system deployments: remove old rolling eval creation (#27007)

When using deployments, the deployment watcher emits all the evals we expect to
see to step through the deployment once each allocation becomes healthy for
`min_healthy_time`. But we left the old rolling-update eval code in place and
with the new job parsing of the `update` block that ends up emitting a eval
immediately with a zero wait time and we don't end up respecting the
`min_healthy_time`.

This is all driven from the deployment watcher now, so we can simply remove it
from the scheduler.

Author: tgross

scheduler/scheduler_system.go

@@ -52,7 +52,6 @@ type SystemScheduler struct {
 	deployment *structs.Deployment
 
 	limitReached bool
-	nextEval     *structs.Evaluation
 
 	failedTGAllocs  map[string]*structs.AllocMetric
 	queuedAllocs    map[string]int
@@ -100,7 +99,7 @@ func (s *SystemScheduler) Process(eval *structs.Evaluation) (err error) {
 	// Verify the evaluation trigger reason is understood
 	if !s.canHandle(eval.TriggeredBy) {
 		desc := fmt.Sprintf("scheduler cannot handle '%s' evaluation reason", eval.TriggeredBy)
-		return setStatus(s.logger, s.planner, s.eval, s.nextEval, nil,
+		return setStatus(s.logger, s.planner, s.eval, nil, nil,
 			s.failedTGAllocs, s.planAnnotations, structs.EvalStatusFailed, desc,
 			s.queuedAllocs, s.deployment.GetID())
 	}
@@ -114,15 +113,15 @@ func (s *SystemScheduler) Process(eval *structs.Evaluation) (err error) {
 	progress := func() bool { return progressMade(s.planResult) }
 	if err := retryMax(limit, s.process, progress); err != nil {
 		if statusErr, ok := err.(*SetStatusError); ok {
-			return setStatus(s.logger, s.planner, s.eval, s.nextEval, nil,
+			return setStatus(s.logger, s.planner, s.eval, nil, nil,
 				s.failedTGAllocs, s.planAnnotations, statusErr.EvalStatus, err.Error(),
 				s.queuedAllocs, s.deployment.GetID())
 		}
 		return err
 	}
 
 	// Update the status to complete
-	return setStatus(s.logger, s.planner, s.eval, s.nextEval, nil,
+	return setStatus(s.logger, s.planner, s.eval, nil, nil,
 		s.failedTGAllocs, s.planAnnotations, structs.EvalStatusComplete, "",
 		s.queuedAllocs, s.deployment.GetID())
 }
@@ -190,17 +189,6 @@ func (s *SystemScheduler) process() (bool, error) {
 		return true, nil
 	}
 
-	// If the limit of placements was reached we need to create an evaluation
-	// to pickup from here after the stagger period.
-	if s.limitReached && s.nextEval == nil {
-		s.nextEval = s.eval.NextRollingEval(s.job.Update.MinHealthyTime)
-		if err := s.planner.CreateEval(s.nextEval); err != nil {
-			s.logger.Error("failed to make next eval for rolling update", "error", err)
-			return false, err
-		}
-		s.logger.Debug("rolling update limit reached, next eval created", "next_eval_id", s.nextEval.ID)
-	}
-
 	// Submit the plan
 	if s.eval.AnnotatePlan {
 		s.plan.Annotations = s.planAnnotations

scheduler/scheduler_system_test.go

@@ -702,28 +702,6 @@ func TestSystemSched_JobModify_Rolling(t *testing.T) {
 	}
 
 	h.AssertEvalStatus(t, structs.EvalStatusComplete)
-
-	// Ensure a follow up eval was created
-	eval = h.Evals[0]
-	if eval.NextEval == "" {
-		t.Fatalf("missing next eval")
-	}
-
-	// Check for create
-	if len(h.CreateEvals) == 0 {
-		t.Fatalf("missing created eval")
-	}
-	create := h.CreateEvals[0]
-	if eval.NextEval != create.ID {
-		t.Fatalf("ID mismatch")
-	}
-	if create.PreviousEval != eval.ID {
-		t.Fatalf("missing previous eval")
-	}
-
-	if create.TriggeredBy != structs.EvalTriggerRollingUpdate {
-		t.Fatalf("bad: %#v", create)
-	}
 }
 
 func TestSystemSched_JobModify_InPlace(t *testing.T) {