deploymentwatcher: fail early whenever possible (#17341)

Given a deployment that has a `progress_deadline`, if a task group runs
out of reschedule attempts, allow it to fail at this time instead of
waiting until the `progress_deadline` is reached.

Fixes: #17260

.changelog/17341.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+deploymentwatcher: Allow deployments to fail early when running out of reschedule attempts
+```

nomad/deploymentwatcher/deployment_watcher.go

@@ -615,12 +615,12 @@ func (w *deploymentWatcher) handleAllocUpdate(allocs []*structs.AllocListStub) (
 			continue
 		}
 
-		// Determine if the update block for this group is progress based
-		progressBased := dstate.ProgressDeadline != 0
+		// Check if we can already fail the deployment
+		failDeployment := w.shouldFailEarly(deployment, alloc, dstate)
 
 		// Check if the allocation has failed and we need to mark it for allow
 		// replacements
-		if progressBased && alloc.DeploymentStatus.IsUnhealthy() &&
+		if alloc.DeploymentStatus.IsUnhealthy() && !failDeployment &&
 			deployment.Active() && !alloc.DesiredTransition.ShouldReschedule() {
 			res.allowReplacements = append(res.allowReplacements, alloc.ID)
 			continue
@@ -631,19 +631,12 @@ func (w *deploymentWatcher) handleAllocUpdate(allocs []*structs.AllocListStub) (
 			res.createEval = true
 		}
 
-		// If the group is using a progress deadline, we don't have to do anything.
-		if progressBased {
-			continue
-		}
-
-		// Fail on the first bad allocation
-		if alloc.DeploymentStatus.IsUnhealthy() {
+		if failDeployment {
 			// Check if the group has autorevert set
 			if dstate.AutoRevert {
 				res.rollback = true
 			}
 
-			// Since we have an unhealthy allocation, fail the deployment
 			res.failDeployment = true
 		}
 
@@ -702,6 +695,31 @@ func (w *deploymentWatcher) shouldFail() (fail, rollback bool, err error) {
 	return fail, false, nil
 }
 
+func (w *deploymentWatcher) shouldFailEarly(deployment *structs.Deployment, alloc *structs.AllocListStub, dstate *structs.DeploymentState) bool {
+	if !alloc.DeploymentStatus.IsUnhealthy() {
+		return false
+	}
+
+	// Fail on the first unhealthy allocation if no progress deadline is specified.
+	if dstate.ProgressDeadline == 0 {
+		w.logger.Debug("failing deployment because an allocation failed and the deployment is not progress based", "alloc", alloc.ID)
+		return true
+	}
+
+	if deployment.Active() {
+		reschedulePolicy := w.j.LookupTaskGroup(alloc.TaskGroup).ReschedulePolicy
+		isRescheduleEligible := alloc.RescheduleEligible(reschedulePolicy, time.Now())
+		if !isRescheduleEligible {
+			// We have run out of reschedule attempts: do not wait for the progress deadline to expire because
+			// we know that we will not be able to try to get another allocation healthy
+			w.logger.Debug("failing deployment because an allocation has failed and the task group has run out of reschedule attempts", "alloc", alloc.ID)
+			return true
+		}
+	}
+
+	return false
+}
+
 // getDeploymentProgressCutoff returns the progress cutoff for the given
 // deployment
 func (w *deploymentWatcher) getDeploymentProgressCutoff(d *structs.Deployment) time.Time {

nomad/deploymentwatcher/deployments_watcher_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/hashicorp/nomad/nomad/mock"
 	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/hashicorp/nomad/testutil"
+	"github.com/shoenig/test/must"
 	"github.com/stretchr/testify/assert"
 	mocker "github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
@@ -1784,6 +1785,90 @@ func TestDeploymentWatcher_Watch_StartWithoutProgressDeadline(t *testing.T) {
 	})
 }
 
