[processor/interval] Support Gauges and Summaries (open-telemetry#34805)

**Description:** Adds support for Gauges and Summaries 

**Link to tracking Issue:** open-telemetry#34803 

**Testing:** Unit tests were extended to cover the new behavior

**Documentation:** <Describe the documentation added.>

---------

Signed-off-by: Arthur Silva Sens <arthursens2005@gmail.com>

.chloggen/intervalprocessor_gauge_summary.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: processor/interval
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Support for gauge and summary metrics.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [34803]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: Only the last value of a gauge or summary metric is reported in the interval processor, instead of all values.
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

processor/intervalprocessor/README.md

@@ -19,19 +19,23 @@ The interval processor (`intervalprocessor`) aggregates metrics and periodically
 * Monotonically increasing, cumulative sums
 * Monotonically increasing, cumulative histograms
 * Monotonically increasing, cumulative exponential histograms
+* Gauges 
+* Summaries
 
 The following metric types will *not* be aggregated, and will instead be passed, unchanged, to the next component in the pipeline:
 
 * All delta metrics
 * Non-monotonically increasing sums
-* Gauges
-* Summaries
+
+> NOTE: Aggregating data over an interval is an inherently "lossy" process. For monotonically increasing, cumulative sums, histograms, and exponential histograms, you "lose" precision, but you don't lose overall data. But for non-monotonically increasing sums, gauges, and summaries, aggregation represents actual data loss. IE you could "lose" that a value increased and then decreased back to the original value. In most cases, this data "loss" is ok. However, if you would rather these values be passed through, and *not* aggregated, you can set that in the configuration
 
 ## Configuration
 
 The following settings can be optionally configured:
 
 * `interval`: The interval in which the processor should export the aggregated metrics. Default: 60s
+* `gauge_pass_through`: Whether gauges should pass through as they are to the next component or be aggregated. Default: false
+* `summary_pass_through`: Whether summaries should pass through as they are to the next component or be aggregated. Default: false
 
 ## Example of metric flows
 

processor/intervalprocessor/config.go

@@ -18,8 +18,14 @@ var _ component.Config = (*Config)(nil)
 
 // Config defines the configuration for the processor.
 type Config struct {
-	// Interval is the time
+	// Interval is the time interval at which the processor will aggregate metrics.
 	Interval time.Duration `mapstructure:"interval"`
+	// GaugePassThrough is a flag that determines whether gauge metrics should be passed through
+	// as they are or aggregated.
+	GaugePassThrough bool `mapstructure:"gauge_pass_through"`
+	// SummaryPassThrough is a flag that determines whether summary metrics should be passed through
+	// as they are or aggregated.
+	SummaryPassThrough bool `mapstructure:"summary_pass_through"`
 }
 
 // Validate checks whether the input configuration has all of the required fields for the processor.

processor/intervalprocessor/factory.go

@@ -25,7 +25,9 @@ func NewFactory() processor.Factory {
 
 func createDefaultConfig() component.Config {
 	return &Config{
-		Interval: 60 * time.Second,
+		Interval:           60 * time.Second,
+		GaugePassThrough:   false,
+		SummaryPassThrough: false,
 	}
 }
 

processor/intervalprocessor/internal/metrics/metrics.go

@@ -5,7 +5,6 @@ package metrics // import "github.com/open-telemetry/opentelemetry-collector-con
 
 import (
 	"go.opentelemetry.io/collector/pdata/pcommon"
-	"go.opentelemetry.io/collector/pdata/pmetric"
 )
 
 type DataPointSlice[DP DataPoint[DP]] interface {
@@ -15,8 +14,6 @@ type DataPointSlice[DP DataPoint[DP]] interface {
 }
 
 type DataPoint[Self any] interface {
-	pmetric.NumberDataPoint | pmetric.HistogramDataPoint | pmetric.ExponentialHistogramDataPoint
-
 	Timestamp() pcommon.Timestamp
 	Attributes() pcommon.Map
 	CopyTo(dest Self)

processor/intervalprocessor/processor.go

@@ -36,8 +36,11 @@ type Processor struct {
 	numberLookup       map[identity.Stream]pmetric.NumberDataPoint
 	histogramLookup    map[identity.Stream]pmetric.HistogramDataPoint
 	expHistogramLookup map[identity.Stream]pmetric.ExponentialHistogramDataPoint
+	summaryLookup      map[identity.Stream]pmetric.SummaryDataPoint
 
