otlptracehttp, otlpmetrichttp: Retry for 502, 504 HTTP statuses (#4670)

exporters/otlp/otlptrace/otlptracehttp/client.go

@@ -190,7 +190,10 @@ func (d *client) UploadTraces(ctx context.Context, protoSpans []*tracepb.Resourc
 			}
 			return nil
 
-		case sc == http.StatusTooManyRequests, sc == http.StatusServiceUnavailable:
+		case sc == http.StatusTooManyRequests,
+			sc == http.StatusBadGateway,
+			sc == http.StatusServiceUnavailable,
+			sc == http.StatusGatewayTimeout:
 			// Retry-able failures.  Drain the body to reuse the connection.
 			if _, err := io.Copy(io.Discard, resp.Body); err != nil {
 				otel.Handle(err)

exporters/otlp/otlptrace/otlptracehttp/client_test.go

@@ -95,7 +95,7 @@ func TestEndToEnd(t *testing.T) {
 				}),
 			},
 			mcCfg: mockCollectorConfig{
-				InjectHTTPStatus: []int{503, 503},
+				InjectHTTPStatus: []int{503, 502},
 			},
 		},
 		{
@@ -110,7 +110,7 @@ func TestEndToEnd(t *testing.T) {
 				}),
 			},
 			mcCfg: mockCollectorConfig{
-				InjectHTTPStatus: []int{503},
+				InjectHTTPStatus: []int{504},
 				InjectResponseHeader: []map[string]string{
 					{"Retry-After": "10"},
 				},