3 files changed, 57 insertions, 5 deletions
diff --git a/go/topology/cluster_commands.go b/go/topology/cluster_commands.go
new file mode 100644
index 000000000..dc0a40c8d
--- /dev/null
+++ b/go/topology/cluster_commands.go
@@ -0,0 +1,31 @@
+package topology
+
+import (
+	"code.google.com/p/weed-fs/go/glog"
+	"code.google.com/p/weed-fs/go/storage"
+	"github.com/goraft/raft"
+)
+
+type MaxVolumeIdCommand struct {
+	MaxVolumeId storage.VolumeId `json:"maxVolumeId"`
+}
+
+func NewMaxVolumeIdCommand(value storage.VolumeId) *MaxVolumeIdCommand {
+	return &MaxVolumeIdCommand{
+		MaxVolumeId: value,
+	}
+}
+
+func (c *MaxVolumeIdCommand) CommandName() string {
+	return "MaxVolumeId"
+}
+
+func (c *MaxVolumeIdCommand) Apply(server raft.Server) (interface{}, error) {
+	topo := server.Context().(*Topology)
+	before := topo.GetMaxVolumeId()
+	topo.UpAdjustMaxVolumeId(c.MaxVolumeId)
+
+	glog.V(0).Infoln("max volume id", before, "==>", topo.GetMaxVolumeId())
+
+	return nil, nil
+}
diff --git a/go/topology/topology.go b/go/topology/topology.go
index d72879035..055d273cd 100644
--- a/go/topology/topology.go
+++ b/go/topology/topology.go
@@ -5,6 +5,7 @@ import (
 	"code.google.com/p/weed-fs/go/sequence"
 	"code.google.com/p/weed-fs/go/storage"
 	"errors"
+	"github.com/goraft/raft"
 	"io/ioutil"
 	"math/rand"
 )
@@ -12,8 +13,6 @@ import (
 type Topology struct {
 	NodeImpl
 
-	IsLeader bool
-
 	collectionMap map[string]*Collection
 
 	pulse int64
@@ -27,6 +26,8 @@ type Topology struct {
 	chanFullVolumes        chan storage.VolumeInfo
 
 	configuration *Configuration
+
+	RaftServer raft.Server
 }
 
 func NewTopology(id string, confFile string, seq sequence.Sequencer, volumeSizeLimit uint64, pulse int) (*Topology, error) {
@@ -50,6 +51,24 @@ func NewTopology(id string, confFile string, seq sequence.Sequencer, volumeSizeL
 	return t, err
 }
 
+func (t *Topology) IsLeader() bool {
+	return t.RaftServer == nil || t.Leader() == t.RaftServer.Name()
+}
+
+func (t *Topology) Leader() string {
+	l := ""
+	if t.RaftServer != nil {
+		l = t.RaftServer.Leader()
+	}
+
+	if l == "" {
+		// We are a single node cluster, we are the leader
+		return t.RaftServer.Name()
+	}
+
+	return l
+}
+
 func (t *Topology) loadConfiguration(configurationFile string) error {
 	b, e := ioutil.ReadFile(configurationFile)
 	if e == nil {
@@ -79,7 +98,9 @@ func (t *Topology) Lookup(collection string, vid storage.VolumeId) []*DataNode {
 
 func (t *Topology) NextVolumeId() storage.VolumeId {
 	vid := t.GetMaxVolumeId()
-	return vid.Next()
+	next := vid.Next()
+	go t.RaftServer.Do(NewMaxVolumeIdCommand(next))
+	return next
 }
 
 func (t *Topology) PickForWrite(collectionName string, rp *storage.ReplicaPlacement, count int, dataCenter string) (string, int, *DataNode, error) {
diff --git a/go/topology/topology_event_handling.go b/go/topology/topology_event_handling.go
index 710e7b2ae..7398ff9bf 100644
--- a/go/topology/topology_event_handling.go
+++ b/go/topology/topology_event_handling.go
@@ -10,7 +10,7 @@ import (
 func (t *Topology) StartRefreshWritableVolumes(garbageThreshold string) {
 	go func() {
 		for {
-			if t.IsLeader {
+			if t.IsLeader() {
 				freshThreshHold := time.Now().Unix() - 3*t.pulse //3 times of sleep interval
 				t.CollectDeadNodeAndFullVolumes(freshThreshHold, t.volumeSizeLimit)
 			}
@@ -19,7 +19,7 @@ func (t *Topology) StartRefreshWritableVolumes(garbageThreshold string) {
 	}()
 	go func(garbageThreshold string) {
 		c := time.Tick(15 * time.Minute)
-		if t.IsLeader {
+		if t.IsLeader() {
 			for _ = range c {
 				t.Vacuum(garbageThreshold)
 			}