no append if ErrNoHostOrMetric fired

pkg/metricstore/api.go

@@ -13,6 +13,7 @@ import (
 	"fmt"
 	"math"
 
+	cclog "github.com/ClusterCockpit/cc-lib/v2/ccLogger"
 	"github.com/ClusterCockpit/cc-lib/v2/schema"
 	"github.com/ClusterCockpit/cc-lib/v2/util"
 )
@@ -280,20 +281,16 @@ func FetchData(req APIQueryRequest) (*APIQueryResponse, error) {
 
 			data.Data, data.From, data.To, data.Resolution, err = ms.Read(sel, query.Metric, req.From, req.To, query.Resolution)
 			if err != nil {
-				// Check a special case where only the metric or host.
+				// Skip Error If Just Missing Host or Metric, Continue
-				// Dont send errors, instead just send empty array
+				// Empty Return For Metric Handled Gracefully By Frontend
-				// where frontend already renders error for empty array.
+				if err != ErrNoHostOrMetric {
-				if err == ErrNoHostOrMetric {
-					data.Data = make([]schema.Float, 0)
-					data.From = req.From
-					data.To = req.To
-					data.Resolution = query.Resolution
-				} else {
 					msg := err.Error()
 					data.Error = &msg
 					res = append(res, data)
-					continue
+				} else {
+					cclog.Warnf("failed to fetch '%s' from host '%s' (cluster: %s): %s", query.Metric, query.Hostname, req.Cluster, err.Error())
 				}
+				continue
 			}
 
 			if req.WithStats {

pkg/metricstore/query.go

@@ -104,6 +104,11 @@ func (ccms *InternalMetricStore) LoadData(
 	var errors []string
 	jobData := make(schema.JobData)
 	for i, row := range resBody.Results {
+		if len(row) == 0 {
+			// No Data Found For Metric, Logged in FetchData to Warn
+			continue
+		}
+
 		query := req.Queries[i]
 		metric := query.Metric
 		scope := assignedScope[i]
@@ -229,7 +234,7 @@ func buildQueries(
 	for _, metric := range metrics {
 		mc := archive.GetMetricConfig(job.Cluster, metric)
 		if mc == nil {
-			cclog.Infof("metric '%s' is not specified for cluster '%s'", metric, job.Cluster)
+			cclog.Warnf("metric '%s' is not specified for cluster '%s'", metric, job.Cluster)
 			continue
 		}
 
@@ -535,11 +540,15 @@ func (ccms *InternalMetricStore) LoadStats(
 
 	stats := make(map[string]map[string]schema.MetricStatistics, len(metrics))
 	for i, res := range resBody.Results {
+		if len(res) == 0 {
+			// No Data Found For Metric, Logged in FetchData to Warn
+			continue
+		}
 		query := req.Queries[i]
 		metric := query.Metric
 		data := res[0]
 		if data.Error != nil {
-			cclog.Errorf("fetching %s for node %s failed: %s", metric, query.Hostname, *data.Error)
+			cclog.Warnf("fetching %s for node %s failed: %s", metric, query.Hostname, *data.Error)
 			continue
 		}
 
@@ -609,6 +618,10 @@ func (ccms *InternalMetricStore) LoadScopedStats(
 	scopedJobStats := make(schema.ScopedJobStats)
 
 	for i, row := range resBody.Results {
+		if len(row) == 0 {
+			// No Data Found For Metric, Logged in FetchData to Warn
+			continue
+		}
 		query := req.Queries[i]
 		metric := query.Metric
 		scope := assignedScope[i]
@@ -717,6 +730,11 @@ func (ccms *InternalMetricStore) LoadNodeData(
 	var errors []string
 	data := make(map[string]map[string][]*schema.JobMetric)
 	for i, res := range resBody.Results {
+		if len(res) == 0 {
+			// No Data Found For Metric, Logged in FetchData to Warn
+			continue
+		}
+
 		var query APIQuery
 		if resBody.Queries != nil {
 			query = resBody.Queries[i]
@@ -816,6 +834,10 @@ func (ccms *InternalMetricStore) LoadNodeListData(
 	var errors []string
 	data := make(map[string]schema.JobData)
 	for i, row := range resBody.Results {
+		if len(row) == 0 {
+			// No Data Found For Metric, Logged in FetchData to Warn
+			continue
+		}
 		var query APIQuery
 		if resBody.Queries != nil {
 			query = resBody.Queries[i]