[service/internal/graph] Measure telemetry as it is passed between pipeline components

.chloggen/pipeline-component-metrics.yaml

@@ -0,0 +1,32 @@
+# 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. otlpreceiver)
+component: service
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add item count metrics defined in Pipeline Component Telemetry RFC
+
+# One or more tracking issues or pull requests related to the change
+issues: [12812]
+
+# (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: |
+  See [Pipeline Component Telemetry RFC](https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/rfcs/component-universal-telemetry.md) for more details:
+    - `otelcol.receiver.produced.items`
+    - `otelcol.processor.consumed.items`
+    - `otelcol.processor.produced.items`
+    - `otelcol.connector.consumed.items`
+    - `otelcol.connector.produced.items`
+    - `otelcol.exporter.consumed.items`
+
+# 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: []

cmd/mdatagen/internal/metric.go

@@ -59,6 +59,9 @@ type Metric struct {
 
 	// Attributes is the list of attributes that the metric emits.
 	Attributes []AttributeName `mapstructure:"attributes"`
+
+	// Override the default prefix for the metric name.
+	Prefix string `mapstructure:"prefix"`
 }
 
 type Stability struct {

cmd/mdatagen/internal/templates/documentation.md.tmpl

@@ -38,7 +38,7 @@
 {{- $metricName := . }}
 {{- $metric := $metricName | telemetryInfo -}}
 
-### otelcol_{{ $metricName }}
+### {{ if $metric.Prefix -}}{{ $metric.Prefix }}{{- else -}}otelcol_{{- end -}}{{ $metricName }}
 
 {{ $metric.Description }}{{ $metric.Stability }}
 

cmd/mdatagen/internal/templates/telemetry.go.tmpl

@@ -136,7 +136,11 @@ func NewTelemetryBuilder(settings component.TelemetrySettings, options ...Teleme
 
     {{- range $name, $metric := .Telemetry.Metrics }}
     builder.{{ $name.Render }}, err = builder.meter.{{ $metric.Data.Instrument }}(
+        {{ if $metric.Prefix -}}
+        "{{ $metric.Prefix }}{{ $name }}",
+        {{ else -}}
         "otelcol_{{ $name }}",
+        {{ end -}}
         metric.WithDescription("{{ $metric.Description }}{{ $metric.Stability }}"),
         metric.WithUnit("{{ $metric.Unit }}"),
         {{ if eq $metric.Data.Type "Histogram" -}}

cmd/mdatagen/internal/templates/telemetrytest.go.tmpl

@@ -32,7 +32,11 @@ return set
 
 func AssertEqual{{ $name.Render }}(t *testing.T, tt *componenttest.Telemetry, dps []metricdata.{{- if eq $metric.Data.Type "Histogram" }} {{$metric.Data.Type}} {{- end }}DataPoint[{{ $metric.Data.BasicType }}], opts ...metricdatatest.Option) {
 	want := metricdata.Metrics{
+		{{ if $metric.Prefix -}}
+		Name:        "{{ $metric.Prefix }}{{ $name }}",
+		{{ else -}}
 		Name:        "otelcol_{{ $name }}",
+		{{ end -}}
 		Description: "{{ $metric.Description }}{{ $metric.Stability }}",
 		Unit:        "{{ $metric.Unit }}",
 		Data:        metricdata.{{ $metric.Data.Type }}[{{ $metric.Data.BasicType }}]{
@@ -45,7 +49,11 @@ func AssertEqual{{ $name.Render }}(t *testing.T, tt *componenttest.Telemetry, dp
 			DataPoints: dps,
 		},
 	}
+	{{ if $metric.Prefix -}}
+	got, err := tt.GetMetric("{{ $metric.Prefix }}{{ $name }}")
+	{{ else -}}
 	got, err := tt.GetMetric("otelcol_{{ $name }}")
+	{{ end -}}
 	require.NoError(t, err)
 	metricdatatest.AssertEqual(t, want, got, opts...)
 }

service/documentation.md

@@ -6,6 +6,30 @@
 
 The following telemetry is emitted by this component.
 
+### otelcol.connector.consumed.items
+
+Number of items passed to the connector.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {item} | Sum | Int | true |
+
+### otelcol.connector.produced.items
+
+Number of items emitted from the connector.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {item} | Sum | Int | true |
+
+### otelcol.exporter.consumed.items
+
+Number of items passed to the exporter.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {item} | Sum | Int | true |
+
 ### otelcol_process_cpu_seconds
 
 Total CPU user and system time in seconds [alpha]
@@ -53,3 +77,27 @@ Uptime of the process [alpha]
 | Unit | Metric Type | Value Type | Monotonic |
 | ---- | ----------- | ---------- | --------- |
 | s | Sum | Double | true |
+
+### otelcol.processor.consumed.items
+
+Number of items passed to the processor.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {item} | Sum | Int | true |
+
+### otelcol.processor.produced.items
+
+Number of items emitted from the processor.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {item} | Sum | Int | true |
+
+### otelcol.receiver.produced.items
+
+Number of items emitted from the receiver.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {item} | Sum | Int | true |