diff --git a/weed/command/filer_replication.go b/weed/command/filer_replication.go
index 3ae4f1e2f..4780e9a3b 100644
--- a/weed/command/filer_replication.go
+++ b/weed/command/filer_replication.go
@@ -36,6 +36,7 @@ var cmdFilerReplicate = &Command{
 func runFilerReplicate(cmd *Command, args []string) bool {
 
 	weed_server.LoadConfiguration("replication", true)
+	weed_server.LoadConfiguration("notification", true)
 	config := viper.GetViper()
 
 	var notificationInput sub.NotificationInput
@@ -54,7 +55,8 @@ func runFilerReplicate(cmd *Command, args []string) bool {
 	}
 
 	if notificationInput == nil {
-		println("Please follow 'weed scaffold -config=repliaction' to see example notification configurations.")
+		println("No notification is defined in notification.toml file.")
+		println("Please follow 'weed scaffold -config=notification' to see example notification configurations.")
 		return true
 	}
 
@@ -85,7 +87,7 @@ func runFilerReplicate(cmd *Command, args []string) bool {
 	}
 
 	if dataSink == nil {
-		println("no data sink configured:")
+		println("no data sink configured in replication.toml:")
 		for _, sk := range sink.Sinks {
 			println("    " + sk.GetName())
 		}
diff --git a/weed/command/scaffold.go b/weed/command/scaffold.go
index cc6e5d6ef..4d836d9bc 100644
--- a/weed/command/scaffold.go
+++ b/weed/command/scaffold.go
@@ -19,7 +19,7 @@ var cmdScaffold = &Command{
 
 var (
 	outputPath = cmdScaffold.Flag.String("output", "", "if not empty, save the configuration file to this directory")
-	config     = cmdScaffold.Flag.String("config", "filer", "[filer|replication] the configuration file to generate")
+	config     = cmdScaffold.Flag.String("config", "filer", "[filer|notification|replication] the configuration file to generate")
 )
 
 func runScaffold(cmd *Command, args []string) bool {
@@ -28,6 +28,8 @@ func runScaffold(cmd *Command, args []string) bool {
 	switch *config {
 	case "filer":
 		content = FILER_TOML_EXAMPLE
+	case "notification":
+		content = NOTIFICATION_TOML_EXAMPLE
 	case "replication":
 		content = REPLICATION_TOML_EXAMPLE
 	}
@@ -37,7 +39,7 @@ func runScaffold(cmd *Command, args []string) bool {
 	}
 
 	if *outputPath != "" {
-		ioutil.WriteFile(filepath.Join(*outputPath, *config+".toml"), []byte(content), 0x755)
+		ioutil.WriteFile(filepath.Join(*outputPath, *config+".toml"), []byte(content), 0644)
 	} else {
 		println(content)
 	}
@@ -131,20 +133,34 @@ addresses = [
     "localhost:30006",
 ]
 
+`
+
+	NOTIFICATION_TOML_EXAMPLE = `
+# A sample TOML config file for SeaweedFS filer store
+# Used by both "weed filer" or "weed server -filer" and "weed filer.replicate"
+# Put this file to one of the location, with descending priority
+#    ./notification.toml
+#    $HOME/.seaweedfs/notification.toml
+#    /etc/seaweedfs/notification.toml
 
 ####################################################
 # notification
-# sends filer updates for each file to an external message queue
+# send and receive filer updates for each file to an external message queue
 ####################################################
 [notification.log]
+# this is only for debugging perpose and does not work with "weed filer.replicate"
 enabled = false
 
+
 [notification.kafka]
 enabled = false
 hosts = [
   "localhost:9092"
 ]
 topic = "seaweedfs_filer"
+offsetFile = "./last.offset"
+offsetSaveIntervalSeconds = 10
+
 
 [notification.aws_sqs]
 # experimental, let me know if it works
@@ -154,7 +170,16 @@ aws_secret_access_key = ""        # if empty, loads from the shared credentials
 region = "us-east-2"
 sqs_queue_name = "my_filer_queue" # an existing queue name
 
