fetch bucket replication stats across peers in single call (#14956)

current implementation relied on recursively calling one bucket
at a time across all peers, this would be very slow and chatty
when there are 100's of buckets which would mean 100*peerCount
amount of network operations.

This PR attempts to reduce this entire call into `peerCount`
amount of network calls only. This functionality addresses also a
concern where the Prometheus metrics would significantly slow
down when one of the peers is offline.

cmd/bucket-replication-stats.go

@@ -135,6 +135,23 @@ func (r *ReplicationStats) GetInitialUsage(bucket string) BucketReplicationStats
 	return st.Clone()
 }
 
+// GetAll returns replication metrics for all buckets at once.
+func (r *ReplicationStats) GetAll() map[string]BucketReplicationStats {
+	if r == nil {
+		return map[string]BucketReplicationStats{}
+	}
+
+	r.RLock()
+	defer r.RUnlock()
+
+	bucketReplicationStats := make(map[string]BucketReplicationStats, len(r.Cache))
+	for k, v := range r.Cache {
+		bucketReplicationStats[k] = v.Clone()
+	}
+
+	return bucketReplicationStats
+}
+
 // Get replication metrics for a bucket from this node since this node came up.
 func (r *ReplicationStats) Get(bucket string) BucketReplicationStats {
 	if r == nil {

cmd/bucket-replication.go

@@ -1845,9 +1845,26 @@ func resyncTarget(oi ObjectInfo, arn string, resetID string, resetBeforeDate tim
 	return
 }
 
-// get the most current of in-memory replication stats  and data usage info from crawler.
-func getLatestReplicationStats(bucket string, u BucketUsageInfo) (s BucketReplicationStats) {
-	bucketStats := globalNotificationSys.GetClusterBucketStats(GlobalContext, bucket)
+func getAllLatestReplicationStats(bucketsUsage map[string]BucketUsageInfo) (bucketsReplicationStats map[string]BucketReplicationStats) {
+	peerBucketStatsList := globalNotificationSys.GetClusterAllBucketStats(GlobalContext)
+	bucketsReplicationStats = make(map[string]BucketReplicationStats, len(bucketsUsage))
+
+	for bucket, u := range bucketsUsage {
+		bucketStats := make([]BucketStats, len(peerBucketStatsList))
+		for i, peerBucketStats := range peerBucketStatsList {
+			bucketStat, ok := peerBucketStats[bucket]
+			if !ok {
+				continue
+			}
+			bucketStats[i] = bucketStat
+		}
+		bucketsReplicationStats[bucket] = calculateBucketReplicationStats(bucket, u, bucketStats)
+	}
+
+	return bucketsReplicationStats
+}
+
+func calculateBucketReplicationStats(bucket string, u BucketUsageInfo, bucketStats []BucketStats) (s BucketReplicationStats) {
 	// accumulate cluster bucket stats
 	stats := make(map[string]*BucketReplicationStat)
 	var totReplicaSize int64
@@ -1916,6 +1933,12 @@ func getLatestReplicationStats(bucket string, u BucketUsageInfo) (s BucketReplic
 	return s
 }
 
+// get the most current of in-memory replication stats  and data usage info from crawler.
+func getLatestReplicationStats(bucket string, u BucketUsageInfo) (s BucketReplicationStats) {
+	bucketStats := globalNotificationSys.GetClusterBucketStats(GlobalContext, bucket)
+	return calculateBucketReplicationStats(bucket, u, bucketStats)
+}
+
 const resyncTimeInterval = time.Minute * 10
 
 // periodicResyncMetaSave saves in-memory resync meta stats to disk in periodic intervals

cmd/bucket-stats.go

@@ -51,6 +51,9 @@ func (rl *ReplicationLatency) update(size int64, duration time.Duration) {
 	rl.UploadHistogram.Add(size, duration)
 }
 
