Fix bugs and failed testcases

internal/util/statistics.go

@@ -4,7 +4,10 @@
 // license that can be found in the LICENSE file.
 package util
 
-import "golang.org/x/exp/constraints"
+import (
+	"github.com/ClusterCockpit/cc-backend/pkg/schema"
+	"golang.org/x/exp/constraints"
+)
 
 func Min[T constraints.Ordered](a, b T) T {
 	if a < b {
@@ -19,3 +22,15 @@ func Max[T constraints.Ordered](a, b T) T {
 	}
 	return b
 }
+
+func LoadJobStat(job *schema.JobMeta, metric string) float64 {
+	if stats, ok := job.Statistics[metric]; ok {
+		if metric == "mem_used" {
+			return stats.Max
+		} else {
+			return stats.Avg
+		}
+	}
+
+	return 0.0
+}