+
+[notification.google_pub_sub]
+# read credentials doc at https://cloud.google.com/docs/authentication/getting-started
+enabled = false
+google_application_credentials = "/path/to/x.json" # path to json credential file
+project_id = ""                       # an existing project id
+topic = "seaweedfs_filer_topic"       # a topic, auto created if does not exists
+
 `
+
 	REPLICATION_TOML_EXAMPLE = `
 # A sample TOML config file for replicating SeaweedFS filer
 # Used with "weed filer.replicate"
@@ -168,22 +193,6 @@ enabled = true
 grpcAddress = "localhost:18888"
 directory = "/buckets"    # all files under this directory tree are replicated
 
-[notification.kafka]
-enabled = false
-hosts = [
-  "localhost:9092"
-]
-topic = "seaweedfs_filer1_to_filer2"
-offsetFile = "./last.offset"
-offsetSaveIntervalSeconds = 10
-
-[notification.aws_sqs]
-enabled = false
-aws_access_key_id     = ""        # if empty, loads from the shared credentials file (~/.aws/credentials).
-aws_secret_access_key = ""        # if empty, loads from the shared credentials file (~/.aws/credentials).
-region = "us-east-2"
-sqs_queue_name = "my_filer_queue" # an existing queue name
-
 [sink.filer]
 enabled = false
 grpcAddress = "localhost:18888"
diff --git a/weed/notification/configuration.go b/weed/notification/configuration.go
index e0ba61d58..68c31af77 100644
--- a/weed/notification/configuration.go
+++ b/weed/notification/configuration.go
@@ -35,7 +35,7 @@ func LoadConfiguration(config *viper.Viper) {
 					store.GetName(), err)
 			}
 			Queue = store
-			glog.V(0).Infof("Configure message queue for %s", store.GetName())
+			glog.V(0).Infof("Configure notification message queue for %s", store.GetName())
 			return
 		}
 	}
diff --git a/weed/notification/google_pub_sub/google_pub_sub.go b/weed/notification/google_pub_sub/google_pub_sub.go
new file mode 100644
index 000000000..419fb26a4
--- /dev/null
+++ b/weed/notification/google_pub_sub/google_pub_sub.go
@@ -0,0 +1,89 @@
+package google_pub_sub
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/notification"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/api/option"
+	"context"
+	"cloud.google.com/go/pubsub"
+)
+
+func init() {
+	notification.MessageQueues = append(notification.MessageQueues, &GooglePubSub{})
+}
+
+type GooglePubSub struct {
+	topic *pubsub.Topic
+}
+
+func (k *GooglePubSub) GetName() string {
+	return "google_pub_sub"
+}
+
+func (k *GooglePubSub) Initialize(configuration util.Configuration) (err error) {
+	glog.V(0).Infof("notification.google_pub_sub.project_id: %v", configuration.GetString("project_id"))
+	glog.V(0).Infof("notification.google_pub_sub.topic: %v", configuration.GetString("topic"))
+	return k.initialize(
+		configuration.GetString("google_application_credentials"),
+		configuration.GetString("project_id"),
+		configuration.GetString("topic"),
+	)
+}
+
+func (k *GooglePubSub) initialize(google_application_credentials, projectId, topicName string) (err error) {
+
+	ctx := context.Background()
+	// Creates a client.
+	if google_application_credentials == "" {
+		var found bool
+		google_application_credentials, found = os.LookupEnv("GOOGLE_APPLICATION_CREDENTIALS")
+		if !found {
+			glog.Fatalf("need to specific GOOGLE_APPLICATION_CREDENTIALS env variable or google_application_credentials in filer.toml")
+		}
+	}
+
+	client, err := pubsub.NewClient(ctx, projectId, option.WithCredentialsFile(google_application_credentials))
+	if err != nil {
+		glog.Fatalf("Failed to create client: %v", err)
+	}
+
+	k.topic = client.Topic(topicName)
+	if exists, err := k.topic.Exists(ctx); err == nil {
+		if !exists {
+			k.topic, err = client.CreateTopic(ctx, topicName)
+			if err != nil {
+				glog.Fatalf("Failed to create topic %s: %v", topicName, err)
+			}
+		}
+	} else {
+		glog.Fatalf("Failed to check topic %s: %v", topicName, err)
+	}
+
+	return nil
+}
+
+func (k *GooglePubSub) SendMessage(key string, message proto.Message) (err error) {
+
+	bytes, err := proto.Marshal(message)
+	if err != nil {
+		return
+	}
+
+	ctx := context.Background()
+	result := k.topic.Publish(ctx, &pubsub.Message{
+		Data:       bytes,
+		Attributes: map[string]string{"key": key},
+	})
+
+	_, err = result.Get(ctx)
+	if err != nil {
+		return fmt.Errorf("send message to google pub sub %s: %v", k.topic.String(), err)
+	}
+
+	return nil
+}
diff --git a/weed/replication/sink/gcssink/gcs_sink.go b/weed/replication/sink/gcssink/gcs_sink.go
index ae7751c61..c1beefc33 100644
--- a/weed/replication/sink/gcssink/gcs_sink.go
+++ b/weed/replication/sink/gcssink/gcs_sink.go
@@ -3,11 +3,11 @@ package gcssink
 import (
 	"context"
 	"fmt"
-	"log"
 	"os"
 
