.newSwitch();
    Switch swSrcRack5 = net.newSwitch();
    Switch swSrcRack6 = net.newSwitch();
    Switch swSrcRack7 = net.newSwitch();
    Switch swSrcRack8 = net.newSwitch();
    Switch swDstRack1 = net.newSwitch();
    Switch swDstRack2 = net.newSwitch();
    Switch swDstRack3 = net.newSwitch();
    Switch swDstRack4 = net.newSwitch();
    Switch swMain = net.newSwitch();
    net.connect(1000, swSrcRack1, srcNodes.subList(0, nbNodesRack));
    net.connect(1000, swSrcRack2, srcNodes.subList(nbNodesRack, nbNodesRack * 2));
    net.connect(1000, swSrcRack3, srcNodes.subList(nbNodesRack * 2, nbNodesRack * 3));
    net.connect(1000, swSrcRack4, srcNodes.subList(nbNodesRack * 3, nbNodesRack * 4));
    net.connect(1000, swSrcRack5, srcNodes.subList(nbNodesRack * 4, nbNodesRack * 5));
    net.connect(1000, swSrcRack6, srcNodes.subList(nbNodesRack * 5, nbNodesRack * 6));
    net.connect(1000, swSrcRack7, srcNodes.subList(nbNodesRack * 6, nbNodesRack * 7));
    net.connect(1000, swSrcRack8, srcNodes.subList(nbNodesRack * 7, nbNodesRack * 8));
    net.connect(1000, swDstRack1, dstNodes.subList(0, nbNodesRack));
    net.connect(1000, swDstRack2, dstNodes.subList(nbNodesRack, nbNodesRack * 2));
    net.connect(1000, swDstRack3, dstNodes.subList(nbNodesRack * 2, nbNodesRack * 3));
    net.connect(1000, swDstRack4, dstNodes.subList(nbNodesRack * 3, nbNodesRack * 4));
    net.connect(40000, swMain, swSrcRack1, swSrcRack2, swSrcRack3, swSrcRack4, swSrcRack5, swSrcRack6, swSrcRack7, swSrcRack8, swDstRack1, swDstRack2, swDstRack3, swDstRack4);
    mo.attach(net);
    // net.generateDot(path + "topology.dot", false);
    // Set parameters
    DefaultParameters ps = new DefaultParameters();
    ps.setVerbosity(0);
    ps.setTimeLimit(60);
    // ps.setMaxEnd(600);
    ps.doOptimize(false);
    // Migrate all VMs to destination nodes
    List<SatConstraint> cstrs = new ArrayList<>();
    int vm_num = 0;
    for (int i = 0; i < nbDstNodes; i++) {
        cstrs.add(new Fence(vms.get(vm_num), Collections.singleton(dstNodes.get(i))));
        cstrs.add(new Fence(vms.get(vm_num + 1), Collections.singleton(dstNodes.get(i))));
        cstrs.add(new Fence(vms.get(nbVMs - 1 - vm_num), Collections.singleton(dstNodes.get(i))));
        cstrs.add(new Fence(vms.get(nbVMs - 2 - vm_num), Collections.singleton(dstNodes.get(i))));
        vm_num += 2;
    }
    // Shutdown source nodes
    cstrs.addAll(srcNodes.stream().map(Offline::new).collect(Collectors.toList()));
    // Set a custom objective
    DefaultChocoScheduler sc = new DefaultChocoScheduler(ps);
    Instance i = new Instance(mo, cstrs, new MinMTTRMig());
    ReconfigurationPlan p;
    try {
        p = sc.solve(i);
        Assert.assertNotNull(p);
    } catch (Exception e) {
        e.printStackTrace();
    }
    // finally {
    return sc.getStatistics();
// }
}

Example 2 with MinMTTRMig

use of org.btrplace.model.constraint.migration.MinMTTRMig in project scheduler by btrplace.

the class CDeadlineTest method testKo.

