[exporterhelper] Add exporter dropped metrics

exporter/exporterhelper/common.go

@@ -309,6 +309,7 @@ func newBaseExporter(set exporter.Settings, signal component.DataType, osf obsre
 func (be *baseExporter) send(ctx context.Context, req Request) error {
 	err := be.queueSender.send(ctx, req)
 	if err != nil {
+		recordDroppedMetric(ctx, be.obsrep, int64(req.ItemsCount()))
 		be.set.Logger.Error("Exporting failed. Rejecting data."+be.exportFailureMessage,
 			zap.Error(err), zap.Int("rejected_items", req.ItemsCount()))
 	}
@@ -349,3 +350,15 @@ func (be *baseExporter) Shutdown(ctx context.Context) error {
 		// Last shutdown the wrapped exporter itself.
 		be.ShutdownFunc.Shutdown(ctx))
 }
+
+func recordDroppedMetric(ctx context.Context, obsrep *obsReport, count int64) {
+	if obsrep.dataType == component.DataTypeTraces {
+		obsrep.telemetryBuilder.ExporterDroppedSpans.Add(ctx, count)
+	}
+	if obsrep.dataType == component.DataTypeMetrics {
+		obsrep.telemetryBuilder.ExporterDroppedMetricPoints.Add(ctx, count)
+	}
+	if obsrep.dataType == component.DataTypeLogs {
+		obsrep.telemetryBuilder.ExporterDroppedLogRecords.Add(ctx, count)
+	}
+}

exporter/exporterhelper/documentation.md

@@ -6,6 +6,30 @@
 
 The following telemetry is emitted by this component.
 
+### otelcol_exporter_dropped_log_records
+
+Number of log records dropped after failing to export.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {records} | Sum | Int | true |
+
+### otelcol_exporter_dropped_metric_points
+
+Number of metric points dropped after failing to export.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {records} | Sum | Int | true |
+
+### otelcol_exporter_dropped_spans
+
+Number of spans dropped after failing to export.
+
+| Unit | Metric Type | Value Type | Monotonic |
+| ---- | ----------- | ---------- | --------- |
+| {records} | Sum | Int | true |
+
 ### otelcol_exporter_enqueue_failed_log_records
 
 Number of log records failed to be added to the sending queue.

exporter/exporterhelper/metadata.yaml

@@ -99,3 +99,27 @@ telemetry:
       gauge:
         value_type: int
         async: true
+
+    exporter_dropped_spans:
+      enabled: true
+      description: Number of spans dropped after failing to export.
+      unit: "{records}"
+      sum:
+        value_type: int
+        monotonic: true
+
+    exporter_dropped_metric_points:
+      enabled: true
+      description: Number of metric points dropped after failing to export.
+      unit: "{records}"
+      sum:
+        value_type: int
+        monotonic: true
+
+    exporter_dropped_log_records:
+      enabled: true
+      description: Number of log records dropped after failing to export.
+      unit: "{records}"
+      sum:
+        value_type: int
+        monotonic: true

exporter/exporterhelper/queue_sender.go

@@ -89,6 +89,7 @@ func newQueueSender(q exporterqueue.Queue[Request], set exporter.Settings, numCo
 	consumeFunc := func(ctx context.Context, req Request) error {
 		err := qs.nextSender.send(ctx, req)
 		if err != nil {
+			recordDroppedMetric(ctx, qs.obsrep, int64(req.ItemsCount()))
 			set.Logger.Error("Exporting failed. Dropping data."+exportFailureMessage,
 				zap.Error(err), zap.Int("dropped_items", req.ItemsCount()))
 		}