fix: wrong reduce lantency metric (#46233)

#46248

Signed-off-by: wgcn <[email protected]>
Co-authored-by: wgcn <[email protected]>

Author: wg1026688210

internal/querynodev2/handlers.go

@@ -435,6 +435,12 @@ func (node *QueryNode) searchChannel(ctx context.Context, req *querypb.SearchReq
 		reduce.NewReduceSearchResultInfo(req.GetReq().GetNq(),
 			req.GetReq().GetTopk()).WithMetricType(req.GetReq().GetMetricType()).WithGroupByField(req.GetReq().GetGroupByFieldId()).
 			WithGroupSize(req.GetReq().GetGroupSize()).WithAdvance(req.GetReq().GetIsAdvanced()))
+
+	reduceLatency := tr.RecordSpan()
+	metrics.QueryNodeReduceLatency.
+		WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.SearchLabel, metrics.ReduceShards, metrics.BatchReduce).
+		Observe(float64(reduceLatency.Milliseconds()))
+
 	if err != nil {
 		return nil, err
 	}

internal/querynodev2/services.go

@@ -878,13 +878,8 @@ func (node *QueryNode) Search(ctx context.Context, req *querypb.SearchRequest) (
 		return resp, nil
 	}
 
-	tr.RecordSpan()
 	ret.Status = merr.Success()
 
-	reduceLatency := tr.RecordSpan()
-	metrics.QueryNodeReduceLatency.
-		WithLabelValues(fmt.Sprint(node.GetNodeID()), metrics.SearchLabel, metrics.ReduceShards, metrics.BatchReduce).
-		Observe(float64(reduceLatency.Milliseconds()))
 	metrics.QueryNodeExecuteCounter.WithLabelValues(strconv.FormatInt(node.GetNodeID(), 10), metrics.SearchLabel).
 		Add(float64(proto.Size(req)))