@Test
public void testKo() throws SchedulerException {
    // New default model
    Model mo = new DefaultModel();
    Mapping ma = mo.getMapping();
    // Create and boot 2 source nodes and 1 destination node
    Node srcNode1 = mo.newNode();
    Node srcNode2 = mo.newNode();
    Node dstNode = mo.newNode();
    ma.addOnlineNode(srcNode1);
    ma.addOnlineNode(srcNode2);
    ma.addOnlineNode(dstNode);
    // Attach a network view
    Network net = new Network();
    mo.attach(net);
    // Connect the nodes through a main non-blocking switch with 1 Gbit/s links
    Switch swMain = net.newSwitch();
    net.connect(1000, swMain, srcNode1, srcNode2);
    net.connect(1000, swMain, dstNode);
    // Create and host 1 VM per source node
    VM vm1 = mo.newVM();
    VM vm2 = mo.newVM();
    ma.addRunningVM(vm1, srcNode1);
    ma.addRunningVM(vm2, srcNode2);
    // Attach CPU and Mem resource views and assign nodes capacity and VMs consumption
    int mem_vm = 8;
    int cpu_vm = 4;
    int mem_src = 8;
    int cpu_src = 4;
    int mem_dst = 16;
    int cpu_dst = 8;
    ShareableResource rcMem = new ShareableResource("mem", 0, 0);
    ShareableResource rcCPU = new ShareableResource("cpu", 0, 0);
    mo.attach(rcMem);
    mo.attach(rcCPU);
    // VMs
    rcMem.setConsumption(vm1, mem_vm).setConsumption(vm2, mem_vm);
    rcCPU.setConsumption(vm1, cpu_vm).setConsumption(vm2, cpu_vm);
    // Nodes
    rcMem.setCapacity(srcNode1, mem_src).setCapacity(srcNode2, mem_src).setCapacity(dstNode, mem_dst);
    rcCPU.setCapacity(srcNode1, cpu_src).setCapacity(srcNode2, cpu_src).setCapacity(dstNode, cpu_dst);
    // Set VM attributes 'memory used', 'hot dirty page size', 'hot dirty page duration' and 'cold dirty pages rate'
    int vm_mu = 6000;
    int vm_mds = 46;
    int vm_mdd = 2;
    double vm_cdr = 23.6;
    // vm1 is an 'idle' VM (with no special memory activity) but still consumes 6 GiB of memory
    mo.getAttributes().put(vm1, "memUsed", vm_mu);
    // vm2 consumes 6 GiB memory and has a memory intensive workload equivalent to "stress --vm 1000 --bytes 50K"
    // VM with a workload
    mo.getAttributes().put(vm2, "memUsed", vm_mu);
    mo.getAttributes().put(vm2, "hotDirtySize", vm_mds);
    mo.getAttributes().put(vm2, "hotDirtyDuration", vm_mdd);
    mo.getAttributes().put(vm2, "coldDirtyRate", vm_cdr);
    // Create constraints
    List<SatConstraint> cstrs = new ArrayList<>();
    // Placement constraints, we want to shutdown the source nodes to force the migration to destination nodes
    cstrs.add(new Offline(srcNode1));
    cstrs.add(new Offline(srcNode2));
    // SET A TOO SHORT DEADLINE FOR THE MIGRATION OF VM2
    // 30s
    Deadline dead = new Deadline(vm2, "+00:00:30");
    cstrs.add(dead);
    // Try to solve it using the Min Max Time To Repair Migration scheduling oriented objective
    ReconfigurationPlan p = new DefaultChocoScheduler().solve(mo, cstrs, new MinMTTRMig());
    Assert.assertNull(p);
}

Example 3 with MinMTTRMig

use of org.btrplace.model.constraint.migration.MinMTTRMig in project scheduler by btrplace.

the class CDeadlineTest method testOk.

