fix staticweight bug

Former-commit-id: 982092d0ae6466d1be3a5ee27bfa80aab0e812bc

api/internal/scheduler/algorithm/weightDistributing/weightDistributing.go

@@ -1,6 +1,7 @@
 package weightDistributing
 
 import (
+	"errors"
 	"math"
 )
 
@@ -10,7 +11,7 @@ type Weight struct {
 	Replica int32
 }
 
-func DistributeReplicas(weights []*Weight, replicas int32) {
+func DistributeReplicas(weights []*Weight, replicas int32) error {
 
 	var weightSum int32
 	weightSum = 0
@@ -18,6 +19,10 @@ func DistributeReplicas(weights []*Weight, replicas int32) {
 		weightSum += w.Weight
 	}
 
+	if weightSum == 0 {
+		return errors.New("static weights are empty")
+	}
+
 	weightRatio := make([]float64, len(weights))
 	for i, w := range weights {
 		weightRatio[i] = float64(w.Weight) / float64(weightSum)
@@ -69,4 +74,5 @@ func DistributeReplicas(weights []*Weight, replicas int32) {
 			rest++
 		}
 	}
+	return nil
 }

api/internal/scheduler/strategy/staticWeight.go

@@ -35,7 +35,10 @@ func (s *StaticWeightStrategy) Schedule() ([]*AssignedCluster, error) {
 		weights = append(weights, weight)
 	}
 
-	weightDistributing.DistributeReplicas(weights, s.replicas)
+	err := weightDistributing.DistributeReplicas(weights, s.replicas)
+	if err != nil {
+		return nil, err
+	}
 
 	var results []*AssignedCluster
 	for _, weight := range weights {