+// Test that we exit before hitting the Progress Deadline when we run out of reschedule attempts
+// for a failing deployment
+func TestDeploymentWatcher_Watch_FailEarly(t *testing.T) {
+	ci.Parallel(t)
+	w, m := testDeploymentWatcher(t, 1000.0, 1*time.Millisecond)
+
+	// Create a job, alloc, and a deployment
+	j := mock.Job()
+	j.TaskGroups[0].Update = structs.DefaultUpdateStrategy.Copy()
+	j.TaskGroups[0].Update.MaxParallel = 2
+	j.TaskGroups[0].Update.ProgressDeadline = 500 * time.Millisecond
+	// Allow only 1 allocation for that deployment
+	j.TaskGroups[0].ReschedulePolicy.Attempts = 0
+	j.TaskGroups[0].ReschedulePolicy.Unlimited = false
+	j.Stable = true
+	d := mock.Deployment()
+	d.JobID = j.ID
+	d.TaskGroups["web"].ProgressDeadline = 500 * time.Millisecond
+	d.TaskGroups["web"].RequireProgressBy = time.Now().Add(d.TaskGroups["web"].ProgressDeadline)
+	a := mock.Alloc()
+	now := time.Now()
+	a.CreateTime = now.UnixNano()
+	a.ModifyTime = now.UnixNano()
+	a.DeploymentID = d.ID
+	must.Nil(t, m.state.UpsertJob(structs.MsgTypeTestSetup, m.nextIndex(), nil, j), must.Sprint("UpsertJob"))
+	must.Nil(t, m.state.UpsertDeployment(m.nextIndex(), d), must.Sprint("UpsertDeployment"))
+	must.Nil(t, m.state.UpsertAllocs(structs.MsgTypeTestSetup, m.nextIndex(), []*structs.Allocation{a}), must.Sprint("UpsertAllocs"))
+
+	// require that we get a call to UpsertDeploymentStatusUpdate
+	c := &matchDeploymentStatusUpdateConfig{
+		DeploymentID:      d.ID,
+		Status:            structs.DeploymentStatusFailed,
+		StatusDescription: structs.DeploymentStatusDescriptionFailedAllocations,
+		Eval:              true,
+	}
+	m2 := matchDeploymentStatusUpdateRequest(c)
+	m.On("UpdateDeploymentStatus", mocker.MatchedBy(m2)).Return(nil)
+
+	w.SetEnabled(true, m.state)
+	testutil.WaitForResult(func() (bool, error) { return 1 == watchersCount(w), nil },
+		func(err error) { must.Eq(t, 1, watchersCount(w), must.Sprint("Should have 1 deployment")) })
+
+	// Update the alloc to be unhealthy
+	a2 := a.Copy()
+	a2.DeploymentStatus = &structs.AllocDeploymentStatus{
+		Healthy:   pointer.Of(false),
+		Timestamp: now,
+	}
+	must.Nil(t, m.state.UpdateAllocsFromClient(structs.MsgTypeTestSetup, m.nextIndex(), []*structs.Allocation{a2}))
+
+	// Wait for the deployment to be failed
+	testutil.WaitForResult(func() (bool, error) {
+		d, err := m.state.DeploymentByID(nil, d.ID)
+		if err != nil {
+			return false, err
+		}
+
+		if d.Status != structs.DeploymentStatusFailed {
+			return false, fmt.Errorf("bad status %q", d.Status)
+		}
+
+		return d.StatusDescription == structs.DeploymentStatusDescriptionFailedAllocations, fmt.Errorf("bad status description %q", d.StatusDescription)
+	}, func(err error) {
+		t.Fatal(err)
+	})
+
+	// require there are is only one evaluation
+	testutil.WaitForResult(func() (bool, error) {
+		ws := memdb.NewWatchSet()
+		evals, err := m.state.EvalsByJob(ws, j.Namespace, j.ID)
+		if err != nil {
+			return false, err
+		}
+
+		if l := len(evals); l != 1 {
+			return false, fmt.Errorf("Got %d evals; want 1", l)
+		}
+
+		return true, nil
+	}, func(err error) {
+		t.Fatal(err)
+	})
+}
+
 // Tests that the watcher fails rollback when the spec hasn't changed
 func TestDeploymentWatcher_RollbackFailed(t *testing.T) {
 	ci.Parallel(t)

nomad/structs/structs.go

@@ -10164,6 +10164,46 @@ func (rt *RescheduleTracker) Copy() *RescheduleTracker {
 	return nt
 }
 
