fix: Volume top metrics are not available for Flexgroup volumes

cmd/collectors/restperf/plugins/volume/volume_test.go

@@ -92,13 +92,12 @@ func runVolumeTest(t *testing.T, createVolume func(params *node.Node) plugin.Plu
 	assert.Nil(t, err)
 
 	// Verify the output
-	assert.Equal(t, len(output), 2)
+	assert.Equal(t, len(output), 1)
 
-	cache := output[0]
-	volumeAggrmetric := output[1]
+	volumeAggrmetric := output[0]
 
-	// Check for flexgroup instance
-	flexgroupInstance := cache.GetInstance("svm1.RahulTest")
+	// Check for flexgroup instance in the modified data matrix
+	flexgroupInstance := data.GetInstance("svm1.RahulTest")
 	assert.NotNil(t, flexgroupInstance)
 
 	// Check for flexgroup constituents
@@ -118,44 +117,39 @@ func runVolumeTest(t *testing.T, createVolume func(params *node.Node) plugin.Plu
 	// Verify aggregated ops metric
 	if setMetricNaN {
 		assert.True(t, flexgroupMetricInstance.IsExportable())
-		_, ok := cache.GetMetric("read_ops").GetValueFloat64(flexgroupInstance)
+		_, ok := data.GetMetric("read_ops").GetValueFloat64(flexgroupInstance)
 		assert.False(t, ok)
 	} else {
-		value, ok := cache.GetMetric("read_ops").GetValueFloat64(flexgroupInstance)
+		value, ok := data.GetMetric("read_ops").GetValueFloat64(flexgroupInstance)
 		assert.True(t, ok)
 		assert.Equal(t, value, 20.0)
 	}
 
 	// Verify aggregated latency metric (weighted average)
 	if setMetricNaN {
-		_, ok := cache.GetMetric("read_latency").GetValueFloat64(flexgroupInstance)
+		_, ok := data.GetMetric("read_latency").GetValueFloat64(flexgroupInstance)
 		assert.False(t, ok)
 	} else {
 		expectedLatency := (20*4 + 30*6 + 40*10) / 20.0
-		value, ok := cache.GetMetric("read_latency").GetValueFloat64(flexgroupInstance)
+		value, ok := data.GetMetric("read_latency").GetValueFloat64(flexgroupInstance)
 		assert.True(t, ok)
 		assert.Equal(t, value, expectedLatency)
 	}
 
 	// Check for simple volume instance
-	simpleVolumeInstance := cache.GetInstance("svm1.SimpleVolume")
-	assert.Nil(t, simpleVolumeInstance)
+	simpleVolumeInstance := data.GetInstance("SimpleVolume")
+	assert.NotNil(t, simpleVolumeInstance)
+	assert.Equal(t, simpleVolumeInstance.GetLabel(StyleType), "flexvol")
 
-	// count instances in both data and cache
+	// count exportable instances
 	currentCount := 0
 	for _, i := range data.GetInstances() {
 		if i.IsExportable() {
 			currentCount++
 		}
 	}
 
-	for _, i := range cache.GetInstances() {
-		if i.IsExportable() {
-			currentCount++
-		}
-	}
-
-	// Verify the number of instances in the cache
+	// Verify the number of exportable instances in the data matrix
 	assert.Equal(t, currentCount, expectedCount)
 }
 

cmd/collectors/volume.go

@@ -222,10 +222,42 @@ func ProcessFlexGroupData(logger *slog.Logger, data *matrix.Matrix, style string
 		}
 	}
 
+	// Merge FlexGroup instances from cache back to data matrix for downstream plugins like topclients
+	for fgKey, fgInstance := range cache.GetInstances() {
+		if !fgInstance.IsExportable() {
+			continue
+		}
+
+		dataInstance := data.GetInstance(fgKey)
+		if dataInstance == nil {
+			if dataInstance, err = data.NewInstance(fgKey); err != nil {
+				logger.Error("Failed to create instance in data matrix", slogx.Err(err), slog.String("key", fgKey))
+				continue
+			}
+			dataInstance.SetLabels(fgInstance.GetLabels())
+		}
+
+		for metricKey, cacheMetric := range cache.GetMetrics() {
+			if !cacheMetric.IsExportable() {
+				continue
+			}
+
+			dataMetric := data.GetMetric(metricKey)
+			if dataMetric == nil {
+				logger.Warn("Metric not found in data matrix, skipping", slog.String("metric", metricKey))
+				continue
+			}
+
+			if value, ok := cacheMetric.GetValueFloat64(fgInstance); ok {
+				dataMetric.SetValueFloat64(dataInstance, value)
+			}
+		}
+	}
+
 	if enableVolumeAggrMatrix {
-		return []*matrix.Matrix{cache, volumeAggrMatrix}, nil, nil
+		return []*matrix.Matrix{volumeAggrMatrix}, nil, nil
 	}
-	return []*matrix.Matrix{cache}, nil, nil
+	return nil, nil, nil
 }
 
 func ProcessFlexGroupFootPrint(data *matrix.Matrix, logger *slog.Logger) *matrix.Matrix {