3 files changed, 19 insertions, 12 deletions
diff --git a/weed/wdclient/masterclient.go b/weed/wdclient/masterclient.go
index df8c186f2..e39b9dfdf 100644
--- a/weed/wdclient/masterclient.go
+++ b/weed/wdclient/masterclient.go
@@ -24,14 +24,14 @@ type MasterClient struct {
 	vidMap
 }
 
-func NewMasterClient(grpcDialOption grpc.DialOption, clientType string, clientHost string, clientGrpcPort uint32, masters []string) *MasterClient {
+func NewMasterClient(grpcDialOption grpc.DialOption, clientType string, clientHost string, clientGrpcPort uint32, clientDataCenter string, masters []string) *MasterClient {
 	return &MasterClient{
 		clientType:     clientType,
 		clientHost:     clientHost,
 		grpcPort:       clientGrpcPort,
 		masters:        masters,
 		grpcDialOption: grpcDialOption,
-		vidMap:         newVidMap(),
+		vidMap:         newVidMap(clientDataCenter),
 	}
 }
 
@@ -89,7 +89,7 @@ func (mc *MasterClient) tryAllMasters() {
 		}
 
 		mc.currentMaster = ""
-		mc.vidMap = newVidMap()
+		mc.vidMap = newVidMap("")
 	}
 }
 
@@ -130,8 +130,9 @@ func (mc *MasterClient) tryConnectToMaster(master string) (nextHintedLeader stri
 
 			// process new volume location
 			loc := Location{
-				Url:       volumeLocation.Url,
-				PublicUrl: volumeLocation.PublicUrl,
+				Url:        volumeLocation.Url,
+				PublicUrl:  volumeLocation.PublicUrl,
+				DataCenter: volumeLocation.DataCenter,
 			}
 			for _, newVid := range volumeLocation.NewVids {
 				glog.V(1).Infof("%s: %s masterClient adds volume %d", mc.clientType, loc.Url, newVid)
diff --git a/weed/wdclient/vid_map.go b/weed/wdclient/vid_map.go
index cee2da6e1..773da0191 100644
--- a/weed/wdclient/vid_map.go
+++ b/weed/wdclient/vid_map.go
@@ -16,20 +16,22 @@ const (
 )
 
 type Location struct {
-	Url       string `json:"url,omitempty"`
-	PublicUrl string `json:"publicUrl,omitempty"`
+	Url        string `json:"url,omitempty"`
+	PublicUrl  string `json:"publicUrl,omitempty"`
+	DataCenter string `json:"dataCenter,omitempty"`
 }
 
 type vidMap struct {
 	sync.RWMutex
 	vid2Locations map[uint32][]Location
-
-	cursor int32
+	DataCenter    string
+	cursor        int32
 }
 
-func newVidMap() vidMap {
+func newVidMap(dataCenter string) vidMap {
 	return vidMap{
 		vid2Locations: make(map[uint32][]Location),
+		DataCenter:    dataCenter,
 		cursor:        -1,
 	}
 }
@@ -56,7 +58,11 @@ func (vc *vidMap) LookupVolumeServerUrl(vid string) (serverUrls []string, err er
 		return nil, fmt.Errorf("volume %d not found", id)
 	}
 	for _, loc := range locations {
-		serverUrls = append(serverUrls, loc.Url)
+		if vc.DataCenter == "" || loc.DataCenter == "" || vc.DataCenter != loc.DataCenter {
+			serverUrls = append(serverUrls, loc.Url)
+		} else {
+			serverUrls = append([]string{loc.Url}, serverUrls...)
+		}
 	}
 	return
 }
diff --git a/weed/wdclient/vid_map_test.go b/weed/wdclient/vid_map_test.go
index 87be2fc25..0cea698ac 100644
--- a/weed/wdclient/vid_map_test.go
+++ b/weed/wdclient/vid_map_test.go
@@ -45,7 +45,7 @@ func TestLocationIndex(t *testing.T) {
 	mustOk(7, maxCursorIndex, 0)
 
 	// test with constructor
-	vm = newVidMap()
+	vm = newVidMap("")
 	length := 7
 	for i := 0; i < 100; i++ {
 		got, err := vm.getLocationIndex(length)