fix: properly retrieve and close scalers cache (#4012)

Signed-off-by: Zbynek Roubalik <[email protected]> Signed-off-by: Zbynek Roubalik <[email protected]>
kedacore · Dec 15, 2022 · 06f6f7d · 06f6f7d
1 parent f4bee67
commit 06f6f7d
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Showing 3 changed files with 18 additions and 13 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -59,7 +59,7 @@ Here is an overview of all new **experimental** features:
 
 ### Fixes
 
-- **General**: TODO ([#TODO](https://github.com/kedacore/keda/issues/TODO))
+- **General**: Properly retrieve and close scalers cache ([#4011](https://github.com/kedacore/keda/issues/4011))
 
 ### Deprecations
 

diff --git a/pkg/scaling/cache/scalers_cache.go b/pkg/scaling/cache/scalers_cache.go
@@ -36,9 +36,10 @@ import (
 var log = logf.Log.WithName("scalers_cache")
 
 type ScalersCache struct {
-	ScaledObject *kedav1alpha1.ScaledObject
-	Scalers      []ScalerBuilder
-	Recorder     record.EventRecorder
+	ScaledObject             *kedav1alpha1.ScaledObject
+	Scalers                  []ScalerBuilder
+	ScalableObjectGeneration int64
+	Recorder                 record.EventRecorder
 }
 
 type ScalerBuilder struct {

diff --git a/pkg/scaling/scale_handler.go b/pkg/scaling/scale_handler.go
@@ -187,24 +187,24 @@ func (h *scaleHandler) GetScalersCache(ctx context.Context, scalableObject inter
 	key := withTriggers.GenerateIdentifier()
 	generation := withTriggers.Generation
 
-	return h.performGetScalersCache(ctx, key, scalableObject, generation, "", "", "")
+	return h.performGetScalersCache(ctx, key, scalableObject, &generation, "", "", "")
 }
 
 // getScalersCacheForScaledObject returns cache for input ScaledObject, referenced by name and namespace
 // we don't need to compare the Generation, because this method should be called only inside scale loop, where we have up to date object.
 func (h *scaleHandler) getScalersCacheForScaledObject(ctx context.Context, scaledObjectName, scaledObjectNamespace string) (*cache.ScalersCache, error) {
 	key := kedav1alpha1.GenerateIdentifier("ScaledObject", scaledObjectNamespace, scaledObjectName)
 
-	return h.performGetScalersCache(ctx, key, nil, -1, "ScaledObject", scaledObjectNamespace, scaledObjectName)
+	return h.performGetScalersCache(ctx, key, nil, nil, "ScaledObject", scaledObjectNamespace, scaledObjectName)
 }
 
 // performGetScalersCache returns cache for input scalableObject, it is common code used by GetScalersCache() and getScalersCacheForScaledObject() methods
-func (h *scaleHandler) performGetScalersCache(ctx context.Context, key string, scalableObject interface{}, scalableObjectGeneration int64, scalableObjectKind, scalableObjectNamespace, scalableObjectName string) (*cache.ScalersCache, error) {
+func (h *scaleHandler) performGetScalersCache(ctx context.Context, key string, scalableObject interface{}, scalableObjectGeneration *int64, scalableObjectKind, scalableObjectNamespace, scalableObjectName string) (*cache.ScalersCache, error) {
 	h.scalerCachesLock.RLock()
 	if cache, ok := h.scalerCaches[key]; ok {
 		// generation was specified -> let's include it in the check as well
-		if scalableObjectGeneration != -1 {
-			if scalableObject != nil && cache.ScaledObject != nil && cache.ScaledObject.Generation == scalableObjectGeneration {
+		if scalableObjectGeneration != nil {
+			if cache.ScalableObjectGeneration == *scalableObjectGeneration {
 				h.scalerCachesLock.RUnlock()
 				return cache, nil
 			}
@@ -219,10 +219,13 @@ func (h *scaleHandler) performGetScalersCache(ctx context.Context, key string, s
 	defer h.scalerCachesLock.Unlock()
 	if cache, ok := h.scalerCaches[key]; ok {
 		// generation was specified -> let's include it in the check as well
-		if scalableObjectGeneration != -1 {
-			if scalableObject != nil && cache.ScaledObject != nil && cache.ScaledObject.Generation == scalableObjectGeneration {
+		if scalableObjectGeneration != nil {
+			if cache.ScalableObjectGeneration == *scalableObjectGeneration {
 				return cache, nil
 			}
+			// object was found in cache, but the generation is not correct,
+			// let's close scalers in the cache and proceed further to recreate the cache
+			cache.Close(ctx)
 		} else {
 			return cache, nil
 		}
@@ -269,8 +272,9 @@ func (h *scaleHandler) performGetScalersCache(ctx context.Context, key string, s
 	}
 
 	newCache := &cache.ScalersCache{
-		Scalers:  scalers,
-		Recorder: h.recorder,
+		Scalers:                  scalers,
+		ScalableObjectGeneration: withTriggers.Generation,
+		Recorder:                 h.recorder,
 	}
 	switch obj := scalableObject.(type) {
 	case *kedav1alpha1.ScaledObject: