[exporter/prometheusremotewrite] Fix: Don't drop batch in case of failure to translate metrics

.chloggen/prw_failure_translate.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: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: prometheusremotewriteexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Don't drop all metrics in a batch in case some of them cannot be translated from Otel to Prometheus.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29729]
+
+# (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:
+
+# 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]

exporter/prometheusremotewriteexporter/exporter.go

@@ -26,6 +26,7 @@ import (
 	"go.opentelemetry.io/collector/exporter/exporterhelper"
 	"go.opentelemetry.io/collector/pdata/pmetric"
 	"go.uber.org/multierr"
+	"go.uber.org/zap"
 
 	prometheustranslator "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/prometheus"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/prometheusremotewrite"
@@ -134,15 +135,17 @@ func (prwe *prwExporter) PushMetrics(ctx context.Context, md pmetric.Metrics) er
 
 		tsMap, err := prometheusremotewrite.FromMetrics(md, prwe.exporterSettings)
 		if err != nil {
-			err = consumererror.NewPermanent(err)
+			prwe.settings.Logger.Warn("Failed to translate metrics: %s", zap.Error(err))
+			prwe.settings.Logger.Warn("Exporting remaining %s metrics.", zap.Int("converted", len(tsMap)))
 		}
 
 		var m []*prompb.MetricMetadata
 		if prwe.exporterSettings.SendMetadata {
 			m = prometheusremotewrite.OtelMetricsToMetadata(md, prwe.exporterSettings.AddMetricSuffixes)
 		}
+
 		// Call export even if a conversion error, since there may be points that were successfully converted.
-		return multierr.Combine(err, prwe.handleExport(ctx, tsMap, m))
+		return prwe.handleExport(ctx, tsMap, m)
 	}
 }
 

exporter/prometheusremotewriteexporter/exporter_test.go

@@ -419,6 +419,11 @@ func Test_PushMetrics(t *testing.T) {
 
 	emptySummaryBatch := getMetricsFromMetricList(invalidMetrics[emptySummary])
 
+	// partial success (or partial failure) cases
+
+	partialSuccess1 := getMetricsFromMetricList(validMetrics1[validSum], validMetrics2[validSum],
+		validMetrics1[validIntGauge], validMetrics2[validIntGauge], invalidMetrics[emptyGauge])
+
 	// staleNaN cases
 	staleNaNHistogramBatch := getMetricsFromMetricList(staleNaNMetrics[staleNaNHistogram])
 	staleNaNEmptyHistogramBatch := getMetricsFromMetricList(staleNaNMetrics[staleNaNEmptyHistogram])
@@ -469,7 +474,6 @@ func Test_PushMetrics(t *testing.T) {
 			name:             "invalid_type_case",
 			metrics:          invalidTypeBatch,
 			httpResponseCode: http.StatusAccepted,
-			returnErr:        true,
 		},
 		{
 			name:               "intSum_case",
@@ -570,28 +574,31 @@ func Test_PushMetrics(t *testing.T) {
 			metrics:          emptyDoubleGaugeBatch,
 			reqTestFunc:      checkFunc,
 			httpResponseCode: http.StatusAccepted,
-			returnErr:        true,
 		},
 		{
 			name:             "emptyCumulativeSum_case",
 			metrics:          emptyCumulativeSumBatch,
 			reqTestFunc:      checkFunc,
 			httpResponseCode: http.StatusAccepted,
-			returnErr:        true,
 		},
 		{
 			name:             "emptyCumulativeHistogram_case",
 			metrics:          emptyCumulativeHistogramBatch,
 			reqTestFunc:      checkFunc,
 			httpResponseCode: http.StatusAccepted,
-			returnErr:        true,
 		},
 		{
 			name:             "emptySummary_case",
 			metrics:          emptySummaryBatch,
 			reqTestFunc:      checkFunc,
 			httpResponseCode: http.StatusAccepted,
-			returnErr:        true,
+		},
+		{
+			name:               "partialSuccess_case",
+			metrics:            partialSuccess1,
+			reqTestFunc:        checkFunc,
+			httpResponseCode:   http.StatusAccepted,
+			expectedTimeSeries: 4,
 		},
 		{
 			name:               "staleNaNIntGauge_case",