diff --git a/weed/server/filer_grpc_server.go b/weed/server/filer_grpc_server.go
index 13c66543b..6f7cf1ad6 100644
--- a/weed/server/filer_grpc_server.go
+++ b/weed/server/filer_grpc_server.go
@@ -238,7 +238,12 @@ func (fs *FilerServer) AssignVolume(ctx context.Context, req *filer_pb.AssignVol
 
 func (fs *FilerServer) DeleteCollection(ctx context.Context, req *filer_pb.DeleteCollectionRequest) (resp *filer_pb.DeleteCollectionResponse, err error) {
 
-	err = fs.filer.MasterClient.CollectionDelete(ctx, req.GetCollection())
+	err = fs.filer.MasterClient.WithClient(ctx, func(ctx context.Context, client master_pb.SeaweedClient) error {
+		_, err := client.CollectionDelete(ctx, &master_pb.CollectionDeleteRequest{
+			Name: req.GetCollection(),
+		})
+		return err
+	})
 
 	return &filer_pb.DeleteCollectionResponse{}, err
 }
diff --git a/weed/shell/command_collection_list.go b/weed/shell/command_collection_list.go
index 34a406d67..0797e56fb 100644
--- a/weed/shell/command_collection_list.go
+++ b/weed/shell/command_collection_list.go
@@ -3,6 +3,7 @@ package shell
 import (
 	"context"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
 	"io"
 )
 
@@ -21,9 +22,14 @@ func (c *commandCollectionList) Help() string {
 	return "# list all collections"
 }
 
-func (c *commandCollectionList) Do(args []string, commandEnv *commandEnv, writer io.Writer) error {
+func (c *commandCollectionList) Do(args []string, commandEnv *commandEnv, writer io.Writer) (err error) {
 
-	resp, err := commandEnv.masterClient.CollectionList(context.Background())
+	var resp *master_pb.CollectionListResponse
+
+	err = commandEnv.masterClient.WithClient(context.Background(), func(ctx context.Context, client master_pb.SeaweedClient) error {
+		resp, err = client.CollectionList(ctx, &master_pb.CollectionListRequest{})
+		return err
+	})
 
 	if err != nil {
 		return err
diff --git a/weed/shell/command_volume_list.go b/weed/shell/command_volume_list.go
index 971e18f10..52ac4865a 100644
--- a/weed/shell/command_volume_list.go
+++ b/weed/shell/command_volume_list.go
@@ -22,16 +22,18 @@ func (c *commandVolumeList) Help() string {
 	return "# list all volumes"
 }
 
-func (c *commandVolumeList) Do(args []string, commandEnv *commandEnv, writer io.Writer) error {
-
-	resp, err := commandEnv.masterClient.VolumeList(context.Background())
+func (c *commandVolumeList) Do(args []string, commandEnv *commandEnv, writer io.Writer) (err error) {
 
+	var resp *master_pb.VolumeListResponse
+	err = commandEnv.masterClient.WithClient(context.Background(), func(ctx context.Context, client master_pb.SeaweedClient) error {
+		resp, err = client.VolumeList(ctx, &master_pb.VolumeListRequest{})
+		return err
+	})
 	if err != nil {
 		return err
 	}
 
 	writeTopologyInfo(writer, resp.TopologyInfo)
-
 	return nil
 }
 
diff --git a/weed/wdclient/masterclient.go b/weed/wdclient/masterclient.go
index b3b277c74..5f147e594 100644
--- a/weed/wdclient/masterclient.go
+++ b/weed/wdclient/masterclient.go
@@ -116,3 +116,9 @@ func withMasterClient(ctx context.Context, master string, grpcDialOption grpc.Di
 
 	return fn(ctx, client)
 }
+
+func (mc *MasterClient) WithClient(ctx context.Context, fn func(ctx context.Context, client master_pb.SeaweedClient) error) error {
+	return withMasterClient(ctx, mc.currentMaster, mc.grpcDialOption, func(ctx context.Context, client master_pb.SeaweedClient) error {
+		return fn(ctx, client)
+	})
+}
diff --git a/weed/wdclient/masterclient_collection.go b/weed/wdclient/masterclient_collection.go
deleted file mode 100644
index 1a9215a7e..000000000
--- a/weed/wdclient/masterclient_collection.go
+++ /dev/null
@@ -1,31 +0,0 @@
-package wdclient
-
-import (
-	"context"
-	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
-)
-
-func (mc *MasterClient) CollectionDelete(ctx context.Context, collection string) error {
-	return withMasterClient(ctx, mc.currentMaster, mc.grpcDialOption, func(ctx context.Context, client master_pb.SeaweedClient) error {
-		_, err := client.CollectionDelete(ctx, &master_pb.CollectionDeleteRequest{
-			Name: collection,
-		})
-		return err
-	})
-}
-
-func (mc *MasterClient) CollectionList(ctx context.Context) (resp *master_pb.CollectionListResponse, err error) {
-	err = withMasterClient(ctx, mc.currentMaster, mc.grpcDialOption, func(ctx context.Context, client master_pb.SeaweedClient) error {
-		resp, err = client.CollectionList(ctx, &master_pb.CollectionListRequest{})
-		return err
-	})
-	return
-}
-
-func (mc *MasterClient) VolumeList(ctx context.Context) (resp *master_pb.VolumeListResponse, err error) {
-	err = withMasterClient(ctx, mc.currentMaster, mc.grpcDialOption, func(ctx context.Context, client master_pb.SeaweedClient) error {
-		resp, err = client.VolumeList(ctx, &master_pb.VolumeListRequest{})
-		return err
-	})
-	return
-}