+// BucketStatsMap captures bucket statistics for all buckets
+type BucketStatsMap map[string]BucketStats
+
 // BucketStats bucket statistics
 type BucketStats struct {
 	ReplicationStats BucketReplicationStats

cmd/bucket-stats_gen.go

@@ -792,6 +792,183 @@ func (z *BucketStats) Msgsize() (s int) {
 	return
 }
 
+// DecodeMsg implements msgp.Decodable
+func (z *BucketStatsMap) DecodeMsg(dc *msgp.Reader) (err error) {
+	var zb0003 uint32
+	zb0003, err = dc.ReadMapHeader()
+	if err != nil {
+		err = msgp.WrapError(err)
+		return
+	}
+	if (*z) == nil {
+		(*z) = make(BucketStatsMap, zb0003)
+	} else if len((*z)) > 0 {
+		for key := range *z {
+			delete((*z), key)
+		}
+	}
+	for zb0003 > 0 {
+		zb0003--
+		var zb0001 string
+		var zb0002 BucketStats
+		zb0001, err = dc.ReadString()
+		if err != nil {
+			err = msgp.WrapError(err)
+			return
+		}
+		var field []byte
+		_ = field
+		var zb0004 uint32
+		zb0004, err = dc.ReadMapHeader()
+		if err != nil {
+			err = msgp.WrapError(err, zb0001)
+			return
+		}
+		for zb0004 > 0 {
+			zb0004--
+			field, err = dc.ReadMapKeyPtr()
+			if err != nil {
+				err = msgp.WrapError(err, zb0001)
+				return
+			}
+			switch msgp.UnsafeString(field) {
+			case "ReplicationStats":
+				err = zb0002.ReplicationStats.DecodeMsg(dc)
+				if err != nil {
+					err = msgp.WrapError(err, zb0001, "ReplicationStats")
+					return
+				}
+			default:
+				err = dc.Skip()
+				if err != nil {
+					err = msgp.WrapError(err, zb0001)
+					return
+				}
+			}
+		}
+		(*z)[zb0001] = zb0002
+	}
+	return
+}
+
+// EncodeMsg implements msgp.Encodable
+func (z BucketStatsMap) EncodeMsg(en *msgp.Writer) (err error) {
+	err = en.WriteMapHeader(uint32(len(z)))
+	if err != nil {
+		err = msgp.WrapError(err)
+		return
+	}
+	for zb0005, zb0006 := range z {
+		err = en.WriteString(zb0005)
+		if err != nil {
+			err = msgp.WrapError(err)
+			return
+		}
+		// map header, size 1
+		// write "ReplicationStats"
+		err = en.Append(0x81, 0xb0, 0x52, 0x65, 0x70, 0x6c, 0x69, 0x63, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x53, 0x74, 0x61, 0x74, 0x73)
+		if err != nil {
+			return
+		}
+		err = zb0006.ReplicationStats.EncodeMsg(en)
+		if err != nil {
+			err = msgp.WrapError(err, zb0005, "ReplicationStats")
+			return
+		}
+	}
+	return
+}
+
+// MarshalMsg implements msgp.Marshaler
+func (z BucketStatsMap) MarshalMsg(b []byte) (o []byte, err error) {
+	o = msgp.Require(b, z.Msgsize())
+	o = msgp.AppendMapHeader(o, uint32(len(z)))
+	for zb0005, zb0006 := range z {
+		o = msgp.AppendString(o, zb0005)
+		// map header, size 1
+		// string "ReplicationStats"
+		o = append(o, 0x81, 0xb0, 0x52, 0x65, 0x70, 0x6c, 0x69, 0x63, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x53, 0x74, 0x61, 0x74, 0x73)
+		o, err = zb0006.ReplicationStats.MarshalMsg(o)
+		if err != nil {
+			err = msgp.WrapError(err, zb0005, "ReplicationStats")
+			return
+		}
+	}
+	return
+}
+
+// UnmarshalMsg implements msgp.Unmarshaler
+func (z *BucketStatsMap) UnmarshalMsg(bts []byte) (o []byte, err error) {
+	var zb0003 uint32
+	zb0003, bts, err = msgp.ReadMapHeaderBytes(bts)
+	if err != nil {
+		err = msgp.WrapError(err)
+		return
+	}
+	if (*z) == nil {
+		(*z) = make(BucketStatsMap, zb0003)
+	} else if len((*z)) > 0 {
+		for key := range *z {
+			delete((*z), key)
+		}
+	}
+	for zb0003 > 0 {
+		var zb0001 string
+		var zb0002 BucketStats
+		zb0003--
+		zb0001, bts, err = msgp.ReadStringBytes(bts)
+		if err != nil {
+			err = msgp.WrapError(err)
+			return
+		}
+		var field []byte
+		_ = field
+		var zb0004 uint32
+		zb0004, bts, err = msgp.ReadMapHeaderBytes(bts)
+		if err != nil {
+			err = msgp.WrapError(err, zb0001)
+			return
+		}
+		for zb0004 > 0 {
+			zb0004--
+			field, bts, err = msgp.ReadMapKeyZC(bts)
+			if err != nil {
+				err = msgp.WrapError(err, zb0001)
+				return
+			}
+			switch msgp.UnsafeString(field) {
+			case "ReplicationStats":
+				bts, err = zb0002.ReplicationStats.UnmarshalMsg(bts)
+				if err != nil {
+					err = msgp.WrapError(err, zb0001, "ReplicationStats")
+					return
+				}
+			default:
+				bts, err = msgp.Skip(bts)
+				if err != nil {
+					err = msgp.WrapError(err, zb0001)
+					return
+				}
+			}
+		}
+		(*z)[zb0001] = zb0002
+	}
+	o = bts
+	return
+}
+
+// Msgsize returns an upper bound estimate of the number of bytes occupied by the serialized message
+func (z BucketStatsMap) Msgsize() (s int) {
+	s = msgp.MapHeaderSize
+	if z != nil {
+		for zb0005, zb0006 := range z {
+			_ = zb0006
+			s += msgp.StringPrefixSize + len(zb0005) + 1 + 17 + zb0006.ReplicationStats.Msgsize()
+		}
+	}
+	return
+}
+
 // DecodeMsg implements msgp.Decodable
 func (z *ReplicationLatency) DecodeMsg(dc *msgp.Reader) (err error) {
 	var field []byte

