Prevent to setup weight for all nodes every five seconds

Only replica sets with the vshard-storage role have weight attribute. We can use this to optimize setting of replica set weight.
There is two cases, when weight should not be set:
1. Current weight is null. It's mean, what this replica set isn't storage and weight wouldn't be applied.
2. Current weight of replica set is the same as weight specified in an annotation.

Author: Kasen

controllers/cluster_controller.go

@@ -31,6 +31,7 @@ package controllers
 import (
 	"context"
 	"fmt"
+	"strconv"
 	"strings"
 	"time"
 
@@ -314,6 +315,15 @@ func (r *ClusterReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 		stsAnnotations := sts.GetAnnotations()
 		weight := stsAnnotations["tarantool.io/replicaset-weight"]
 
+		current_weight, err := topologyClient.GetWeight(sts.GetLabels()["tarantool.io/replicaset-uuid"])
+		if err != nil {
+			return ctrl.Result{RequeueAfter: time.Duration(5 * time.Second)}, err
+		}
+
+		if current_weight == -1 || strconv.Itoa(current_weight) == weight {
+			continue
+		}
+
 		if weight == "0" {
 			reqLogger.Info("weight is set to 0, checking replicaset buckets for scheduled deletion")
 			data, err := topologyClient.GetServerStat()

controllers/topology/builtin.go

@@ -99,8 +99,9 @@ type ReplicasetsQueryResponse struct {
 
 // ReplicasetData .
 type ReplicasetData struct {
-	UUID  string   `json:"uuid"`
-	Roles []string `json:"roles"`
+	UUID   string   `json:"uuid"`
+	Roles  []string `json:"roles"`
+	Weight *int     `json:"weight"`
 }
 
 // Statistics .
@@ -143,6 +144,10 @@ var setRsWeightMutation = `mutation editReplicaset($uuid: String!, $weight: Floa
 	editReplicasetResponse: edit_replicaset(uuid: $uuid, weight: $weight)
 }`
 
+var getRsWeightQuery = `query ($uuid: String!) {
+	replicasets(uuid: $uuid) { weight }
+}`
+
 var setRsRolesMutation = `mutation editReplicaset($uuid: String!, $roles: [String!]) {
 	editReplicasetResponse: edit_replicaset(uuid: $uuid, roles: $roles)
 }`
@@ -349,6 +354,34 @@ func (s *BuiltInTopologyService) SetWeight(replicasetUUID string, replicaWeight
 	return errors.New("something really bad happened")
 }
 
+// GetWeight gets weight of a replicaset
+func (s *BuiltInTopologyService) GetWeight(replicasetUUID string) (int, error) {
+	client := graphql.NewClient(s.serviceHost, graphql.WithHTTPClient(&http.Client{Timeout: time.Duration(time.Second * 5)}))
+	req := graphql.NewRequest(getRsWeightQuery)
+
+	reqLogger := log.WithValues("namespace", "topology.builtin")
+
+	reqLogger.Info("getting cluster weight", "uuid", replicasetUUID)
+
+	req.Var("uuid", replicasetUUID)
+
+	resp := &ReplicasetsQueryResponse{}
+	if err := client.Run(context.TODO(), req, resp); err != nil {
+		return -1, err
+	}
+
+	if len(resp.Replicasets) == 0 {
+		return -1, fmt.Errorf("replicaset with uuid: '%s' not found", replicasetUUID)
+	}
+
+	// Instance without role vshard-storage returns null as weight
+	if resp.Replicasets[0].Weight == nil {
+		return -1, nil
+	}
+
+	return *resp.Replicasets[0].Weight, nil
+}
+
 // SetReplicasetRoles set roles list of replicaset in the Tarantool service
 func (s *BuiltInTopologyService) SetReplicasetRoles(replicasetUUID string, roles []string) error {
 	reqLogger := log.WithValues("namespace", "topology.builtin")