Remove special validation error handling

README.md

@@ -138,26 +138,6 @@ synchronous and asynchronous UpDownCounter instruments are specified
 to use cumulative temporality in OpenTelemetry metrics SDKs
 independent of the temporality preference.
 
-### Metrics validation errors
-
-Lightstep performs a number of validation steps over metrics data
-before accepting it.  When an OTLP Metrics export request is
-successful but data is completely or partially rejected for any
-reason, the outcome is detailed using Lightstep-specific response
-headers. 
-
-These headers predate [work in OpenTelemetry on returning partial
-success](https://github.com/open-telemetry/opentelemetry-proto/pull/390).
-Lightstep expects to use standard OTLP fields to convey these
-partially-successful outcomes in the future.
-
-Validation errors are generally repetitive.  Lightstep limits the size
-of each partial-success response to lower the overhead associated with
-these responses using random selection.
-
-The launcher contains special code to interpret these headers and
-direct them to the standard OpenTelemetry-Go error handler.
-
 ------
 
 *Made with*

pipelines/metrics.go

@@ -16,9 +16,7 @@ package pipelines
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
-	"strconv"
 	"strings"
 	"time"
 
@@ -30,7 +28,6 @@ import (
 
 	hostMetrics "go.opentelemetry.io/contrib/instrumentation/host"
 	runtimeMetrics "go.opentelemetry.io/contrib/instrumentation/runtime"
-	"go.opentelemetry.io/otel"
 
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
 	"go.opentelemetry.io/otel/metric"
@@ -43,9 +40,7 @@ import (
 	processor "go.opentelemetry.io/otel/sdk/metric/processor/basic"
 	selector "go.opentelemetry.io/otel/sdk/metric/selector/simple"
 
-	"google.golang.org/grpc"
 	"google.golang.org/grpc/encoding/gzip"
-	"google.golang.org/grpc/metadata"
 )
 
 func NewMetricsPipeline(c PipelineConfig) (func() error, error) {
@@ -128,86 +123,12 @@ func NewMetricsPipeline(c PipelineConfig) (func() error, error) {
 	return shutdown, nil
 }
 
-var errNoSingleCount = fmt.Errorf("no count")
-
-func singleCount(values []string) (int, error) {
-	if len(values) != 1 {
-		return 0, errNoSingleCount
-	}
-	return strconv.Atoi(values[0])
-}
-
-type dropExample struct {
-	Reason string   `json:"reason"`
-	Names  []string `json:"names"`
-}
-
-type dropSummary struct {
-	Dropped struct {
-		Points  int `json:"points,omitempty"`
-		Metrics int `json:"metrics,omitempty"`
-	} `json:"dropped,omitempty"`
-	Examples []dropExample `json:"examples,omitempty"`
-}
-
-func (ds *dropSummary) Empty() bool {
-	return len(ds.Examples) == 0 && ds.Dropped.Points == 0 && ds.Dropped.Metrics == 0
-}
-
-func interceptor(
-	ctx context.Context,
-	method string,
-	req, reply interface{},
-	cc *grpc.ClientConn,
-	invoker grpc.UnaryInvoker,
-	opts ...grpc.CallOption,
-) error {
-	const invalidTrailerPrefix = "otlp-invalid-"
-
-	var md metadata.MD
-	err := invoker(ctx, method, req, reply, cc, append(opts, grpc.Trailer(&md))...)
-	if err == nil && md != nil {
-		var ds dropSummary
-		for key, values := range md {
-			key = strings.ToLower(key)
-			if !strings.HasPrefix(key, "otlp-") {
-				continue
-			}
-
-			if key == "otlp-points-dropped" {
-				if points, err := singleCount(values); err == nil {
-					ds.Dropped.Points = points
-				}
-			} else if key == "otlp-metrics-dropped" {
-				if metrics, err := singleCount(values); err == nil {
-					ds.Dropped.Metrics = metrics
-				}
-			} else if strings.HasPrefix(key, invalidTrailerPrefix) {
-				key = key[len(invalidTrailerPrefix):]
-				key = strings.ReplaceAll(key, "-", " ")
-				ds.Examples = append(ds.Examples, dropExample{
-					Reason: key,
-					Names:  values,
-				})
-			}
-		}
-		if !ds.Empty() {
-			data, _ := json.Marshal(ds)
-			otel.Handle(fmt.Errorf("metrics partial failure: %v", string(data)))
-		}
-	}
-	return err
-}
-
 func (c PipelineConfig) newClient() otlpmetric.Client {
 	return otlpmetricgrpc.NewClient(
 		c.secureMetricOption(),
 		otlpmetricgrpc.WithEndpoint(c.Endpoint),
 		otlpmetricgrpc.WithHeaders(c.Headers),
 		otlpmetricgrpc.WithCompressor(gzip.Name),
-		otlpmetricgrpc.WithDialOption(
-			grpc.WithUnaryInterceptor(interceptor),
-		),
 	)
 }