cmd/bucket-stats_gen_test.go

@@ -348,6 +348,119 @@ func BenchmarkDecodeBucketStats(b *testing.B) {
 	}
 }
 
+func TestMarshalUnmarshalBucketStatsMap(t *testing.T) {
+	v := BucketStatsMap{}
+	bts, err := v.MarshalMsg(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	left, err := v.UnmarshalMsg(bts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) > 0 {
+		t.Errorf("%d bytes left over after UnmarshalMsg(): %q", len(left), left)
+	}
+
+	left, err = msgp.Skip(bts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) > 0 {
+		t.Errorf("%d bytes left over after Skip(): %q", len(left), left)
+	}
+}
+
+func BenchmarkMarshalMsgBucketStatsMap(b *testing.B) {
+	v := BucketStatsMap{}
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		v.MarshalMsg(nil)
+	}
+}
+
+func BenchmarkAppendMsgBucketStatsMap(b *testing.B) {
+	v := BucketStatsMap{}
+	bts := make([]byte, 0, v.Msgsize())
+	bts, _ = v.MarshalMsg(bts[0:0])
+	b.SetBytes(int64(len(bts)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bts, _ = v.MarshalMsg(bts[0:0])
+	}
+}
+
+func BenchmarkUnmarshalBucketStatsMap(b *testing.B) {
+	v := BucketStatsMap{}
+	bts, _ := v.MarshalMsg(nil)
+	b.ReportAllocs()
+	b.SetBytes(int64(len(bts)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := v.UnmarshalMsg(bts)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func TestEncodeDecodeBucketStatsMap(t *testing.T) {
+	v := BucketStatsMap{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+
+	m := v.Msgsize()
+	if buf.Len() > m {
+		t.Log("WARNING: TestEncodeDecodeBucketStatsMap Msgsize() is inaccurate")
+	}
+
+	vn := BucketStatsMap{}
+	err := msgp.Decode(&buf, &vn)
+	if err != nil {
+		t.Error(err)
+	}
+
+	buf.Reset()
+	msgp.Encode(&buf, &v)
+	err = msgp.NewReader(&buf).Skip()
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func BenchmarkEncodeBucketStatsMap(b *testing.B) {
+	v := BucketStatsMap{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+	b.SetBytes(int64(buf.Len()))
+	en := msgp.NewWriter(msgp.Nowhere)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		v.EncodeMsg(en)
+	}
+	en.Flush()
+}
+
+func BenchmarkDecodeBucketStatsMap(b *testing.B) {
+	v := BucketStatsMap{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+	b.SetBytes(int64(buf.Len()))
+	rd := msgp.NewEndlessReader(buf.Bytes(), b)
+	dc := msgp.NewReader(rd)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		err := v.DecodeMsg(dc)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
 func TestMarshalUnmarshalReplicationLatency(t *testing.T) {
 	v := ReplicationLatency{}
 	bts, err := v.MarshalMsg(nil)

