Stop before trying to place

nomad/structs/structs.go

@@ -2981,6 +2981,8 @@ func (t *Task) Copy() *Task {
 
 	if i, err := copystructure.Copy(nt.Config); err != nil {
 		nt.Config = i.(map[string]interface{})
+	} else {
+		panic(err.Error())
 	}
 
 	if t.Templates != nil {

scheduler/generic_sched.go

@@ -438,6 +438,9 @@ func (s *GenericScheduler) computeJobAllocs() error {
 	for _, place := range results.place {
 		s.queuedAllocs[place.taskGroup.Name] += 1
 	}
+	for _, destructive := range results.destructiveUpdate {
+		s.queuedAllocs[destructive.placeTaskGroup.Name] += 1
+	}
 
 	// Compute the placements
 	place := make([]placementResult, 0, len(results.place)+len(results.destructiveUpdate))
@@ -482,6 +485,15 @@ func (s *GenericScheduler) computePlacements(place []placementResult) error {
 			return err
 		}
 
+		// Check if we should stop the previous allocation upon successful
+		// placement of its replacement. This allow atomic placements/stops. We
+		// stop the allocation before trying to find a replacement because this
+		// frees the resources currently used by the previous allocation.
+		stopPrevAlloc, stopPrevAllocDesc := missing.StopPreviousAlloc()
+		if stopPrevAlloc {
+			s.plan.AppendUpdate(missing.PreviousAllocation(), structs.AllocDesiredStatusStop, stopPrevAllocDesc, "")
+		}
+
 		// Attempt to match the task group
 		var option *RankedNode
 		if preferredNode != nil {
@@ -531,19 +543,20 @@ func (s *GenericScheduler) computePlacements(place []placementResult) error {
 			// Track the placement
 			s.plan.AppendAlloc(alloc)
 
-			// Since we have placed check to see if we should stop any previous
-			// allocation
-			if stop, desc := missing.StopPreviousAlloc(); stop {
-				s.plan.AppendUpdate(missing.PreviousAllocation(), structs.AllocDesiredStatusStop, desc, "")
-			}
-
 		} else {
 			// Lazy initialize the failed map
 			if s.failedTGAllocs == nil {
 				s.failedTGAllocs = make(map[string]*structs.AllocMetric)
 			}
 
+			// Track the fact that we didn't find a placement
 			s.failedTGAllocs[tg.Name] = s.ctx.Metrics()
+
+			// If we weren't able to find a replacement for the allocation, back
+			// out the fact that we asked to stop the allocation.
+			if stopPrevAlloc {
+				s.plan.PopUpdate(missing.PreviousAllocation())
+			}
 		}
 	}
 

scheduler/generic_sched_test.go

@@ -1481,6 +1481,110 @@ func TestServiceSched_JobModify_Rolling(t *testing.T) {
 	}
 }
 
+func TestJob_CanCopy(t *testing.T) {
+	job := mock.Job()
+	job.Copy()
+}
+
+// This tests that the old allocation is stopped before placing.
+func TestServiceSched_JobModify_Rolling_FullNode(t *testing.T) {
+	h := NewHarness(t)
+
+	// Create a node
+	node := mock.Node()
+	noErr(t, h.State.UpsertNode(h.NextIndex(), node))
+
+	resourceAsk := node.Resources.Copy()
+	resourceAsk.CPU -= node.Reserved.CPU
+	resourceAsk.MemoryMB -= node.Reserved.MemoryMB
+	resourceAsk.DiskMB -= node.Reserved.DiskMB
+	resourceAsk.Networks = nil
+
+	// Generate a fake job with one alloc that consumes the whole node
+	job := mock.Job()
+	job.TaskGroups[0].Count = 1
+	job.TaskGroups[0].Tasks[0].Resources = resourceAsk
+	noErr(t, h.State.UpsertJob(h.NextIndex(), job))
+
+	alloc := mock.Alloc()
+	alloc.Resources = resourceAsk
+	alloc.Job = job
+	alloc.JobID = job.ID
+	alloc.NodeID = node.ID
+	alloc.Name = "my-job.web[0]"
+	noErr(t, h.State.UpsertAllocs(h.NextIndex(), []*structs.Allocation{alloc}))
+
+	// Update the job
+	job2 := job.Copy()
+	job2.TaskGroups[0].Update = &structs.UpdateStrategy{
+		MaxParallel:     1,
+		HealthCheck:     structs.UpdateStrategyHealthCheck_Checks,
+		MinHealthyTime:  10 * time.Second,
+		HealthyDeadline: 10 * time.Minute,
+	}
+
+	// Update the task, such that it cannot be done in-place
+	job2.TaskGroups[0].Tasks[0].Config["command"] = "/bin/other"
+	noErr(t, h.State.UpsertJob(h.NextIndex(), job2))
+
+	// Create a mock evaluation to deal with drain
+	eval := &structs.Evaluation{
+		ID:          structs.GenerateUUID(),
+		Priority:    50,
+		TriggeredBy: structs.EvalTriggerJobRegister,
+		JobID:       job.ID,
+	}
+
+	// Process the evaluation
+	err := h.Process(NewServiceScheduler, eval)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Ensure a single plan
+	if len(h.Plans) != 1 {
+		t.Fatalf("bad: %#v", h.Plans)
+	}
+	plan := h.Plans[0]
+
+	// Ensure the plan evicted only MaxParallel
+	var update []*structs.Allocation
+	for _, updateList := range plan.NodeUpdate {
+		update = append(update, updateList...)
+	}
+	if len(update) != 1 {
+		t.Fatalf("bad: got %d; want %d: %#v", len(update), 1, plan)
+	}
+
+	// Ensure the plan allocated
+	var planned []*structs.Allocation
+	for _, allocList := range plan.NodeAllocation {
+		planned = append(planned, allocList...)
+	}
+	if len(planned) != 1 {
+		t.Fatalf("bad: %#v", plan)
+	}
+
+	h.AssertEvalStatus(t, structs.EvalStatusComplete)
+
+	// Check that the deployment id is attached to the eval
+	if h.Evals[0].DeploymentID == "" {
+		t.Fatalf("Eval not annotated with deployment id")
+	}
+
+	// Ensure a deployment was created
+	if plan.Deployment == nil {
+		t.Fatalf("bad: %#v", plan)
+	}
+	state, ok := plan.Deployment.TaskGroups[job.TaskGroups[0].Name]
+	if !ok {
+		t.Fatalf("bad: %#v", plan)
+	}
+	if state.DesiredTotal != 1 && state.DesiredCanaries != 0 {
+		t.Fatalf("bad: %#v", state)
+	}
+}
+
 func TestServiceSched_JobModify_Canaries(t *testing.T) {
 	h := NewHarness(t)
 

scheduler/util.go

@@ -698,7 +698,10 @@ func desiredUpdates(diff *diffResult, inplaceUpdates,
 // adjustQueuedAllocations decrements the number of allocations pending per task
 // group based on the number of allocations successfully placed
 func adjustQueuedAllocations(logger *log.Logger, result *structs.PlanResult, queuedAllocs map[string]int) {
-	if result != nil {
+	if result == nil {
+		return
+	}
+
 	for _, allocations := range result.NodeAllocation {
 		for _, allocation := range allocations {
 			// Ensure that the allocation is newly created. We check that
@@ -719,7 +722,6 @@ func adjustQueuedAllocations(logger *log.Logger, result *structs.PlanResult, que
 			}
 		}
 	}
-	}
 }
 
 // updateNonTerminalAllocsToLost updates the allocations which are in pending/running state on tainted node