@Test
public void testOk() throws SchedulerException {
    // New default model
    Model mo = new DefaultModel();
    Mapping ma = mo.getMapping();
    // Create and boot 2 source nodes and 1 destination node
    Node srcNode1 = mo.newNode();
    Node srcNode2 = mo.newNode();
    Node dstNode = mo.newNode();
    ma.addOnlineNode(srcNode1);
    ma.addOnlineNode(srcNode2);
    ma.addOnlineNode(dstNode);
    // Attach a network view
    Network net = new Network();
    mo.attach(net);
    // Connect the nodes through a main non-blocking switch
    // The destination node have twice the bandwidth of source nodes
    Switch swMain = net.newSwitch();
    net.connect(1000, swMain, srcNode1, srcNode2);
    net.connect(2000, swMain, dstNode);
    // Create and host 1 VM per source node
    VM vm1 = mo.newVM();
    VM vm2 = mo.newVM();
    ma.addRunningVM(vm1, srcNode1);
    ma.addRunningVM(vm2, srcNode2);
    // Attach CPU and Mem resource views and assign nodes capacity and VMs consumption
    int mem_vm = 8;
    int cpu_vm = 4;
    int mem_src = 8;
    int cpu_src = 4;
    int mem_dst = 16;
    int cpu_dst = 8;
    ShareableResource rcMem = new ShareableResource("mem", 0, 0);
    ShareableResource rcCPU = new ShareableResource("cpu", 0, 0);
    mo.attach(rcMem);
    mo.attach(rcCPU);
    // VMs
    rcMem.setConsumption(vm1, mem_vm).setConsumption(vm2, mem_vm);
    rcCPU.setConsumption(vm1, cpu_vm).setConsumption(vm2, cpu_vm);
    // Nodes
    rcMem.setCapacity(srcNode1, mem_src).setCapacity(srcNode2, mem_src).setCapacity(dstNode, mem_dst);
    rcCPU.setCapacity(srcNode1, cpu_src).setCapacity(srcNode2, cpu_src).setCapacity(dstNode, cpu_dst);
    // Set VM attributes 'memory used', 'hot dirty page size', 'hot dirty page duration' and 'cold dirty pages rate'
    int vm_mu = 6000;
    int vm_mds = 46;
    int vm_mdd = 2;
    double vm_cdr = 23.6;
    // vm1 is an 'idle' VM (with no special memory activity) but still consumes 6 GiB of memory
    mo.getAttributes().put(vm1, "memUsed", vm_mu);
    // vm2 consumes 6 GiB memory and has a memory intensive workload equivalent to "stress --vm 1000 --bytes 50K"
    // VM with a workload
    mo.getAttributes().put(vm2, "memUsed", vm_mu);
    mo.getAttributes().put(vm2, "hotDirtySize", vm_mds);
    mo.getAttributes().put(vm2, "hotDirtyDuration", vm_mdd);
    mo.getAttributes().put(vm2, "coldDirtyRate", vm_cdr);
    // Create constraints
    List<SatConstraint> cstrs = new ArrayList<>();
    // Placement constraints, we want to shutdown the source nodes to force the migration to destination nodes
    cstrs.add(new Offline(srcNode1));
    cstrs.add(new Offline(srcNode2));
    // SET A RELATIVE DEADLINE FOR THE MIGRATION OF VM2
    // 90s
    Deadline dead = new Deadline(vm2, "+00:01:30");
    cstrs.add(dead);
    // Solve it using the Min Max Time To Repair Migration scheduling oriented objective
    ReconfigurationPlan p = new DefaultChocoScheduler().solve(mo, cstrs, new MinMTTRMig());
    // It works because 30s is enough to fully migrate vm2
    Assert.assertNotNull(p);
    // Check if the deadline is respected
    Action mig1 = p.getActions().stream().filter(s -> s instanceof MigrateVM && ((MigrateVM) s).getVM().equals(vm1)).findAny().get();
    Assert.assertTrue(mig1.getEnd() <= 90);
    // TODO: use methods on DeadlineChecker to verify that the action terminates at time ?
    Assert.assertTrue(dead.isSatisfied(p));
}

Example 4 with MinMTTRMig

use of org.btrplace.model.constraint.migration.MinMTTRMig in project scheduler by btrplace.

the class CPrecedenceTest method testOk.

