Fix followers not creating periodic launch

CHANGELOG.md

@@ -50,6 +50,8 @@ IMPROVEMENTS:
 
 BUG FIXES:
 
+ * core: Fix issue in which restoring periodic jobs could fail when a leader
+   election occurs [GH-3646]
  * core: Fixed an issue where the leader server could get into a state where it
    was no longer performing the periodic leader loop duties after a barrier
    timeout error [GH-3402]

nomad/fsm.go

@@ -351,21 +351,20 @@ func (n *nomadFSM) applyUpsertJob(buf []byte, index uint64) interface{} {
 	// We always add the job to the periodic dispatcher because there is the
 	// possibility that the periodic spec was removed and then we should stop
 	// tracking it.
-	added, err := n.periodicDispatcher.Add(req.Job)
-	if err != nil {
+	if err := n.periodicDispatcher.Add(req.Job); err != nil {
 		n.logger.Printf("[ERR] nomad.fsm: periodicDispatcher.Add failed: %v", err)
 		return err
 	}
 
 	// Create a watch set
 	ws := memdb.NewWatchSet()
 
-	// If it is periodic, record the time it was inserted. This is necessary for
-	// recovering during leader election. It is possible that from the time it
-	// is added to when it was suppose to launch, leader election occurs and the
-	// job was not launched. In this case, we use the insertion time to
-	// determine if a launch was missed.
-	if added {
+	// If it is an active periodic job, record the time it was inserted. This is
+	// necessary for recovering during leader election. It is possible that from
+	// the time it is added to when it was suppose to launch, leader election
+	// occurs and the job was not launched. In this case, we use the insertion
+	// time to determine if a launch was missed.
+	if req.Job.IsPeriodicActive() {
 		prevLaunch, err := n.state.PeriodicLaunchByID(ws, req.Namespace, req.Job.ID)
 		if err != nil {
 			n.logger.Printf("[ERR] nomad.fsm: PeriodicLaunchByID failed: %v", err)

nomad/fsm_test.go

@@ -331,6 +331,65 @@ func TestFSM_RegisterJob(t *testing.T) {
 	}
 }
 
+func TestFSM_RegisterPeriodicJob_NonLeader(t *testing.T) {
+	t.Parallel()
+	fsm := testFSM(t)
+
+	// Disable the dispatcher
+	fsm.periodicDispatcher.SetEnabled(false)
+
+	job := mock.PeriodicJob()
+	req := structs.JobRegisterRequest{
+		Job: job,
+		WriteRequest: structs.WriteRequest{
+			Namespace: job.Namespace,
+		},
+	}
+	buf, err := structs.Encode(structs.JobRegisterRequestType, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	resp := fsm.Apply(makeLog(buf))
+	if resp != nil {
+		t.Fatalf("resp: %v", resp)
+	}
+
+	// Verify we are registered
+	ws := memdb.NewWatchSet()
+	jobOut, err := fsm.State().JobByID(ws, req.Namespace, req.Job.ID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if jobOut == nil {
+		t.Fatalf("not found!")
+	}
+	if jobOut.CreateIndex != 1 {
+		t.Fatalf("bad index: %d", jobOut.CreateIndex)
+	}
+
+	// Verify it wasn't added to the periodic runner.
+	tuple := structs.NamespacedID{
+		ID:        job.ID,
+		Namespace: job.Namespace,
+	}
+	if _, ok := fsm.periodicDispatcher.tracked[tuple]; ok {
+		t.Fatal("job added to periodic runner")
+	}
+
+	// Verify the launch time was tracked.
+	launchOut, err := fsm.State().PeriodicLaunchByID(ws, req.Namespace, req.Job.ID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if launchOut == nil {
+		t.Fatalf("not found!")
+	}
+	if launchOut.Launch.IsZero() {
+		t.Fatalf("bad launch time: %v", launchOut.Launch)
+	}
+}
+
 func TestFSM_RegisterJob_BadNamespace(t *testing.T) {
 	t.Parallel()
 	fsm := testFSM(t)

nomad/leader.go

@@ -360,24 +360,26 @@ func (s *Server) restorePeriodicDispatcher() error {
 			continue
 		}
 
