MTV-1537 | Optimalise the plan scheduler (kubev2v#1088)

Issue: When we start the warm migration with VM which has a lot of disks
we wait for the whole VM to get migrated. We do not ignore the disks
that has been already migrated. This can cause that when we have 2 VMs
with 10 disks each and on each there is one larger disk the whole
scheduler will be halted untill they finish. So even if the left 9 disks
will be done no migration will be started.

Fix: Subtract the finished disks from the disk count.

Fixes: https://issues.redhat.com/browse/MTV-1537

Signed-off-by: Martin Necas <[email protected]>

pkg/controller/plan/scheduler/vsphere/scheduler.go

@@ -216,11 +216,27 @@ func (r *Scheduler) cost(vm *model.VM, vmStatus *plan.VMStatus) int {
 			return 0
 		default:
 			// CDI transfers the disks in parallel by different pods
-			return len(vm.Disks)
+			return len(vm.Disks) - r.finishedDisks(vmStatus)
 		}
 	}
 }
 
+// finishedDisks returns a number of the disks that have completed the disk transfer
+// This can reduce the migration time as VMs with one large disks and many small disks won't halt the scheduler
+func (r *Scheduler) finishedDisks(vmStatus *plan.VMStatus) int {
+	var resp = 0
+	for _, step := range vmStatus.Pipeline {
+		if step.Name == "DiskTransfer" {
+			for _, task := range step.Tasks {
+				if task.Phase == "Completed" {
+					resp += 1
+				}
+			}
+		}
+	}
+	return resp
+}
+
 // Return a map of all the VMs that could be scheduled
 // based on the available host capacities.
 func (r *Scheduler) schedulable() (schedulable map[string][]*pendingVM) {