 	"cloud.google.com/go/storage"
 	"github.com/chrislusf/seaweedfs/weed/filer2"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/replication/sink"
 	"github.com/chrislusf/seaweedfs/weed/replication/source"
@@ -56,12 +56,12 @@ func (g *GcsSink) initialize(google_application_credentials, bucketName, dir str
 		var found bool
 		google_application_credentials, found = os.LookupEnv("GOOGLE_APPLICATION_CREDENTIALS")
 		if !found {
-			log.Fatalf("need to specific GOOGLE_APPLICATION_CREDENTIALS env variable or google_application_credentials in replication.toml")
+			glog.Fatalf("need to specific GOOGLE_APPLICATION_CREDENTIALS env variable or google_application_credentials in replication.toml")
 		}
 	}
 	client, err := storage.NewClient(ctx, option.WithCredentialsFile(google_application_credentials))
 	if err != nil {
-		log.Fatalf("Failed to create client: %v", err)
+		glog.Fatalf("Failed to create client: %v", err)
 	}
 
 	g.client = client
diff --git a/weed/replication/sub/notification_google_pub_sub.go b/weed/replication/sub/notification_google_pub_sub.go
new file mode 100644
index 000000000..49b0c56de
--- /dev/null
+++ b/weed/replication/sub/notification_google_pub_sub.go
@@ -0,0 +1,109 @@
+package sub
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/golang/protobuf/proto"
+	"cloud.google.com/go/pubsub"
+	"google.golang.org/api/option"
+)
+
+func init() {
+	NotificationInputs = append(NotificationInputs, &GooglePubSubInput{})
+}
+
+type GooglePubSubInput struct {
+	sub         *pubsub.Subscription
+	topicName   string
+	messageChan chan *pubsub.Message
+}
+
+func (k *GooglePubSubInput) GetName() string {
+	return "google_pub_sub"
+}
+
+func (k *GooglePubSubInput) Initialize(configuration util.Configuration) error {
+	glog.V(0).Infof("notification.google_pub_sub.project_id: %v", configuration.GetString("project_id"))
+	glog.V(0).Infof("notification.google_pub_sub.topic: %v", configuration.GetString("topic"))
+	return k.initialize(
+		configuration.GetString("google_application_credentials"),
+		configuration.GetString("project_id"),
+		configuration.GetString("topic"),
+	)
+}
+
+func (k *GooglePubSubInput) initialize(google_application_credentials, projectId, topicName string) (err error) {
+
+	ctx := context.Background()
+	// Creates a client.
+	if google_application_credentials == "" {
+		var found bool
+		google_application_credentials, found = os.LookupEnv("GOOGLE_APPLICATION_CREDENTIALS")
+		if !found {
+			glog.Fatalf("need to specific GOOGLE_APPLICATION_CREDENTIALS env variable or google_application_credentials in filer.toml")
+		}
+	}
+
+	client, err := pubsub.NewClient(ctx, projectId, option.WithCredentialsFile(google_application_credentials))
+	if err != nil {
+		glog.Fatalf("Failed to create client: %v", err)
+	}
+
+	k.topicName = topicName
+	topic := client.Topic(topicName)
+	if exists, err := topic.Exists(ctx); err == nil {
+		if !exists {
+			topic, err = client.CreateTopic(ctx, topicName)
+			if err != nil {
+				glog.Fatalf("Failed to create topic %s: %v", topicName, err)
+			}
+		}
+	} else {