-		added, err := s.periodicDispatcher.Add(job)
-		if err != nil {
+		if err := s.periodicDispatcher.Add(job); err != nil {
 			return err
 		}
 
-		// We did not add the job to the tracker, this can be for a variety of
-		// reasons, but it means that we do not need to force run it.
-		if !added {
+		// We do not need to force run the job since it isn't active.
+		if !job.IsPeriodicActive() {
 			continue
 		}
 
 		// If the periodic job has never been launched before, launch will hold
 		// the time the periodic job was added. Otherwise it has the last launch
 		// time of the periodic job.
 		launch, err := s.fsm.State().PeriodicLaunchByID(ws, job.Namespace, job.ID)
-		if err != nil || launch == nil {
+		if err != nil {
 			return fmt.Errorf("failed to get periodic launch time: %v", err)
 		}
+		if launch == nil {
+			return fmt.Errorf("no recorded periodic launch time for job %q in namespace %q",
+				job.ID, job.Namespace)
+		}
 
 		// nextLaunch is the next launch that should occur.
 		nextLaunch := job.Periodic.Next(launch.Launch.In(job.Periodic.GetLocation()))

nomad/periodic.go

@@ -192,18 +192,18 @@ func (p *PeriodicDispatch) Tracked() []*structs.Job {
 // Add begins tracking of a periodic job. If it is already tracked, it acts as
 // an update to the jobs periodic spec. The method returns whether the job was
 // added and any error that may have occurred.
-func (p *PeriodicDispatch) Add(job *structs.Job) (added bool, err error) {
+func (p *PeriodicDispatch) Add(job *structs.Job) error {
 	p.l.Lock()
 	defer p.l.Unlock()
 
 	// Do nothing if not enabled
 	if !p.enabled {
-		return false, nil
+		return nil
 	}
 
 	// If we were tracking a job and it has been disabled, made non-periodic,
 	// stopped or is parameterized, remove it
-	disabled := !job.IsPeriodic() || !job.Periodic.Enabled || job.Stopped() || job.IsParameterized()
+	disabled := !job.IsPeriodicActive()
 
 	tuple := structs.NamespacedID{
 		ID:        job.ID,
@@ -216,20 +216,20 @@ func (p *PeriodicDispatch) Add(job *structs.Job) (added bool, err error) {
 		}
 
 		// If the job is disabled and we aren't tracking it, do nothing.
-		return false, nil
+		return nil
 	}
 
 	// Add or update the job.
 	p.tracked[tuple] = job
 	next := job.Periodic.Next(time.Now().In(job.Periodic.GetLocation()))
 	if tracked {
 		if err := p.heap.Update(job, next); err != nil {
-			return false, fmt.Errorf("failed to update job %q (%s) launch time: %v", job.ID, job.Namespace, err)
+			return fmt.Errorf("failed to update job %q (%s) launch time: %v", job.ID, job.Namespace, err)
 		}
 		p.logger.Printf("[DEBUG] nomad.periodic: updated periodic job %q (%s)", job.ID, job.Namespace)
 	} else {
 		if err := p.heap.Push(job, next); err != nil {
-			return false, fmt.Errorf("failed to add job %v: %v", job.ID, err)
+			return fmt.Errorf("failed to add job %v: %v", job.ID, err)
 		}
 		p.logger.Printf("[DEBUG] nomad.periodic: registered periodic job %q (%s)", job.ID, job.Namespace)
 	}
@@ -240,7 +240,7 @@ func (p *PeriodicDispatch) Add(job *structs.Job) (added bool, err error) {
 	default:
 	}
 
-	return true, nil
+	return nil
 }
 
 // Remove stops tracking the passed job. If the job is not tracked, it is a

nomad/periodic_endpoint_test.go

@@ -77,7 +77,7 @@ func TestPeriodicEndpoint_Force_ACL(t *testing.T) {
 	job := mock.PeriodicJob()
 	job.Periodic.ProhibitOverlap = true // Shouldn't affect anything.
 	assert.Nil(state.UpsertJob(100, job))
-	_, err := s1.periodicDispatcher.Add(job)
+	err := s1.periodicDispatcher.Add(job)
 	assert.Nil(err)
 
 	// Force launch it.