[BUG-5656] Annotate Jobs with parent ScaledJob generation

CHANGELOG.md

@@ -72,6 +72,7 @@ Here is an overview of all new **experimental** features:
 
 ### Improvements
 
+- **General**: Do not delete running Jobs on KEDA restart ([#5656](https://github.com/kedacore/keda/issues/5656))
 - **Cassandra Scaler**: Add TLS support for cassandra scaler ([#5802](https://github.com/kedacore/keda/issues/5802))
 - **GCP Scalers**: Added custom time horizon in GCP scalers ([#5778](https://github.com/kedacore/keda/issues/5778))
 - **GitHub Scaler**: Fixed pagination, fetching repository list ([#5738](https://github.com/kedacore/keda/issues/5738))

controllers/keda/scaledjob_controller.go

@@ -279,22 +279,36 @@ func (r *ScaledJobReconciler) deletePreviousVersionScaleJobs(ctx context.Context
 			return "Cannot get list of Jobs owned by this scaledJob", err
 		}
 
-		if len(jobs.Items) > 0 {
-			logger.Info("RolloutStrategy: immediate, Deleting jobs owned by the previous version of the scaledJob", "numJobsToDelete", len(jobs.Items))
+		jobIndexes := make([]int, 0, len(jobs.Items))
+		scaledJobGeneration := strconv.FormatInt(scaledJob.Generation, 10)
+		for i, job := range jobs.Items {
+			if jobGen, ok := job.Annotations["scaledjob.keda.sh/generation"]; !ok {
+				// delete Jobs that don't have the generation annotation
+				jobIndexes = append(jobIndexes, i)
+			} else if jobGen != scaledJobGeneration {
+				// delete Jobs that have a different generation annotation
+				jobIndexes = append(jobIndexes, i)
+			}
 		}
-		for _, job := range jobs.Items {
-			job := job
 
-			propagationPolicy := metav1.DeletePropagationBackground
-			if scaledJob.Spec.Rollout.PropagationPolicy == "foreground" {
-				propagationPolicy = metav1.DeletePropagationForeground
-			}
-			err = r.Client.Delete(ctx, &job, client.PropagationPolicy(propagationPolicy))
-			if err != nil {
-				return "Not able to delete job: " + job.Name, err
+		if len(jobIndexes) == 0 {
+			logger.Info("RolloutStrategy: immediate, No jobs owned by the previous version of the scaledJob")
+		} else {
+			logger.Info("RolloutStrategy: immediate, Deleting jobs owned by the previous version of the scaledJob", "numJobsToDelete", len(jobIndexes))
+			for _, index := range jobIndexes {
+				job := jobs.Items[index]
+
+				propagationPolicy := metav1.DeletePropagationBackground
+				if scaledJob.Spec.Rollout.PropagationPolicy == "foreground" {
+					propagationPolicy = metav1.DeletePropagationForeground
+				}
+				err = r.Client.Delete(ctx, &job, client.PropagationPolicy(propagationPolicy))
+				if err != nil {
+					return "Not able to delete job: " + job.Name, err
+				}
 			}
+			return fmt.Sprintf("RolloutStrategy: immediate, deleted jobs owned by the previous version of the scaleJob: %d jobs deleted", len(jobIndexes)), nil
 		}
-		return fmt.Sprintf("RolloutStrategy: immediate, deleted jobs owned by the previous version of the scaleJob: %d jobs deleted", len(jobs.Items)), nil
 	}
 	return fmt.Sprintf("RolloutStrategy: %s", scaledJob.Spec.RolloutStrategy), nil
 }

pkg/scaling/executor/scale_jobs.go

@@ -101,6 +101,10 @@ func (e *scaleExecutor) getScalingDecision(scaledJob *kedav1alpha1.ScaledJob, ru
 }
 
 func (e *scaleExecutor) createJobs(ctx context.Context, logger logr.Logger, scaledJob *kedav1alpha1.ScaledJob, scaleTo int64, maxScale int64) {
+	if maxScale <= 0 {
+		logger.Info("No need to create jobs - all requested jobs already exist", "jobs", maxScale)
+		return
+	}
 	logger.Info("Creating jobs", "Effective number of max jobs", maxScale)
 	if scaleTo > maxScale {
 		scaleTo = maxScale
@@ -137,14 +141,21 @@ func (e *scaleExecutor) generateJobs(logger logr.Logger, scaledJob *kedav1alpha1
 		labels[key] = value
 	}
 
+	annotations := map[string]string{
+		"scaledjob.keda.sh/generation": strconv.FormatInt(scaledJob.Generation, 10),
+	}
+	for key, value := range scaledJob.ObjectMeta.Annotations {
+		annotations[key] = value
+	}
+
 	jobs := make([]*batchv1.Job, int(scaleTo))
 	for i := 0; i < int(scaleTo); i++ {
 		job := &batchv1.Job{
 			ObjectMeta: metav1.ObjectMeta{
 				GenerateName: scaledJob.GetName() + "-",
 				Namespace:    scaledJob.GetNamespace(),
 				Labels:       labels,
-				Annotations:  scaledJob.ObjectMeta.Annotations,
+				Annotations:  annotations,
 			},
 			Spec: *scaledJob.Spec.JobTargetRef.DeepCopy(),
 		}

pkg/scaling/executor/scale_jobs_test.go

@@ -316,8 +316,11 @@ func TestCreateJobs(t *testing.T) {
 
 func TestGenerateJobs(t *testing.T) {
 	var (
-		expectedAnnotations = map[string]string{"test": "test"}
-		expectedLabels      = map[string]string{
+		expectedAnnotations = map[string]string{
+			"test":                         "test",
+			"scaledjob.keda.sh/generation": "0",
+		}
+		expectedLabels = map[string]string{
 			"app.kubernetes.io/managed-by": "keda-operator",
 			"app.kubernetes.io/name":       "test",
 			"app.kubernetes.io/part-of":    "test",