@Test
public void testOk() throws SchedulerException {
    // New default model
    Model mo = new DefaultModel();
    Mapping ma = mo.getMapping();
    // Create and boot 2 source nodes and 1 destination node
    Node srcNode1 = mo.newNode();
    Node srcNode2 = mo.newNode();
    Node dstNode = mo.newNode();
    ma.addOnlineNode(srcNode1);
    ma.addOnlineNode(srcNode2);
    ma.addOnlineNode(dstNode);
    // Attach a network view
    Network net = new Network();
    mo.attach(net);
    // Connect the nodes through a main non-blocking switch
    // The destination node have twice the bandwidth of source nodes
    Switch swMain = net.newSwitch();
    net.connect(1000, swMain, srcNode1, srcNode2);
    net.connect(2000, swMain, dstNode);
    // Create and host 1 VM per source node
    VM vm1 = mo.newVM();
    VM vm2 = mo.newVM();
    ma.addRunningVM(vm1, srcNode1);
    ma.addRunningVM(vm2, srcNode2);
    // Attach CPU and Mem resource views and assign nodes capacity and VMs consumption
    int mem_vm = 8;
    int cpu_vm = 4;
    int mem_src = 8;
    int cpu_src = 4;
    int mem_dst = 16;
    int cpu_dst = 8;
    ShareableResource rcMem = new ShareableResource("mem", 0, 0);
    ShareableResource rcCPU = new ShareableResource("cpu", 0, 0);
    mo.attach(rcMem);
    mo.attach(rcCPU);
    // VMs
    rcMem.setConsumption(vm1, mem_vm).setConsumption(vm2, mem_vm);
    rcCPU.setConsumption(vm1, cpu_vm).setConsumption(vm2, cpu_vm);
    // Nodes
    rcMem.setCapacity(srcNode1, mem_src).setCapacity(srcNode2, mem_src).setCapacity(dstNode, mem_dst);
    rcCPU.setCapacity(srcNode1, cpu_src).setCapacity(srcNode2, cpu_src).setCapacity(dstNode, cpu_dst);
    // Set VM attributes 'memory used', 'hot dirty page size', 'hot dirty page duration' and 'cold dirty pages rate'
    int vm_mu = 6000;
    int vm_mds = 46;
    int vm_mdd = 2;
    double vm_cdr = 23.6;
    // vm1 is an 'idle' VM (with no special memory activity) but still consumes 6 GiB of memory
    mo.getAttributes().put(vm1, "memUsed", vm_mu);
    // vm2 consumes 6 GiB memory and has a memory intensive workload equivalent to "stress --vm 1000 --bytes 50K"
    // VM with a workload
    mo.getAttributes().put(vm2, "memUsed", vm_mu);
    mo.getAttributes().put(vm2, "hotDirtySize", vm_mds);
    mo.getAttributes().put(vm2, "hotDirtyDuration", vm_mdd);
    mo.getAttributes().put(vm2, "coldDirtyRate", vm_cdr);
    // Create constraints
    List<SatConstraint> cstrs = new ArrayList<>();
    // Placement constraints, we want to shutdown the source nodes to force the migration to destination nodes
    cstrs.add(new Offline(srcNode1));
    cstrs.add(new Offline(srcNode2));
    // MIGRATE VM2 BEFORE VM1
    Precedence prec = new Precedence(vm2, vm1);
    cstrs.add(prec);
    // Solve it using the Min Max Time To Repair Migration scheduling oriented objective
    ReconfigurationPlan p = new DefaultChocoScheduler().solve(mo, cstrs, new MinMTTRMig());
    Assert.assertNotNull(p);
    // Check if the precedence constraint is respected
    Action mig1 = p.getActions().stream().filter(s -> s instanceof MigrateVM && ((MigrateVM) s).getVM().equals(vm1)).findAny().get();
    Action mig2 = p.getActions().stream().filter(s -> s instanceof MigrateVM && ((MigrateVM) s).getVM().equals(vm2)).findAny().get();
    Assert.assertTrue(mig1.getStart() >= mig2.getEnd());
    // TODO: use methods on PrecedenceChecker to verify that the migrations are in the expected order ?
    Assert.assertTrue(prec.isSatisfied(p));
}

Example 5 with MinMTTRMig

use of org.btrplace.model.constraint.migration.MinMTTRMig in project scheduler by btrplace.

the class CSyncTest method testKo.

