diff --git a/weed/command/filer_replication.go b/weed/command/filer_replication.go
index c62b01445..8d5c9d8cc 100644
--- a/weed/command/filer_replication.go
+++ b/weed/command/filer_replication.go
@@ -5,12 +5,12 @@ import (
 
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/replication"
-	"github.com/chrislusf/seaweedfs/weed/server"
-	"github.com/spf13/viper"
 	"github.com/chrislusf/seaweedfs/weed/replication/sink"
-	_ "github.com/chrislusf/seaweedfs/weed/replication/sink/s3sink"
 	_ "github.com/chrislusf/seaweedfs/weed/replication/sink/filersink"
 	_ "github.com/chrislusf/seaweedfs/weed/replication/sink/gcssink"
+	_ "github.com/chrislusf/seaweedfs/weed/replication/sink/s3sink"
+	"github.com/chrislusf/seaweedfs/weed/server"
+	"github.com/spf13/viper"
 )
 
 func init() {
diff --git a/weed/command/volume.go b/weed/command/volume.go
index df8d842dc..e8c3f4a3c 100644
--- a/weed/command/volume.go
+++ b/weed/command/volume.go
@@ -1,17 +1,18 @@
 package command
 
 import (
+	"net/http"
 	"os"
 	"runtime"
+	"runtime/pprof"
 	"strconv"
 	"strings"
-	"github.com/chrislusf/seaweedfs/weed/glog"
-	"github.com/chrislusf/seaweedfs/weed/util"
-	"net/http"
-	"github.com/chrislusf/seaweedfs/weed/storage"
-	"github.com/chrislusf/seaweedfs/weed/server"
 	"time"
-	"runtime/pprof"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/server"
+	"github.com/chrislusf/seaweedfs/weed/storage"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )
 
 var (
diff --git a/weed/filesys/dir.go b/weed/filesys/dir.go
index 95afbf265..d8b0847d3 100644
--- a/weed/filesys/dir.go
+++ b/weed/filesys/dir.go
@@ -66,7 +66,7 @@ func (dir *Dir) Attr(context context.Context, attr *fuse.Attr) error {
 			return err
 		}
 
-		if resp.Entry!=nil {
+		if resp.Entry != nil {
 			dir.attributes = resp.Entry.Attributes
 		}
 
diff --git a/weed/operation/delete_content.go b/weed/operation/delete_content.go
index d2a0c4070..b77718846 100644
--- a/weed/operation/delete_content.go
+++ b/weed/operation/delete_content.go
@@ -10,9 +10,9 @@ import (
 
 	"net/http"
 
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/security"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/chrislusf/seaweedfs/weed/glog"
 )
 
 type DeleteResult struct {
diff --git a/weed/replication/notification_kafka.go b/weed/replication/notification_kafka.go
index 87f28f738..3bf917376 100644
--- a/weed/replication/notification_kafka.go
+++ b/weed/replication/notification_kafka.go
@@ -1,17 +1,17 @@
 package replication
 
 import (
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
+	"sync"
+	"time"
 
 	"github.com/Shopify/sarama"
 	"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"
-	"io/ioutil"
-	"encoding/json"
-	"sync"
-	"time"
 )
 
 func init() {
diff --git a/weed/replication/replicator.go b/weed/replication/replicator.go
index ba9898915..208e0894a 100644
--- a/weed/replication/replicator.go
+++ b/weed/replication/replicator.go
@@ -4,11 +4,11 @@ import (
 	"path/filepath"
 	"strings"
 
+	"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"
+	"github.com/chrislusf/seaweedfs/weed/replication/source"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/chrislusf/seaweedfs/weed/glog"
 )
 
 type Replicator struct {
diff --git a/weed/replication/sink/azuresink/azure_sink.go b/weed/replication/sink/azuresink/azure_sink.go
index 556dc4a6a..0639ef4ba 100644
--- a/weed/replication/sink/azuresink/azure_sink.go
+++ b/weed/replication/sink/azuresink/azure_sink.go
@@ -1,17 +1,17 @@
 package azuresink
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"net/url"
-	"bytes"
 
+	"github.com/Azure/azure-storage-blob-go/2016-05-31/azblob"
+	"github.com/chrislusf/seaweedfs/weed/filer2"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/replication/sink"
 	"github.com/chrislusf/seaweedfs/weed/replication/source"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/chrislusf/seaweedfs/weed/filer2"
-	"github.com/chrislusf/seaweedfs/weed/replication/sink"
-	"github.com/Azure/azure-storage-blob-go/2016-05-31/azblob"
 )
 
 type AzureSink struct {
@@ -46,7 +46,7 @@ func (g *AzureSink) SetSourceFiler(s *source.FilerSource) {
 	g.filerSource = s
 }
 
