move the logic for measuring latency inside cache.GetMetricsForScaler()

move the logic for measuring latency inside cache.GetMetricsForScaler() Signed-off-by: kevin <tengkang@msn.com>
kedacore · Jan 6, 2023 · c62d21a · c62d21a
1 parent fad3925
commit c62d21a
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Showing 3 changed files with 14 additions and 12 deletions.
diff --git a/pkg/provider/provider.go b/pkg/provider/provider.go
@@ -166,7 +166,7 @@ func (p *KedaProvider) GetExternalMetric(ctx context.Context, namespace string,
 			}
 			// Filter only the desired metric
 			if strings.EqualFold(metricSpec.External.Metric.Name, info.Metric) {
-				metrics, err := cache.GetMetricsForScaler(ctx, scalerIndex, info.Metric)
+				metrics, _, err := cache.GetMetricsForScaler(ctx, scalerIndex, info.Metric)
 				metrics, err = fallback.GetMetricsWithFallback(ctx, p.client, logger, metrics, err, info.Metric, scaledObject, metricSpec)
 				if err != nil {
 					scalerError = true

diff --git a/pkg/scaling/cache/scalers_cache.go b/pkg/scaling/cache/scalers_cache.go
@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"math"
+	"time"
 
 	v2 "k8s.io/api/autoscaling/v2"
 	corev1 "k8s.io/api/core/v1"
@@ -69,24 +70,25 @@ func (c *ScalersCache) GetPushScalers() []scalers.PushScaler {
 	return result
 }
 
-// GetMetricsForScaler returns metric value for a scaler identified by the metric name
+// GetMetricsForScaler returns metric value and latency for a scaler identified by the metric name
 // and by the input index (from the list of scalers in this ScaledObject)
-func (c *ScalersCache) GetMetricsForScaler(ctx context.Context, index int, metricName string) ([]external_metrics.ExternalMetricValue, error) {
+func (c *ScalersCache) GetMetricsForScaler(ctx context.Context, index int, metricName string) ([]external_metrics.ExternalMetricValue, int64, error) {
 	if index < 0 || index >= len(c.Scalers) {
-		return nil, fmt.Errorf("scaler with id %d not found. Len = %d", index, len(c.Scalers))
+		return nil, -1, fmt.Errorf("scaler with id %d not found. Len = %d", index, len(c.Scalers))
 	}
+	startTime := time.Now()
 	m, _, err := c.Scalers[index].Scaler.GetMetricsAndActivity(ctx, metricName)
 	if err == nil {
-		return m, nil
+		return m, time.Since(startTime).Milliseconds(), nil
 	}
 
 	ns, err := c.refreshScaler(ctx, index)
 	if err != nil {
-		return nil, err
+		return nil, -1, err
 	}
-
+	startTime = time.Now()
 	m, _, err = ns.GetMetricsAndActivity(ctx, metricName)
-	return m, err
+	return m, time.Since(startTime).Milliseconds(), err
 }
 
 // GetScaledObjectState returns whether the input ScaledObject is active as a first parameters,

diff --git a/pkg/scaling/scale_handler.go b/pkg/scaling/scale_handler.go
@@ -440,10 +440,10 @@ func (h *scaleHandler) GetScaledObjectMetrics(ctx context.Context, scaledObjectN
 				}
 
 				if !metricsFoundInCache {
-					startTime := time.Now()
-					metrics, err = cache.GetMetricsForScaler(ctx, scalerIndex, metricName)
-					scalerLatency := time.Since(startTime).Milliseconds()
-					prommetrics.RecordScalerLatency(scaledObjectNamespace, scaledObject.Name, scalerName, scalerIndex, metricName, float64(scalerLatency))
+					metrics, latency, err := cache.GetMetricsForScaler(ctx, scalerIndex, metricName)
+					if latency != -1 {
+						prommetrics.RecordScalerLatency(scaledObjectNamespace, scaledObject.Name, scalerName, scalerIndex, metricName, float64(latency))
+					}
 					h.logger.V(1).Info("Getting metrics from scaler", "scaledObject.Namespace", scaledObjectNamespace, "scaledObject.Name", scaledObjectName, "scaler", scalerName, "metricName", metricSpec.External.Metric.Name, "metrics", metrics, "scalerError", err)
 				}
 				metrics, err = fallback.GetMetricsWithFallback(ctx, h.client, h.logger, metrics, err, metricName, scaledObject, metricSpec)