diff --git a/go/topology/topology.go b/go/topology/topology.go
index 5b3d29e0b..24b3ab337 100644
--- a/go/topology/topology.go
+++ b/go/topology/topology.go
@@ -12,6 +12,8 @@ import (
 type Topology struct {
 	NodeImpl
 
+	IsLeader bool
+
 	collectionMap map[string]*Collection
 
 	pulse int64
diff --git a/go/topology/topology_event_handling.go b/go/topology/topology_event_handling.go
index 7f81d8184..5097e9874 100644
--- a/go/topology/topology_event_handling.go
+++ b/go/topology/topology_event_handling.go
@@ -10,15 +10,19 @@ import (
 func (t *Topology) StartRefreshWritableVolumes(garbageThreshold string) {
 	go func() {
 		for {
-			freshThreshHold := time.Now().Unix() - 3*t.pulse //3 times of sleep interval
-			t.CollectDeadNodeAndFullVolumes(freshThreshHold, t.volumeSizeLimit)
+			if t.IsLeader {
+				freshThreshHold := time.Now().Unix() - 3*t.pulse //3 times of sleep interval
+				t.CollectDeadNodeAndFullVolumes(freshThreshHold, t.volumeSizeLimit)
+			}
 			time.Sleep(time.Duration(float32(t.pulse*1e3)*(1+rand.Float32())) * time.Millisecond)
 		}
 	}()
 	go func(garbageThreshold string) {
 		c := time.Tick(15 * time.Minute)
-		for _ = range c {
-			t.Vacuum(garbageThreshold)
+		if t.IsLeader {
+			for _ = range c {
+				t.Vacuum(garbageThreshold)
+			}
 		}
 	}(garbageThreshold)
 	go func() {
diff --git a/go/weed/weed_server/master_server.go b/go/weed/weed_server/master_server.go
index d1f7914f1..738484ff0 100644
--- a/go/weed/weed_server/master_server.go
+++ b/go/weed/weed_server/master_server.go
@@ -5,6 +5,7 @@ import (
 	"code.google.com/p/weed-fs/go/replication"
 	"code.google.com/p/weed-fs/go/sequence"
 	"code.google.com/p/weed-fs/go/topology"
+	"github.com/goraft/raft"
 	"github.com/gorilla/mux"
 	"net/http"
 	"net/http/httputil"
@@ -72,6 +73,16 @@ func NewMasterServer(r *mux.Router, version string, port int, metaFolder string,
 
 func (ms *MasterServer) SetRaftServer(raftServer *RaftServer) {
 	ms.raftServer = raftServer
+	ms.raftServer.raftServer.AddEventListener(raft.LeaderChangeEventType, func(e raft.Event) {
+		ms.topo.IsLeader = ms.IsLeader()
+		glog.V(0).Infoln("[", ms.raftServer.Name(), "]", ms.raftServer.Leader(), "becomes leader.")
+	})
+	ms.topo.IsLeader = ms.IsLeader()
+	if ms.topo.IsLeader {
+		glog.V(0).Infoln("[", ms.raftServer.Name(), "]", "I am the leader!")
+	} else {
+		glog.V(0).Infoln("[", ms.raftServer.Name(), "]", ms.raftServer.Leader(), "is the leader.")
+	}
 }
 
 func (ms *MasterServer) IsLeader() bool {
diff --git a/go/weed/weed_server/raft_server.go b/go/weed/weed_server/raft_server.go
index a44936413..b481df68d 100644
--- a/go/weed/weed_server/raft_server.go
+++ b/go/weed/weed_server/raft_server.go
@@ -87,6 +87,10 @@ func NewRaftServer(r *mux.Router, version string, peers []string, httpAddr strin
 	return s
 }
 
+func (s *RaftServer) Name() string {
+	return s.raftServer.Name()
+}
+
 func (s *RaftServer) IsLeader() bool {
 	return s.Leader() == s.raftServer.Name()
 }