diff --git a/weed/command/master.go b/weed/command/master.go
index 8e10d25a2..3b1986536 100644
--- a/weed/command/master.go
+++ b/weed/command/master.go
@@ -49,21 +49,22 @@ type MasterOptions struct {
 	volumePreallocate          *bool
 	maxParallelVacuumPerServer *int
 	// pulseSeconds       *int
-	defaultReplication *string
-	garbageThreshold   *float64
-	whiteList          *string
-	disableHttp        *bool
-	metricsAddress     *string
-	metricsIntervalSec *int
-	raftResumeState    *bool
-	metricsHttpPort    *int
-	metricsHttpIp      *string
-	heartbeatInterval  *time.Duration
-	electionTimeout    *time.Duration
-	raftHashicorp      *bool
-	raftBootstrap      *bool
-	telemetryUrl       *string
-	telemetryEnabled   *bool
+	defaultReplication     *string
+	garbageThreshold       *float64
+	whiteList              *string
+	disableHttp            *bool
+	metricsAddress         *string
+	metricsIntervalSec     *int
+	raftResumeState        *bool
+	metricsHttpPort        *int
+	metricsHttpIp          *string
+	heartbeatInterval      *time.Duration
+	electionTimeout        *time.Duration
+	raftHashicorp          *bool
+	raftBootstrap          *bool
+	telemetryUrl           *string
+	telemetryEnabled       *bool
+	intervalToCollectStats *time.Duration
 }
 
 func init() {
@@ -93,6 +94,7 @@ func init() {
 	m.raftBootstrap = cmdMaster.Flag.Bool("raftBootstrap", false, "Whether to bootstrap the Raft cluster")
 	m.telemetryUrl = cmdMaster.Flag.String("telemetry.url", "https://telemetry.seaweedfs.com/api/collect", "telemetry server URL to send usage statistics")
 	m.telemetryEnabled = cmdMaster.Flag.Bool("telemetry", false, "enable telemetry reporting")
+	m.intervalToCollectStats = cmdMaster.Flag.Duration("intervalToCollectStats", time.Second*120, "interval to collect s3 stats")
 }
 
 var cmdMaster = &Command{
@@ -229,6 +231,8 @@ func startMaster(masterOption MasterOptions, masterWhiteList []string) {
 	}
 	go grpcS.Serve(grpcL)
 
+	rootCtx, rootCancel := context.WithCancel(context.Background())
+
 	timeSleep := 1500 * time.Millisecond
 	if !*masterOption.raftHashicorp {
 		go func() {
@@ -243,7 +247,8 @@ func startMaster(masterOption MasterOptions, masterWhiteList []string) {
 		}()
 	}
 
-	go ms.MasterClient.KeepConnectedToMaster(context.Background())
+	go ms.MasterClient.KeepConnectedToMaster(rootCtx)
+	statsShutdown := weed_server.CollectCollectionsStats(rootCtx, ms, *masterOption.intervalToCollectStats)
 
 	// start http server
 	var (
@@ -283,6 +288,15 @@ func startMaster(masterOption MasterOptions, masterWhiteList []string) {
 
 	grace.OnInterrupt(ms.Shutdown)
 	grace.OnInterrupt(grpcS.Stop)
+	grace.OnInterrupt(func() {
+		rootCancel()
+
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+		if err := statsShutdown(ctx); err != nil {
+			glog.Errorf("graceful shutdown of collections stats: %v", err)
+		}
+	})
 	grace.OnReload(func() {
 		if ms.Topo.HashicorpRaft != nil && ms.Topo.HashicorpRaft.State() == hashicorpRaft.Leader {
 			ms.Topo.HashicorpRaft.LeadershipTransfer()
diff --git a/weed/command/server.go b/weed/command/server.go
index f2e2e1b58..78274d95a 100644
--- a/weed/command/server.go
+++ b/weed/command/server.go
@@ -109,6 +109,7 @@ func init() {
 	masterOptions.electionTimeout = cmdServer.Flag.Duration("master.electionTimeout", 10*time.Second, "election timeout of master servers")
 	masterOptions.telemetryUrl = cmdServer.Flag.String("master.telemetry.url", "https://telemetry.seaweedfs.com/api/collect", "telemetry server URL to send usage statistics")
 	masterOptions.telemetryEnabled = cmdServer.Flag.Bool("master.telemetry", false, "enable telemetry reporting")
+	masterOptions.intervalToCollectStats = cmdServer.Flag.Duration("master.intervalToCollectStats", time.Second*120, "interval to collect s3 stats")
 
 	filerOptions.filerGroup = cmdServer.Flag.String("filer.filerGroup", "", "share metadata with other filers in the same filerGroup")
 	filerOptions.collection = cmdServer.Flag.String("filer.collection", "", "all data will be stored in this collection")
diff --git a/weed/server/master_server.go b/weed/server/master_server.go
index 10b54d58f..ff2887ede 100644
--- a/weed/server/master_server.go
+++ b/weed/server/master_server.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/seaweedfs/seaweedfs/weed/stats"
+	"github.com/seaweedfs/seaweedfs/weed/storage/super_block"
 	"github.com/seaweedfs/seaweedfs/weed/telemetry"
 