cmd/metrics-v2.go

@@ -1604,8 +1604,9 @@ func getBucketUsageMetrics() *MetricsGroup {
 			Value:       float64(time.Since(dataUsageInfo.LastUpdate)),
 		})
 
+		bucketReplStats := getAllLatestReplicationStats(dataUsageInfo.BucketsUsage)
 		for bucket, usage := range dataUsageInfo.BucketsUsage {
-			stats := getLatestReplicationStats(bucket, usage)
+			stats := bucketReplStats[bucket]
 
 			quota, _ := globalBucketQuotaSys.Get(ctx, bucket)
 

cmd/notification.go

@@ -601,6 +601,44 @@ func (sys *NotificationSys) DeleteBucketMetadata(ctx context.Context, bucketName
 	}
 }
 
+// GetClusterAllBucketStats - returns bucket stats for all buckets from all remote peers.
+func (sys *NotificationSys) GetClusterAllBucketStats(ctx context.Context) []BucketStatsMap {
+	ng := WithNPeers(len(sys.peerClients))
+	replicationStats := make([]BucketStatsMap, len(sys.peerClients))
+	for index, client := range sys.peerClients {
+		index := index
+		client := client
+		ng.Go(ctx, func() error {
+			if client == nil {
+				return errPeerNotReachable
+			}
+			bsMap, err := client.GetAllBucketStats()
+			if err != nil {
+				return err
+			}
+			replicationStats[index] = bsMap
+			return nil
+		}, index, *client.host)
+	}
+	for _, nErr := range ng.Wait() {
+		reqInfo := (&logger.ReqInfo{}).AppendTags("peerAddress", nErr.Host.String())
+		if nErr.Err != nil {
+			logger.LogIf(logger.SetReqInfo(ctx, reqInfo), nErr.Err)
+		}
+	}
+
+	replicationStatsList := globalReplicationStats.GetAll()
+	bucketStatsMap := make(map[string]BucketStats, len(replicationStatsList))
+	for k, replicationStats := range replicationStatsList {
+		bucketStatsMap[k] = BucketStats{
+			ReplicationStats: replicationStats,
+		}
+	}
+
+	replicationStats = append(replicationStats, BucketStatsMap(bucketStatsMap))
+	return replicationStats
+}
+
 // GetClusterBucketStats - calls GetClusterBucketStats call on all peers for a cluster statistics view.
 func (sys *NotificationSys) GetClusterBucketStats(ctx context.Context, bucketName string) []BucketStats {
 	ng := WithNPeers(len(sys.peerClients))

cmd/peer-rest-client.go

@@ -510,6 +510,19 @@ func (client *peerRESTClient) GetBucketStats(bucket string) (BucketStats, error)
 	return bs, msgp.Decode(respBody, &bs)
 }
 