-	exportInterval time.Duration
+	exportInterval     time.Duration
+	gaugePassThrough   bool
+	summaryPassThrough bool
 
 	nextConsumer consumer.Metrics
 }
@@ -59,8 +62,11 @@ func newProcessor(config *Config, log *zap.Logger, nextConsumer consumer.Metrics
 		numberLookup:       map[identity.Stream]pmetric.NumberDataPoint{},
 		histogramLookup:    map[identity.Stream]pmetric.HistogramDataPoint{},
 		expHistogramLookup: map[identity.Stream]pmetric.ExponentialHistogramDataPoint{},
+		summaryLookup:      map[identity.Stream]pmetric.SummaryDataPoint{},
 
-		exportInterval: config.Interval,
+		exportInterval:     config.Interval,
+		gaugePassThrough:   config.GaugePassThrough,
+		summaryPassThrough: config.SummaryPassThrough,
 
 		nextConsumer: nextConsumer,
 	}
@@ -102,8 +108,22 @@ func (p *Processor) ConsumeMetrics(ctx context.Context, md pmetric.Metrics) erro
 		rm.ScopeMetrics().RemoveIf(func(sm pmetric.ScopeMetrics) bool {
 			sm.Metrics().RemoveIf(func(m pmetric.Metric) bool {
 				switch m.Type() {
-				case pmetric.MetricTypeGauge, pmetric.MetricTypeSummary:
-					return false
+				case pmetric.MetricTypeSummary:
+					if p.summaryPassThrough {
+						return false
+					}
+
+					mClone, metricID := p.getOrCloneMetric(rm, sm, m)
+					aggregateDataPoints(m.Summary().DataPoints(), mClone.Summary().DataPoints(), metricID, p.summaryLookup)
+					return true
+				case pmetric.MetricTypeGauge:
+					if p.gaugePassThrough {
+						return false
+					}
+
+					mClone, metricID := p.getOrCloneMetric(rm, sm, m)
+					aggregateDataPoints(m.Gauge().DataPoints(), mClone.Gauge().DataPoints(), metricID, p.numberLookup)
+					return true
 				case pmetric.MetricTypeSum:
 					// Check if we care about this value
 					sum := m.Sum()
@@ -202,6 +222,7 @@ func (p *Processor) exportMetrics() {
 		clear(p.numberLookup)
 		clear(p.histogramLookup)
 		clear(p.expHistogramLookup)
+		clear(p.summaryLookup)
 
 		return out
 	}()

processor/intervalprocessor/processor_test.go

@@ -21,26 +21,29 @@ import (
 func TestAggregation(t *testing.T) {
 	t.Parallel()
 
-	testCases := []string{
-		"basic_aggregation",
-		"non_monotonic_sums_are_passed_through",
-		"summaries_are_passed_through",
-		"histograms_are_aggregated",
-		"exp_histograms_are_aggregated",
-		"all_delta_metrics_are_passed_through",
+	testCases := []struct {
+		name        string
+		passThrough bool
+	}{
+		{name: "basic_aggregation"},
+		{name: "histograms_are_aggregated"},
+		{name: "exp_histograms_are_aggregated"},
+		{name: "gauges_are_aggregated"},
+		{name: "summaries_are_aggregated"},
+		{name: "all_delta_metrics_are_passed_through"},  // Deltas are passed through even when aggregation is enabled
+		{name: "non_monotonic_sums_are_passed_through"}, // Non-monotonic sums are passed through even when aggregation is enabled
+		{name: "gauges_are_passed_through", passThrough: true},
+		{name: "summaries_are_passed_through", passThrough: true},
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	config := &Config{Interval: time.Second}
-
+	var config *Config
 	for _, tc := range testCases {
-		testName := tc
-
-		t.Run(testName, func(t *testing.T) {
-			t.Parallel()
+		config = &Config{Interval: time.Second, GaugePassThrough: tc.passThrough, SummaryPassThrough: tc.passThrough}
 
+		t.Run(tc.name, func(t *testing.T) {
 			// next stores the results of the filter metric processor
 			next := &consumertest.MetricsSink{}
 
@@ -53,7 +56,7 @@ func TestAggregation(t *testing.T) {
 			)
 			require.NoError(t, err)
 
-			dir := filepath.Join("testdata", testName)
+			dir := filepath.Join("testdata", tc.name)
 
 			md, err := golden.ReadMetrics(filepath.Join(dir, "input.yaml"))
 			require.NoError(t, err)
@@ -75,6 +78,7 @@ func TestAggregation(t *testing.T) {
 			require.Empty(t, processor.numberLookup)
 			require.Empty(t, processor.histogramLookup)
 			require.Empty(t, processor.expHistogramLookup)
+			require.Empty(t, processor.summaryLookup)
 