+func (rt *RescheduleTracker) RescheduleEligible(reschedulePolicy *ReschedulePolicy, failTime time.Time) bool {
+	if reschedulePolicy == nil {
+		return false
+	}
+	attempts := reschedulePolicy.Attempts
+	enabled := attempts > 0 || reschedulePolicy.Unlimited
+	if !enabled {
+		return false
+	}
+	if reschedulePolicy.Unlimited {
+		return true
+	}
+	// Early return true if there are no attempts yet and the number of allowed attempts is > 0
+	if (rt == nil || len(rt.Events) == 0) && attempts > 0 {
+		return true
+	}
+	attempted, _ := rt.rescheduleInfo(reschedulePolicy, failTime)
+	return attempted < attempts
+}
+
+func (rt *RescheduleTracker) rescheduleInfo(reschedulePolicy *ReschedulePolicy, failTime time.Time) (int, int) {
+	if reschedulePolicy == nil {
+		return 0, 0
+	}
+	attempts := reschedulePolicy.Attempts
+	interval := reschedulePolicy.Interval
+
+	attempted := 0
+	if rt != nil && attempts > 0 {
+		for j := len(rt.Events) - 1; j >= 0; j-- {
+			lastAttempt := rt.Events[j].RescheduleTime
+			timeDiff := failTime.UTC().UnixNano() - lastAttempt
+			if timeDiff < interval.Nanoseconds() {
+				attempted += 1
+			}
+		}
+	}
+	return attempted, attempts
+}
+
 // RescheduleEvent is used to keep track of previous attempts at rescheduling an allocation
 type RescheduleEvent struct {
 	// RescheduleTime is the timestamp of a reschedule attempt
@@ -10598,47 +10638,11 @@ func (a *Allocation) ShouldReschedule(reschedulePolicy *ReschedulePolicy, failTi
 // RescheduleEligible returns if the allocation is eligible to be rescheduled according
 // to its ReschedulePolicy and the current state of its reschedule trackers
 func (a *Allocation) RescheduleEligible(reschedulePolicy *ReschedulePolicy, failTime time.Time) bool {
-	if reschedulePolicy == nil {
-		return false
-	}
-	attempts := reschedulePolicy.Attempts
-	enabled := attempts > 0 || reschedulePolicy.Unlimited
-	if !enabled {
-		return false
-	}
-	if reschedulePolicy.Unlimited {
-		return true
-	}
-	// Early return true if there are no attempts yet and the number of allowed attempts is > 0
-	if (a.RescheduleTracker == nil || len(a.RescheduleTracker.Events) == 0) && attempts > 0 {
-		return true
-	}
-	attempted, _ := a.rescheduleInfo(reschedulePolicy, failTime)
-	return attempted < attempts
-}
-
-func (a *Allocation) rescheduleInfo(reschedulePolicy *ReschedulePolicy, failTime time.Time) (int, int) {
-	if reschedulePolicy == nil {
-		return 0, 0
-	}
-	attempts := reschedulePolicy.Attempts
-	interval := reschedulePolicy.Interval
-
-	attempted := 0
-	if a.RescheduleTracker != nil && attempts > 0 {
-		for j := len(a.RescheduleTracker.Events) - 1; j >= 0; j-- {
-			lastAttempt := a.RescheduleTracker.Events[j].RescheduleTime
-			timeDiff := failTime.UTC().UnixNano() - lastAttempt
-			if timeDiff < interval.Nanoseconds() {
-				attempted += 1
-			}
-		}
-	}
-	return attempted, attempts
+	return a.RescheduleTracker.RescheduleEligible(reschedulePolicy, failTime)
 }
 
 func (a *Allocation) RescheduleInfo() (int, int) {
-	return a.rescheduleInfo(a.ReschedulePolicy(), a.LastEventTime())
+	return a.RescheduleTracker.rescheduleInfo(a.ReschedulePolicy(), a.LastEventTime())
 }
 
 // LastEventTime is the time of the last task event in the allocation.
@@ -10696,7 +10700,7 @@ func (a *Allocation) nextRescheduleTime(failTime time.Time, reschedulePolicy *Re
 	rescheduleEligible := reschedulePolicy.Unlimited || (reschedulePolicy.Attempts > 0 && a.RescheduleTracker == nil)
 	if reschedulePolicy.Attempts > 0 && a.RescheduleTracker != nil && a.RescheduleTracker.Events != nil {
 		// Check for eligibility based on the interval if max attempts is set
-		attempted, attempts := a.rescheduleInfo(reschedulePolicy, failTime)
+		attempted, attempts := a.RescheduleTracker.rescheduleInfo(reschedulePolicy, failTime)
 		rescheduleEligible = attempted < attempts && nextDelay < reschedulePolicy.Interval
 	}
 	return nextRescheduleTime, rescheduleEligible
@@ -11174,6 +11178,12 @@ func (a *AllocListStub) SetEventDisplayMessages() {
 	setDisplayMsg(a.TaskStates)
 }
 
+// RescheduleEligible returns if the allocation is eligible to be rescheduled according
+// to its ReschedulePolicy and the current state of its reschedule trackers
+func (a *AllocListStub) RescheduleEligible(reschedulePolicy *ReschedulePolicy, failTime time.Time) bool {
+	return a.RescheduleTracker.RescheduleEligible(reschedulePolicy, failTime)
+}
+
 func setDisplayMsg(taskStates map[string]*TaskState) {
 	for _, taskState := range taskStates {
 		for _, event := range taskState.Events {