leveldb2: support subscribing from peers

weed/filer2/filer.go

@@ -68,7 +68,7 @@ func (f *Filer) AggregateFromPeers(self string, filers []string) {
 		filers = append(filers, self)
 	}
 	f.MetaAggregator = NewMetaAggregator(filers, f.GrpcDialOption)
-	f.MetaAggregator.StartLoopSubscribe(time.Now().UnixNano())
+	f.MetaAggregator.StartLoopSubscribe(f, self, time.Now().UnixNano())
 
 }
 

weed/filer2/filerstore.go

@@ -29,6 +29,11 @@ type FilerStore interface {
 	Shutdown()
 }
 
+type FilerLocalStore interface {
+	UpdateOffset(filer string, lastTsNs int64) error
+	ReadOffset(filer string) (lastTsNs int64, err error)
+}
+
 type FilerStoreWrapper struct {
 	actualStore FilerStore
 }

weed/filer2/leveldb2/leveldb2_local_store.go

@@ -0,0 +1,47 @@
+package leveldb
+
+import (
+	"fmt"
+
+	"github.com/chrislusf/seaweedfs/weed/filer2"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+func init() {
+	filer2.Stores = append(filer2.Stores, &LevelDB2Store{})
+}
+
+var (
+	_ = filer2.FilerLocalStore(&LevelDB2Store{})
+)
+
+func (store *LevelDB2Store) UpdateOffset(filer string, lastTsNs int64) error {
+
+	value := make([]byte, 8)
+	util.Uint64toBytes(value, uint64(lastTsNs))
+
+	err := store.dbs[0].Put([]byte("meta"+filer), value, nil)
+
+	if err != nil {
+		return fmt.Errorf("UpdateOffset %s : %v", filer, err)
+	}
+
+	println("UpdateOffset", filer, "lastTsNs", lastTsNs)
+
+	return nil
+}
+
+func (store *LevelDB2Store) ReadOffset(filer string) (lastTsNs int64, err error) {
+
+	value, err := store.dbs[0].Get([]byte("meta"+filer), nil)
+
+	if err != nil {
+		return 0, fmt.Errorf("ReadOffset %s : %v", filer, err)
+	}
+
+	lastTsNs = int64(util.BytesToUint64(value))
+
+	println("ReadOffset", filer, "lastTsNs", lastTsNs)
+
+	return
+}

weed/filer2/meta_aggregator.go

@@ -37,13 +37,42 @@ func NewMetaAggregator(filers []string, grpcDialOption grpc.DialOption) *MetaAgg
 	return t
 }
 
-func (ma *MetaAggregator) StartLoopSubscribe(lastTsNs int64) {
+func (ma *MetaAggregator) StartLoopSubscribe(f *Filer, self string, lastTsNs int64) {
 	for _, filer := range ma.filers {
-		go ma.subscribeToOneFiler(filer, lastTsNs)
+		go ma.subscribeToOneFiler(f, self, filer, lastTsNs)
 	}
 }
 
-func (ma *MetaAggregator) subscribeToOneFiler(filer string, lastTsNs int64) {
+func (ma *MetaAggregator) subscribeToOneFiler(f *Filer, filer string, self string, lastTsNs int64) {
+
+	var maybeReplicateMetadataChange func(*filer_pb.SubscribeMetadataResponse)
+	lastPersistTime := time.Now()
+	changesSinceLastPersist := 0
+
+	MaxChangeLimit := 100
+
+	if localStore, ok := f.store.actualStore.(FilerLocalStore); ok {
+		if prevTsNs, err := localStore.ReadOffset(filer); err == nil {
+			lastTsNs = prevTsNs
+		}
+		if self != filer {
+			maybeReplicateMetadataChange = func(event *filer_pb.SubscribeMetadataResponse) {
+				if err := Replay(f.store.actualStore, event); err != nil {
+					glog.Errorf("failed to reply metadata change from %v: %v", filer, err)
+					return
+				}
+				changesSinceLastPersist++
+				if changesSinceLastPersist >= MaxChangeLimit || lastPersistTime.Add(time.Minute).Before(time.Now()) {
+					if err := localStore.UpdateOffset(filer, event.TsNs); err == nil {
+						lastPersistTime = time.Now()
+						changesSinceLastPersist = 0
+					} else {
+						glog.V(0).Infof("failed to update offset for %v: %v", filer, err)
+					}
+				}
+			}
+		}
+	}
 
 	processEventFn := func(event *filer_pb.SubscribeMetadataResponse) error {
 		data, err := proto.Marshal(event)
@@ -54,6 +83,9 @@ func (ma *MetaAggregator) subscribeToOneFiler(filer string, lastTsNs int64) {
 		dir := event.Directory
 		// println("received meta change", dir, "size", len(data))
 		ma.MetaLogBuffer.AddToBuffer([]byte(dir), data)
+		if maybeReplicateMetadataChange != nil {
+			maybeReplicateMetadataChange(event)
+		}
 		return nil
 	}
 

weed/filer2/meta_replay.go

@@ -0,0 +1,37 @@
+package filer2
+
+import (
+	"context"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+func Replay(filerStore FilerStore, resp *filer_pb.SubscribeMetadataResponse) error {
+	message := resp.EventNotification
+	var oldPath util.FullPath
+	var newEntry *Entry
+	if message.OldEntry != nil {
+		oldPath = util.NewFullPath(resp.Directory, message.OldEntry.Name)
+		glog.V(4).Infof("deleting %v", oldPath)
+		if err := filerStore.DeleteEntry(context.Background(), oldPath); err != nil {
+			return err
+		}
+	}
+
+	if message.NewEntry != nil {
+		dir := resp.Directory
+		if message.NewParentPath != "" {
+			dir = message.NewParentPath
+		}
+		key := util.NewFullPath(dir, message.NewEntry.Name)
+		glog.V(4).Infof("creating %v", key)
+		newEntry = FromPbEntry(dir, message.NewEntry)
+		if err := filerStore.InsertEntry(context.Background(), newEntry); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}