-func (g *AzureSink) initialize(accountName, accountKey, container, dir string) (error) {
+func (g *AzureSink) initialize(accountName, accountKey, container, dir string) error {
 	g.container = container
 	g.dir = dir
 
diff --git a/weed/replication/sink/filersink/filer_sink.go b/weed/replication/sink/filersink/filer_sink.go
index d526da1c9..e2974511a 100644
--- a/weed/replication/sink/filersink/filer_sink.go
+++ b/weed/replication/sink/filersink/filer_sink.go
@@ -7,9 +7,9 @@ import (
 	"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"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/chrislusf/seaweedfs/weed/replication/sink"
 )
 
 type FilerSink struct {
@@ -22,7 +22,7 @@ type FilerSink struct {
 	dataCenter  string
 }
 
-func init(){
+func init() {
 	sink.Sinks = append(sink.Sinks, &FilerSink{})
 }
 
diff --git a/weed/replication/sink/gcssink/gcs_sink.go b/weed/replication/sink/gcssink/gcs_sink.go
index 55012ecc7..ae7751c61 100644
--- a/weed/replication/sink/gcssink/gcs_sink.go
+++ b/weed/replication/sink/gcssink/gcs_sink.go
@@ -7,11 +7,11 @@ import (
 	"os"
 
 	"cloud.google.com/go/storage"
+	"github.com/chrislusf/seaweedfs/weed/filer2"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/replication/sink"
 	"github.com/chrislusf/seaweedfs/weed/replication/source"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/chrislusf/seaweedfs/weed/filer2"
-	"github.com/chrislusf/seaweedfs/weed/replication/sink"
 	"google.golang.org/api/option"
 )
 
@@ -46,7 +46,7 @@ func (g *GcsSink) SetSourceFiler(s *source.FilerSource) {
 	g.filerSource = s
 }
 
-func (g *GcsSink) initialize(google_application_credentials, bucketName, dir string) (error) {
+func (g *GcsSink) initialize(google_application_credentials, bucketName, dir string) error {
 	g.bucket = bucketName
 	g.dir = dir
 
diff --git a/weed/replication/sink/s3sink/s3_sink.go b/weed/replication/sink/s3sink/s3_sink.go
index ad41a0e99..b9caa839b 100644
--- a/weed/replication/sink/s3sink/s3_sink.go
+++ b/weed/replication/sink/s3sink/s3_sink.go
@@ -4,16 +4,16 @@ import (
 	"fmt"
 	"sync"
 
-	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
-	"github.com/chrislusf/seaweedfs/weed/replication/source"
-	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/aws/aws-sdk-go/service/s3/s3iface"
-	"github.com/aws/aws-sdk-go/service/s3"
-	"github.com/aws/aws-sdk-go/aws/session"
-	"github.com/chrislusf/seaweedfs/weed/filer2"
-	"github.com/chrislusf/seaweedfs/weed/replication/sink"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/s3"
+	"github.com/aws/aws-sdk-go/service/s3/s3iface"
+	"github.com/chrislusf/seaweedfs/weed/filer2"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/replication/sink"
+	"github.com/chrislusf/seaweedfs/weed/replication/source"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )
 
 type S3Sink struct {
@@ -50,7 +50,7 @@ func (s3sink *S3Sink) SetSourceFiler(s *source.FilerSource) {
 	s3sink.filerSource = s
 }
 
-func (s3sink *S3Sink) initialize(awsAccessKeyId, aswSecretAccessKey, region, bucket, dir string) (error) {
+func (s3sink *S3Sink) initialize(awsAccessKeyId, aswSecretAccessKey, region, bucket, dir string) error {
 	s3sink.region = region
 	s3sink.bucket = bucket
 	s3sink.dir = dir
diff --git a/weed/replication/sink/s3sink/s3_write.go b/weed/replication/sink/s3sink/s3_write.go
index df73e34a7..8ff722e67 100644
--- a/weed/replication/sink/s3sink/s3_write.go
+++ b/weed/replication/sink/s3sink/s3_write.go
@@ -1,16 +1,17 @@
 package S3Sink
 
 import (
-	"github.com/aws/aws-sdk-go/service/s3"
-	"github.com/aws/aws-sdk-go/aws"
-	"github.com/chrislusf/seaweedfs/weed/glog"
-	"github.com/aws/aws-sdk-go/aws/awserr"
+	"bytes"
 	"fmt"
 	"io"
-	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	"github.com/aws/aws-sdk-go/service/s3"
 	"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/util"
-	"bytes"
 )
 
 func (s3sink *S3Sink) deleteObject(key string) error {