Use approximate queue length for azure queue scaler (#4003)

CHANGELOG.md

@@ -78,6 +78,7 @@ Here is an overview of all new **experimental** features:
 
 - **General**: Fix regression in fallback mechanism ([#4249](https://github.com/kedacore/keda/issues/4249))
 - **General**: Prevent a panic that might occur while refreshing a scaler cache ([#4092](https://github.com/kedacore/keda/issues/4092))
+- **Azure Queue Scaler**: Fix azure queue length ([#4002](https://github.com/kedacore/keda/issues/4002))
 - **Azure Service Bus Scaler:** Use correct auth flows with pod identity ([#4026](https://github.com/kedacore/keda/issues/4026)|[#4123](https://github.com/kedacore/keda/issues/4123))
 - **Azure Service Bus Scaler:**: Improve way clients are created to reduce amount of ARM requests ([#4262](https://github.com/kedacore/keda/issues/4262))
 - **Cassandra Scaler**: Checking whether the port information is entered in the ClusterIPAddres is done correctly. ([#4110](https://github.com/kedacore/keda/issues/4110))

pkg/scalers/azure/azure_queue.go

@@ -25,11 +25,7 @@ import (
 	"github.com/kedacore/keda/v2/pkg/util"
 )
 
-const (
-	maxPeekMessages int32 = 32
-)
-
-// GetAzureQueueLength returns the length of a queue in int
+// GetAzureQueueLength returns the length of a queue in int, see https://learn.microsoft.com/en-us/azure/storage/queues/storage-dotnet-how-to-use-queues?tabs=dotnet#get-the-queue-length
 func GetAzureQueueLength(ctx context.Context, httpClient util.HTTPDoer, podIdentity kedav1alpha1.AuthPodIdentity, connectionString, queueName, accountName, endpointSuffix string) (int64, error) {
 	credential, endpoint, err := ParseAzureStorageQueueConnection(ctx, httpClient, podIdentity, connectionString, accountName, endpointSuffix)
 	if err != nil {
@@ -40,30 +36,10 @@ func GetAzureQueueLength(ctx context.Context, httpClient util.HTTPDoer, podIdent
 	serviceURL := azqueue.NewServiceURL(*endpoint, p)
 	queueURL := serviceURL.NewQueueURL(queueName)
 
-	visibleMessageCount, err := getVisibleCount(ctx, &queueURL, maxPeekMessages)
-	if err != nil {
-		return -1, err
-	}
-
-	// Queue has less messages than we allowed to peek for, so no need to get the approximation
-	if visibleMessageCount < int64(maxPeekMessages) {
-		return visibleMessageCount, nil
-	}
-
 	props, err := queueURL.GetProperties(ctx)
 	if err != nil {
 		return -1, err
 	}
 
 	return int64(props.ApproximateMessagesCount()), nil
 }
-
-func getVisibleCount(ctx context.Context, queueURL *azqueue.QueueURL, maxCount int32) (int64, error) {
-	messagesURL := queueURL.NewMessagesURL()
-	queue, err := messagesURL.Peek(ctx, maxCount)
-	if err != nil {
-		return 0, err
-	}
-	num := queue.NumMessages()
-	return int64(num), nil
-}