From 24b12b919168bb6c1e1b6cb8c1e631c160bdfa33 Mon Sep 17 00:00:00 2001
From: Marcin Wielgus <mwielgus@google.com>
Date: Fri, 26 Feb 2016 13:44:16 +0100
Subject: [PATCH] In HPA metric client make average from samples from the last
 1 minute

---
 .../podautoscaler/metrics/metrics_client.go   | 29 +++++++++++---
 .../metrics/metrics_client_test.go            | 38 +++++++++++++++++++
 2 files changed, 61 insertions(+), 6 deletions(-)

diff --git a/pkg/controller/podautoscaler/metrics/metrics_client.go b/pkg/controller/podautoscaler/metrics/metrics_client.go
index 89e18ab91fd..9b41f8737ab 100644
--- a/pkg/controller/podautoscaler/metrics/metrics_client.go
+++ b/pkg/controller/podautoscaler/metrics/metrics_client.go
@@ -74,7 +74,7 @@ type HeapsterMetricsClient struct {
 }
 
 var averageFunction = func(metrics heapster.MetricResultList) (intAndFloat, int, time.Time) {
-	sum, count, timestamp := calculateSumFromLatestSample(metrics)
+	sum, count, timestamp := calculateSumFromTimeSample(metrics, time.Minute)
 	result := intAndFloat{0, 0}
 	if count > 0 {
 		result.intValue = sum.intValue / int64(count)
@@ -218,7 +218,7 @@ func (h *HeapsterMetricsClient) getForPods(metricSpec metricDefinition, namespac
 	return &sum, timestamp, nil
 }
 
-func calculateSumFromLatestSample(metrics heapster.MetricResultList) (sum intAndFloat, count int, timestamp time.Time) {
+func calculateSumFromTimeSample(metrics heapster.MetricResultList, duration time.Duration) (sum intAndFloat, count int, timestamp time.Time) {
 	sum = intAndFloat{0, 0}
 	count = 0
 	timestamp = time.Time{}
@@ -236,12 +236,29 @@ func calculateSumFromLatestSample(metrics heapster.MetricResultList) (sum intAnd
 			if oldest == nil || newest.Timestamp.Before(*oldest) {
 				oldest = &newest.Timestamp
 			}
+			intervalSum := intAndFloat{0, 0}
+			intSumCount := 0
+			floatSumCount := 0
+			for _, metricPoint := range metrics.Metrics {
+				if metricPoint.Timestamp.Add(duration).After(newest.Timestamp) {
+					intervalSum.intValue += int64(metricPoint.Value)
+					intSumCount++
+					if metricPoint.FloatValue != nil {
+						intervalSum.floatValue += *metricPoint.FloatValue
+						floatSumCount++
+					}
+				}
+			}
 			if newest.FloatValue == nil {
-				sum.intValue += int64(newest.Value)
-				sum.floatValue += float64(newest.Value)
+				if intSumCount > 0 {
+					sum.intValue += int64(intervalSum.intValue / int64(intSumCount))
+					sum.floatValue += float64(intervalSum.intValue / int64(intSumCount))
+				}
 			} else {
-				sum.intValue += int64(*newest.FloatValue)
-				sum.floatValue += *newest.FloatValue
+				if floatSumCount > 0 {
+					sum.intValue += int64(intervalSum.floatValue / float64(floatSumCount))
+					sum.floatValue += intervalSum.floatValue / float64(floatSumCount)
+				}
 			}
 			count++
 		}
diff --git a/pkg/controller/podautoscaler/metrics/metrics_client_test.go b/pkg/controller/podautoscaler/metrics/metrics_client_test.go
index 9af3cecfbd5..38dfaabaf9a 100644
--- a/pkg/controller/podautoscaler/metrics/metrics_client_test.go
+++ b/pkg/controller/podautoscaler/metrics/metrics_client_test.go
@@ -413,4 +413,42 @@ func TestCPUEmptyMetricsForOnePod(t *testing.T) {
 	tc.runTest(t)
 }
 
+func TestAggregateSum(t *testing.T) {
+	//calculateSumFromTimeSample(metrics heapster.MetricResultList, duration time.Duration) (sum intAndFloat, count int, timestamp time.Time) {
+	now := time.Now()
+	result := heapster.MetricResultList{
+		Items: []heapster.MetricResult{
+			{
+				Metrics: []heapster.MetricPoint{
+					{now, 50, nil},
+					{now.Add(-15 * time.Second), 100, nil},
+					{now.Add(-60 * time.Second), 100000, nil}},
+				LatestTimestamp: now,
+			},
+		},
+	}
+	sum, cnt, _ := calculateSumFromTimeSample(result, time.Minute)
+	assert.Equal(t, int64(75), sum.intValue)
+	assert.InEpsilon(t, 75.0, sum.floatValue, 0.1)
+	assert.Equal(t, 1, cnt)
+}
+
+func TestAggregateSumSingle(t *testing.T) {
+	now := time.Now()
+	result := heapster.MetricResultList{
+		Items: []heapster.MetricResult{
+			{
+				Metrics: []heapster.MetricPoint{
+					{now, 50, nil},
+					{now.Add(-65 * time.Second), 100000, nil}},
+				LatestTimestamp: now,
+			},
+		},
+	}
+	sum, cnt, _ := calculateSumFromTimeSample(result, time.Minute)
+	assert.Equal(t, int64(50), sum.intValue)
+	assert.InEpsilon(t, 50.0, sum.floatValue, 0.1)
+	assert.Equal(t, 1, cnt)
+}
+
 // TODO: add proper tests for request