@Test
public void testKo() throws SchedulerException {
    // New default model
    Model mo = new DefaultModel();
    Mapping ma = mo.getMapping();
    // Create and boot 2 source nodes and 1 destination node
    Node srcNode1 = mo.newNode();
    Node srcNode2 = mo.newNode();
    Node dstNode = mo.newNode();
    ma.addOnlineNode(srcNode1);
    ma.addOnlineNode(srcNode2);
    ma.addOnlineNode(dstNode);
    // Attach a network view
    Network net = new Network();
    mo.attach(net);
    // Connect the nodes through a main non-blocking switch with 1 Gbit/s links
    Switch swMain = net.newSwitch();
    net.connect(1000, swMain, srcNode1, srcNode2);
    net.connect(1000, swMain, dstNode);
    // Create and host 1 VM per source node
    VM vm1 = mo.newVM();
    VM vm2 = mo.newVM();
    ma.addRunningVM(vm1, srcNode1);
    ma.addRunningVM(vm2, srcNode2);
    // Attach CPU and Mem resource views and assign nodes capacity and VMs consumption
    int mem_vm = 8;
    int cpu_vm = 4;
    int mem_src = 8;
    int cpu_src = 4;
    int mem_dst = 16;
    int cpu_dst = 8;
    ShareableResource rcMem = new ShareableResource("mem", 0, 0);
    ShareableResource rcCPU = new ShareableResource("cpu", 0, 0);
    mo.attach(rcMem);
    mo.attach(rcCPU);
    // VMs
    rcMem.setConsumption(vm1, mem_vm).setConsumption(vm2, mem_vm);
    rcCPU.setConsumption(vm1, cpu_vm).setConsumption(vm2, cpu_vm);
    // Nodes
    rcMem.setCapacity(srcNode1, mem_src).setCapacity(srcNode2, mem_src).setCapacity(dstNode, mem_dst);
    rcCPU.setCapacity(srcNode1, cpu_src).setCapacity(srcNode2, cpu_src).setCapacity(dstNode, cpu_dst);
    // Set VM attributes 'memory used', 'hot dirty page size', 'hot dirty page duration' and 'cold dirty pages rate'
    int vm_mu = 6000;
    int vm_mds = 46;
    int vm_mdd = 2;
    double vm_cdr = 23.6;
    // vm1 is an 'idle' VM (with no special memory activity) but still consumes 6 GiB of memory
    mo.getAttributes().put(vm1, "memUsed", vm_mu);
    // vm2 consumes 6 GiB memory and has a memory intensive workload equivalent to "stress --vm 1000 --bytes 50K"
    // VM with a workload
    mo.getAttributes().put(vm2, "memUsed", vm_mu);
    mo.getAttributes().put(vm2, "hotDirtySize", vm_mds);
    mo.getAttributes().put(vm2, "hotDirtyDuration", vm_mdd);
    mo.getAttributes().put(vm2, "coldDirtyRate", vm_cdr);
    // Create constraints
    List<SatConstraint> cstrs = new ArrayList<>();
    // Placement constraints, we want to shutdown the source nodes to force the migration to destination nodes
    cstrs.add(new Offline(srcNode1));
    cstrs.add(new Offline(srcNode2));
    // TRY TO SYNCHRONIZE THE TWO MIGRATIONS
    Sync sync = new Sync(vm1, vm2);
    cstrs.add(sync);
    // Solve it using the Min Max Time To Repair Migration scheduling oriented objective
    ChocoScheduler sched = new DefaultChocoScheduler();
    ReconfigurationPlan p = sched.solve(mo, cstrs, new MinMTTRMig());
    // Unable to sync two migrations on the same path !
    Assert.assertNull(p);
}