ebs br: make sure backup can be resumed even after being paused for a long time

pkg/backup/backupschedule/backup_schedule_manager.go

@@ -192,20 +192,18 @@ func getLastScheduledTime(bs *v1alpha1.BackupSchedule, nowFn nowFn) (*time.Time,
 		// If there is a bug somewhere, or incorrect clock
 		// on controller's server or apiservers (for setting creationTimestamp)
 		// then there could be so many missed start times (it could be off
-		// by decades or more), that it would eat up all the CPU and memory
-		// of this controller. In that case, we want to not try to list
-		// all the missed start times.
-		//
-		// I've somewhat arbitrarily picked 100, as more than 80,
-		// but less than "lots".
-		if len(scheduledTimes) > 100 {
+		// by decades or more). So, we need to set LastBackupTime to now() in order to let
+		// next reconcile succeed.
+		if len(scheduledTimes) > 1000 {
 			// We can't get the last backup schedule time
 			if bs.Status.LastBackupTime == nil && bs.Status.AllBackupCleanTime != nil {
 				// Recovery backup schedule from pause status, should refresh AllBackupCleanTime to avoid unschedulable problem
 				bs.Status.AllBackupCleanTime = &metav1.Time{Time: nowFn()}
 				return nil, controller.RequeueErrorf("recovery backup schedule %s/%s from pause status, refresh AllBackupCleanTime.", ns, bsName)
 			}
-			klog.Error("Too many missed start backup schedule time (> 100). Check the clock.")
+			klog.Warning("Too many missed start backup schedule time (> 1000). Fail current one.")
+			offset := sched.Next(t).Sub(t)
+			bs.Status.LastBackupTime = &metav1.Time{Time: time.Now().Add(-offset)}
 			return nil, nil
 		}
 	}

pkg/backup/backupschedule/backup_schedule_manager_test.go

@@ -176,10 +176,14 @@ func TestGetLastScheduledTime(t *testing.T) {
 	}
 
 	// test too many miss
-	bs.Status.LastBackupTime.Time = now.AddDate(-1000, 0, 0)
+	bs.Status.LastBackupTime.Time = now.AddDate(-10, 0, 0)
 	getTime, err = getLastScheduledTime(bs, time.Now)
 	g.Expect(err).Should(BeNil())
 	g.Expect(getTime).Should(BeNil())
+	// next reconcile should succeed
+	getTime, err = getLastScheduledTime(bs, time.Now)
+	g.Expect(err).Should(BeNil())
+	g.Expect(getTime).ShouldNot(BeNil())
 }
 
 func TestBuildBackup(t *testing.T) {

pkg/fedvolumebackup/backupschedule/backup_schedule_manager.go

@@ -117,20 +117,19 @@ func getLastScheduledTime(vbs *v1alpha1.VolumeBackupSchedule, nowFn nowFn) (*tim
 		// If there is a bug somewhere, or incorrect clock
 		// on controller's server or apiservers (for setting creationTimestamp)
 		// then there could be so many missed start times (it could be off
-		// by decades or more), that it would eat up all the CPU and memory
-		// of this controller. In that case, we want to not try to list
-		// all the missed start times.
-		//
-		// I've somewhat arbitrarily picked 100, as more than 80,
-		// but less than "lots".
-		if len(scheduledTimes) > 100 {
+		// by decades or more). So, we need to set LastBackupTime to now() in order to let
+		// next reconcile succeed.
+		if len(scheduledTimes) > 1000 {
 			// We can't get the last backup schedule time
 			if vbs.Status.LastBackupTime == nil && vbs.Status.AllBackupCleanTime != nil {
 				// Recovery backup schedule from pause status, should refresh AllBackupCleanTime to avoid unschedulable problem
 				vbs.Status.AllBackupCleanTime = &metav1.Time{Time: nowFn()}
 				return nil, controller.RequeueErrorf("recovery backup schedule %s/%s from pause status, refresh AllBackupCleanTime.", ns, bsName)
 			}
-			klog.Error("Too many missed start backup schedule time (> 100). Check the clock.")
+
+			klog.Warning("Too many missed start backup schedule time (> 1000). Fail current one.")
+			offset := sched.Next(t).Sub(t)
+			vbs.Status.LastBackupTime = &metav1.Time{Time: time.Now().Add(-offset)}
 			return nil, nil
 		}
 	}

pkg/fedvolumebackup/backupschedule/backup_schedule_manager_test.go

@@ -170,10 +170,14 @@ func TestGetLastScheduledTime(t *testing.T) {
 	}
 
 	// test too many miss
-	bs.Status.LastBackupTime.Time = now.AddDate(-1000, 0, 0)
+	bs.Status.LastBackupTime.Time = now.AddDate(-10, 0, 0)
 	getTime, err = getLastScheduledTime(bs, time.Now)
 	g.Expect(err).Should(BeNil())
 	g.Expect(getTime).Should(BeNil())
+	getTime, err = getLastScheduledTime(bs, time.Now)
+	// next reconcile should succeed
+	g.Expect(err).Should(BeNil())
+	g.Expect(getTime).ShouldNot(BeNil())
 }
 
 func TestBuildBackup(t *testing.T) {