 			// Exporting again should return nothing
 			processor.exportMetrics()

processor/intervalprocessor/testdata/gauges_are_aggregated/input.yaml

@@ -0,0 +1,40 @@
+resourceMetrics:
+  - schemaUrl: https://test-res-schema.com/schema
+    resource:
+      attributes:
+        - key: asdf
+          value:
+            stringValue: foo
+    scopeMetrics:
+      - schemaUrl: https://test-scope-schema.com/schema
+        scope:
+          name: MyTestInstrument
+          version: "1.2.3"
+          attributes:
+            - key: foo
+              value:
+                stringValue: bar
+        metrics:
+          - name: test.gauge
+            gauge:
+              aggregationTemporality: 2
+              dataPoints:
+                - timeUnixNano: 50
+                  asDouble: 345
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb
+                - timeUnixNano: 20
+                  asDouble: 258
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb
+                # For interval processor point of view, only the last datapoint should be passed through.
+                - timeUnixNano: 80
+                  asDouble: 178
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb                     

processor/intervalprocessor/testdata/gauges_are_aggregated/next.yaml

@@ -0,0 +1 @@
+resourceMetrics: []

processor/intervalprocessor/testdata/gauges_are_aggregated/output.yaml

@@ -0,0 +1,27 @@
+resourceMetrics:
+  - schemaUrl: https://test-res-schema.com/schema
+    resource:
+      attributes:
+        - key: asdf
+          value:
+            stringValue: foo
+    scopeMetrics:
+      - schemaUrl: https://test-scope-schema.com/schema
+        scope:
+          name: MyTestInstrument
+          version: "1.2.3"
+          attributes:
+            - key: foo
+              value:
+                stringValue: bar
+        metrics:
+          - name: test.gauge
+            gauge:
+              aggregationTemporality: 2
+              dataPoints:
+                - timeUnixNano: 80
+                  asDouble: 178
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb                      

processor/intervalprocessor/testdata/gauges_are_passed_through/input.yaml

@@ -36,4 +36,4 @@ resourceMetrics:
                   attributes:
                     - key: aaa
                       value:
-                        stringValue: bbb
+                        stringValue: bbb

processor/intervalprocessor/testdata/gauges_are_passed_through/next.yaml

@@ -36,4 +36,4 @@ resourceMetrics:
                   attributes:
                     - key: aaa
                       value:
-                        stringValue: bbb
+                        stringValue: bbb                      

processor/intervalprocessor/testdata/gauges_are_passed_through/output.yaml

@@ -1 +1 @@
-resourceMetrics: []
+resourceMetrics: []

processor/intervalprocessor/testdata/summaries_are_aggregated/input.yaml

@@ -0,0 +1,63 @@
+resourceMetrics:
+  - schemaUrl: https://test-res-schema.com/schema
+    resource:
+      attributes:
+        - key: asdf
+          value:
+            stringValue: foo
+    scopeMetrics:
+      - schemaUrl: https://test-scope-schema.com/schema
+        scope:
+          name: MyTestInstrument
+          version: "1.2.3"
+          attributes:
+            - key: foo
+              value:
+                stringValue: bar
+        metrics:
+          - name: summary.test
+            summary:
+              dataPoints:
+                - timeUnixNano: 50
+                  quantileValues:
+                    - quantile: 0.25
+                      value: 50
+                    - quantile: 0.5
+                      value: 20
+                    - quantile: 0.75
+                      value: 75
+                    - quantile: 0.95
+                      value: 10
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb
+                - timeUnixNano: 20
+                  quantileValues:
+                    - quantile: 0.25
+                      value: 40
+                    - quantile: 0.5
+                      value: 10
+                    - quantile: 0.75
+                      value: 60
+                    - quantile: 0.95
+                      value: 5
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb
+                # Only last summary should pass through
+                - timeUnixNano: 80
+                  quantileValues:
+                    - quantile: 0.25
+                      value: 80
+                    - quantile: 0.5
+                      value: 35
+                    - quantile: 0.75
+                      value: 90
+                    - quantile: 0.95
+                      value: 15
+                  attributes:
+                    - key: aaa
+                      value:
+                        stringValue: bbb

processor/intervalprocessor/testdata/summaries_are_aggregated/next.yaml

@@ -0,0 +1 @@
+resourceMetrics: []