 	"github.com/seaweedfs/seaweedfs/weed/cluster"
@@ -34,6 +35,7 @@ import (
 	util_http "github.com/seaweedfs/seaweedfs/weed/util/http"
 	"github.com/seaweedfs/seaweedfs/weed/util/version"
 	"github.com/seaweedfs/seaweedfs/weed/wdclient"
+	"math"
 )
 
 const (
@@ -437,3 +439,71 @@ func (ms *MasterServer) Reload() {
 		util.StringSplit(v.GetString("guard.white_list"), ",")...),
 	)
 }
+
+func CollectCollectionsStats(parent context.Context, ms *MasterServer, interval time.Duration) (shutdown func(ctx context.Context) error) {
+	ctx, cancel := context.WithCancel(parent)
+	done := make(chan struct{})
+
+	go func() {
+		defer close(done)
+		ticker := time.NewTicker(interval)
+		defer ticker.Stop()
+
+		req := &master_pb.VolumeListRequest{}
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+				volumeList, err := ms.VolumeList(ctx, req)
+				if err != nil {
+					glog.Errorf("collect volume list: %v", err)
+					continue
+				}
+				if volumeList == nil || volumeList.TopologyInfo == nil {
+					continue
+				}
+
+				collectionInfos := make(map[string]*shell.CollectionInfo)
+				for _, dc := range volumeList.TopologyInfo.DataCenterInfos {
+					for _, r := range dc.RackInfos {
+						for _, dn := range r.DataNodeInfos {
+							for _, diskInfo := range dn.DiskInfos {
+								for _, vif := range diskInfo.VolumeInfos {
+									c := vif.Collection
+									cif := collectionInfos[c]
+									if cif == nil {
+										cif = &shell.CollectionInfo{}
+										collectionInfos[c] = cif
+									}
+									replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(vif.ReplicaPlacement))
+									copyCount := float64(replicaPlacement.GetCopyCount())
+									cif.Size += float64(vif.Size) / copyCount
+									cif.DeleteCount += float64(vif.DeleteCount) / copyCount
+									cif.FileCount += float64(vif.FileCount) / copyCount
+									cif.DeletedByteCount += float64(vif.DeletedByteCount) / copyCount
+									cif.VolumeCount++
+								}
+							}
+						}
+					}
+				}
+
+				for bucket, v := range collectionInfos {
+					stats.S3BucketFileCount.WithLabelValues(bucket).Set(math.Round(v.FileCount - v.DeleteCount))
+					stats.S3BucketSize.WithLabelValues(bucket).Set(math.Round(v.Size - v.DeletedByteCount))
+				}
+			}
+		}
+	}()
+
+	return func(ctx context.Context) error {
+		cancel()
+		select {
+		case <-done:
+			return nil
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
diff --git a/weed/stats/metrics.go b/weed/stats/metrics.go
index 2723e253f..1af98b51f 100644
--- a/weed/stats/metrics.go
+++ b/weed/stats/metrics.go
@@ -382,6 +382,22 @@ var (
 			Name:      "uploaded_objects",
 			Help:      "Number of objects uploaded in each bucket.",
 		}, []string{"bucket"})
+
+	S3BucketFileCount = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: Namespace,
+			Subsystem: "s3",
+			Name:      "bucket_file_count",
+			Help:      "Number files in bucket",
+		}, []string{"bucket"})
+
+	S3BucketSize = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: Namespace,
+			Subsystem: "s3",
+			Name:      "bucket_size",
+			Help:      "Bucket size in bytes",
+		}, []string{"bucket"})
 )
 
 func init() {
@@ -433,6 +449,8 @@ func init() {
 	Gather.MustRegister(S3BucketTrafficSentBytesCounter)
 	Gather.MustRegister(S3DeletedObjectsCounter)
 	Gather.MustRegister(S3UploadedObjectsCounter)
+	Gather.MustRegister(S3BucketFileCount)
+	Gather.MustRegister(S3BucketSize)
 
 	go bucketMetricTTLControl()
 }