+		glog.Fatalf("Failed to check topic %s: %v", topicName, err)
+	}
+
+	subscriptionName := "seaweedfs_sub"
+
+	k.sub = client.Subscription(subscriptionName)
+	if exists, err := k.sub.Exists(ctx); err == nil {
+		if !exists {
+			k.sub, err = client.CreateSubscription(ctx, subscriptionName, pubsub.SubscriptionConfig{Topic: topic})
+			if err != nil {
+				glog.Fatalf("Failed to create subscription %s: %v", subscriptionName, err)
+			}
+		}
+	} else {
+		glog.Fatalf("Failed to check subscription %s: %v", topicName, err)
+	}
+
+	k.messageChan = make(chan *pubsub.Message, 1)
+
+	go k.sub.Receive(ctx, func(ctx context.Context, m *pubsub.Message) {
+		k.messageChan <- m
+		m.Ack()
+	})
+
+	return err
+}
+
+func (k *GooglePubSubInput) ReceiveMessage() (key string, message *filer_pb.EventNotification, err error) {
+
+	m := <-k.messageChan
+
+	// process the message
+	key = m.Attributes["key"]
+	message = &filer_pb.EventNotification{}
+	err = proto.Unmarshal(m.Data, message)
+
+	if err != nil {
+		err = fmt.Errorf("unmarshal message from google pubsub %s: %v", k.topicName, err)
+		return
+	}
+
+	return
+}
diff --git a/weed/server/filer_server.go b/weed/server/filer_server.go
index 65fa26987..f4100e5b2 100644
--- a/weed/server/filer_server.go
+++ b/weed/server/filer_server.go
@@ -14,6 +14,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/notification"
 	_ "github.com/chrislusf/seaweedfs/weed/notification/kafka"
 	_ "github.com/chrislusf/seaweedfs/weed/notification/aws_sqs"
+	_ "github.com/chrislusf/seaweedfs/weed/notification/google_pub_sub"
 	_ "github.com/chrislusf/seaweedfs/weed/notification/log"
 	"github.com/chrislusf/seaweedfs/weed/security"
 	"github.com/spf13/viper"
@@ -52,6 +53,7 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 	go fs.filer.KeepConnectedToMaster()
 
 	LoadConfiguration("filer", true)
+	LoadConfiguration("notification", false)
 	v := viper.GetViper()
 
 	fs.filer.LoadConfiguration(v)
@@ -81,15 +83,15 @@ func LoadConfiguration(configFileName string, required bool) {
 
 	glog.V(0).Infof("Reading %s.toml from %s", configFileName, viper.ConfigFileUsed())
 
-	if err := viper.ReadInConfig(); err != nil { // Handle errors reading the config file
+	if err := viper.MergeInConfig(); err != nil { // Handle errors reading the config file
 		glog.V(0).Infof("Reading %s: %v", viper.ConfigFileUsed(), err)
 		if required {
-			glog.Errorf("Failed to load %s.toml file from current directory, or $HOME/.seaweedfs/, or /etc/seaweedfs/"+
+			glog.Fatalf("Failed to load %s.toml file from current directory, or $HOME/.seaweedfs/, or /etc/seaweedfs/"+
 				"\n\nPlease follow this example and add a filer.toml file to "+
 				"current directory, or $HOME/.seaweedfs/, or /etc/seaweedfs/:\n"+
 				"    https://github.com/chrislusf/seaweedfs/blob/master/weed/%s.toml\n"+
-				"\n\nOr use this command to generate the default toml file\n"+
-				"    weed scaffold -config=%s -output=.\n",
+				"\nOr use this command to generate the default toml file\n"+
+				"    weed scaffold -config=%s -output=.\n\n\n",
 				configFileName, configFileName, configFileName)
 		}
 	}