Prometheus: (Chore/Instrumentation) add trace spans for result proces… (#67858)

Prometheus: (Chore/Instrumentation) add trace spans for result processing

pkg/tsdb/prometheus/querydata/response.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/models"
 	"github.com/grafana/grafana/pkg/tsdb/prometheus/querydata/exemplar"
+	"github.com/grafana/grafana/pkg/tsdb/prometheus/utils"
 	"github.com/grafana/grafana/pkg/util/converter"
 )
 
@@ -24,6 +25,9 @@ func (s *QueryData) parseResponse(ctx context.Context, q *models.Query, res *htt
 		}
 	}()
 
+	ctx, endSpan := utils.StartTrace(ctx, s.tracer, "datasource.prometheus.parseResponse", []utils.Attribute{})
+	defer endSpan()
+
 	iter := jsoniter.Parse(jsoniter.ConfigDefault, res.Body, 1024)
 	r := converter.ReadPrometheusStyleResult(iter, converter.Options{
 		MatrixWideSeries: s.enableWideSeries,
@@ -46,13 +50,15 @@ func (s *QueryData) parseResponse(ctx context.Context, q *models.Query, res *htt
 	}
 
 	if r.Error == nil {
-		r = s.processExemplars(q, r)
+		r = s.processExemplars(ctx, q, r)
 	}
 
 	return r
 }
 
-func (s *QueryData) processExemplars(q *models.Query, dr backend.DataResponse) backend.DataResponse {
+func (s *QueryData) processExemplars(ctx context.Context, q *models.Query, dr backend.DataResponse) backend.DataResponse {
+	_, endSpan := utils.StartTrace(ctx, s.tracer, "datasource.prometheus.processExemplars", []utils.Attribute{})
+	defer endSpan()
 	sampler := s.exemplarSampler()
 	labelTracker := exemplar.NewLabelTracker()