+// GetAllBucketStats - load replication stats for all buckets
+func (client *peerRESTClient) GetAllBucketStats() (BucketStatsMap, error) {
+	values := make(url.Values)
+	respBody, err := client.call(peerRESTMethodGetAllBucketStats, values, nil, -1)
+	if err != nil {
+		return nil, err
+	}
+
+	bsMap := BucketStatsMap{}
+	defer http.DrainBody(respBody)
+	return bsMap, msgp.Decode(respBody, &bsMap)
+}
+
 // LoadBucketMetadata - load bucket metadata
 func (client *peerRESTClient) LoadBucketMetadata(bucket string) error {
 	values := make(url.Values)

cmd/peer-rest-common.go

@@ -18,7 +18,7 @@
 package cmd
 
 const (
-	peerRESTVersion       = "v21" // Add netperf
+	peerRESTVersion       = "v22" // Add bulk GetBucketStats
 	peerRESTVersionPrefix = SlashSeparator + peerRESTVersion
 	peerRESTPrefix        = minioReservedBucketPath + "/peer"
 	peerRESTPath          = peerRESTPrefix + peerRESTVersionPrefix
@@ -41,6 +41,7 @@ const (
 	peerRESTMethodDeleteBucketMetadata        = "/deletebucketmetadata"
 	peerRESTMethodLoadBucketMetadata          = "/loadbucketmetadata"
 	peerRESTMethodGetBucketStats              = "/getbucketstats"
+	peerRESTMethodGetAllBucketStats           = "/getallbucketstats"
 	peerRESTMethodServerUpdate                = "/serverupdate"
 	peerRESTMethodSignalService               = "/signalservice"
 	peerRESTMethodBackgroundHealStatus        = "/backgroundhealstatus"

cmd/peer-rest-server.go

@@ -561,8 +561,26 @@ func (s *peerRESTServer) ReloadSiteReplicationConfigHandler(w http.ResponseWrite
 	logger.LogIf(r.Context(), globalSiteReplicationSys.Init(ctx, objAPI))
 }
 
+// GetAllBucketStatsHandler - fetches bucket replication stats for all buckets from this peer.
+func (s *peerRESTServer) GetAllBucketStatsHandler(w http.ResponseWriter, r *http.Request) {
+	if !s.IsValid(w, r) {
+		s.writeErrorResponse(w, errors.New("Invalid request"))
+		return
+	}
+
+	replicationStats := globalReplicationStats.GetAll()
+	bucketStatsMap := make(map[string]BucketStats, len(replicationStats))
+	for k, v := range replicationStats {
+		bucketStatsMap[k] = BucketStats{
+			ReplicationStats: v,
+		}
+	}
+
+	logger.LogIf(r.Context(), msgp.Encode(w, BucketStatsMap(bucketStatsMap)))
+}
+
 // GetBucketStatsHandler - fetches current in-memory bucket stats, currently only
-// returns BucketReplicationStatus
+// returns BucketStats, that currently includes ReplicationStats.
 func (s *peerRESTServer) GetBucketStatsHandler(w http.ResponseWriter, r *http.Request) {
 	if !s.IsValid(w, r) {
 		s.writeErrorResponse(w, errors.New("Invalid request"))
@@ -1316,6 +1334,7 @@ func registerPeerRESTHandlers(router *mux.Router) {
 	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodNetInfo).HandlerFunc(httpTraceHdrs(server.NetInfoHandler))
 	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodDispatchNetInfo).HandlerFunc(httpTraceHdrs(server.DispatchNetInfoHandler))
 	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodCycleBloom).HandlerFunc(httpTraceHdrs(server.CycleServerBloomFilterHandler))
+	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodGetAllBucketStats).HandlerFunc(httpTraceHdrs(server.GetAllBucketStatsHandler))
 	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodDeleteBucketMetadata).HandlerFunc(httpTraceHdrs(server.DeleteBucketMetadataHandler)).Queries(restQueries(peerRESTBucket)...)
 	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodLoadBucketMetadata).HandlerFunc(httpTraceHdrs(server.LoadBucketMetadataHandler)).Queries(restQueries(peerRESTBucket)...)
 	subrouter.Methods(http.MethodPost).Path(peerRESTVersionPrefix + peerRESTMethodGetBucketStats).HandlerFunc(httpTraceHdrs(server.GetBucketStatsHandler)).Queries(restQueries(peerRESTBucket)...)