diff --git a/weed/topology/data_center.go b/weed/topology/data_center.go
index 60d91ba6d..304a5ccae 100644
--- a/weed/topology/data_center.go
+++ b/weed/topology/data_center.go
@@ -2,6 +2,7 @@ package topology
 
 import (
 	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
+	"golang.org/x/exp/slices"
 )
 
 type DataCenter struct {
@@ -30,15 +31,24 @@ func (dc *DataCenter) GetOrCreateRack(rackName string) *Rack {
 	return rack
 }
 
-func (dc *DataCenter) ToMap() interface{} {
-	m := make(map[string]interface{})
-	m["Id"] = dc.Id()
-	var racks []interface{}
+type DataCenterMap struct {
+	Id    NodeId    `json:"Id"`
+	Racks []RackMap `json:"Racks"`
+}
+
+func (dc *DataCenter) ToMap() DataCenterMap {
+	m := DataCenterMap{}
+	m.Id = dc.Id()
+	var racks []RackMap
 	for _, c := range dc.Children() {
 		rack := c.(*Rack)
 		racks = append(racks, rack.ToMap())
 	}
-	m["Racks"] = racks
+
+	slices.SortFunc(racks, func(a, b RackMap) bool {
+		return a.Id < b.Id
+	})
+	m.Racks = racks
 	return m
 }
 
diff --git a/weed/topology/data_node.go b/weed/topology/data_node.go
index 6bdbd965f..6a24c4a49 100644
--- a/weed/topology/data_node.go
+++ b/weed/topology/data_node.go
@@ -217,10 +217,19 @@ func (dn *DataNode) ServerAddress() pb.ServerAddress {
 	return pb.NewServerAddress(dn.Ip, dn.Port, dn.GrpcPort)
 }
 
-func (dn *DataNode) ToMap() interface{} {
-	ret := make(map[string]interface{})
-	ret["Url"] = dn.Url()
-	ret["PublicUrl"] = dn.PublicUrl
+type DataNodeMap struct {
+	Url       string `json:"Url"`
+	PublicUrl string `json:"PublicUrl"`
+	Volumes   int64  `json:"Volumes"`
+	EcShards  int64  `json:"EcShards"`
+	Max       int64  `json:"Max"`
+	VolumeIds string `json:"VolumeIds"`
+}
+
+func (dn *DataNode) ToMap() DataNodeMap {
+	ret := DataNodeMap{}
+	ret.Url = dn.Url()
+	ret.PublicUrl = dn.PublicUrl
 
 	// aggregated volume info
 	var volumeCount, ecShardCount, maxVolumeCount int64
@@ -236,10 +245,10 @@ func (dn *DataNode) ToMap() interface{} {
 		volumeIds += " " + d.GetVolumeIds()
 	}
 
-	ret["Volumes"] = volumeCount
-	ret["EcShards"] = ecShardCount
-	ret["Max"] = maxVolumeCount
-	ret["VolumeIds"] = volumeIds
+	ret.Volumes = volumeCount
+	ret.EcShards = ecShardCount
+	ret.Max = maxVolumeCount
+	ret.VolumeIds = volumeIds
 
 	return ret
 }
diff --git a/weed/topology/rack.go b/weed/topology/rack.go
index cd09746b2..0588dfa7d 100644
--- a/weed/topology/rack.go
+++ b/weed/topology/rack.go
@@ -4,6 +4,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
 	"github.com/chrislusf/seaweedfs/weed/storage/types"
 	"github.com/chrislusf/seaweedfs/weed/util"
+	"golang.org/x/exp/slices"
 	"time"
 )
 
@@ -53,15 +54,25 @@ func (r *Rack) GetOrCreateDataNode(ip string, port int, grpcPort int, publicUrl
 	return dn
 }
 
-func (r *Rack) ToMap() interface{} {
-	m := make(map[string]interface{})
-	m["Id"] = r.Id()
-	var dns []interface{}
+type RackMap struct {
+	Id        NodeId        `json:"Id"`
+	DataNodes []DataNodeMap `json:"DataNodes"`
+}
+
+func (r *Rack) ToMap() RackMap {
+	m := RackMap{}
+	m.Id = r.Id()
+	var dns []DataNodeMap
 	for _, c := range r.Children() {
 		dn := c.(*DataNode)
 		dns = append(dns, dn.ToMap())
 	}
-	m["DataNodes"] = dns
+
+	slices.SortFunc(dns, func(a, b DataNodeMap) bool {
+		return a.Url < b.Url
+	})
+
+	m.DataNodes = dns
 	return m
 }
 
diff --git a/weed/topology/topology_map.go b/weed/topology/topology_map.go
index 0fedb6221..b6585e964 100644
--- a/weed/topology/topology_map.go
+++ b/weed/topology/topology_map.go
@@ -1,17 +1,32 @@
 package topology
 
-import "github.com/chrislusf/seaweedfs/weed/pb/master_pb"
+import (
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
+	"golang.org/x/exp/slices"
+)
+
+type TopologyMap struct {
+	Max         int64           `json:"Max"`
+	Free        int64           `json:"Free"`
+	DataCenters []DataCenterMap `json:"DataCenters"`
+	Layouts     []interface{}   `json:"Layouts"`
+}
 
 func (t *Topology) ToMap() interface{} {
-	m := make(map[string]interface{})
-	m["Max"] = t.diskUsages.GetMaxVolumeCount()
-	m["Free"] = t.diskUsages.FreeSpace()
-	var dcs []interface{}
+	m := TopologyMap{}
+	m.Max = t.diskUsages.GetMaxVolumeCount()
+	m.Free = t.diskUsages.FreeSpace()
+	var dcs []DataCenterMap
 	for _, c := range t.Children() {
 		dc := c.(*DataCenter)
 		dcs = append(dcs, dc.ToMap())
 	}
-	m["DataCenters"] = dcs
+
+	slices.SortFunc(dcs, func(a, b DataCenterMap) bool {
+		return a.Id < b.Id
+	})
+
+	m.DataCenters = dcs
 	var layouts []interface{}
 	for _, col := range t.collectionMap.Items() {
 		c := col.(*Collection)
@@ -23,7 +38,7 @@ func (t *Topology) ToMap() interface{} {
 			}
 		}
 	}
-	m["Layouts"] = layouts
+	m.Layouts = layouts
 	return m
 }