diff --git a/api/services/explorer/service.go b/api/services/explorer/service.go
index 831011864..d393a7f52 100644
--- a/api/services/explorer/service.go
+++ b/api/services/explorer/service.go
@@ -40,12 +40,14 @@ func New(selfPeer *p2p.Peer) *Service {
 
 // Start starts explorer service.
 func (s *Service) Start() {
+	utils.GetLogInstance().Info("Starting explorer service.")
 	s.Init(true)
 	s.server = s.Run()
 }
 
 // Stop shutdowns explorer service.
 func (s *Service) Stop() {
+	utils.GetLogInstance().Info("Shutting down explorer service.")
 	if err := s.server.Shutdown(context.Background()); err != nil {
 		utils.GetLogInstance().Error("Error when shutting down explorer server", "error", err)
 	} else {
diff --git a/cmd/harmony.go b/cmd/harmony.go
index df52b0d70..ff8919405 100644
--- a/cmd/harmony.go
+++ b/cmd/harmony.go
@@ -196,6 +196,11 @@ func main() {
 	// Current node.
 	currentNode := node.New(host, consensus, ldb)
 	currentNode.Consensus.OfflinePeers = currentNode.OfflinePeers
+	if role == "leader" {
+		currentNode.Role = node.ShardLeader
+	} else {
+		currentNode.Role = node.ShardValidator
+	}
 
 	// If there is a client configured in the node list.
 	if clientPeer != nil {
@@ -225,7 +230,7 @@ func main() {
 	go currentNode.SupportSyncing()
 	if consensus.IsLeader {
 		go currentNode.SupportClient()
-		go currentNode.SupportExplorer()
 	}
+	currentNode.AddAndRunServices()
 	currentNode.StartServer()
 }
diff --git a/node/node.go b/node/node.go
index 6abb31507..24b3147d7 100644
--- a/node/node.go
+++ b/node/node.go
@@ -52,6 +52,18 @@ const (
 	NodeLeader                         // Node is the leader of some shard.
 )
 
+// Role defines a role of a node.
+type Role byte
+
+// All constants for different node roles.
+const (
+	Unknown Role = iota
+	ShardLeader
+	ShardValidator
+	BeaconLeader
+	BeaconValidator
+)
+
 func (state State) String() string {
 	switch state {
 	case NodeInit:
@@ -143,6 +155,9 @@ type Node struct {
 	actionChannel chan *Action
 	serviceStore  *ServiceStore
 
+	// Node Role.
+	Role Role
+
 	// For test only
 	TestBankKeys      []*ecdsa.PrivateKey
 	ContractKeys      []*ecdsa.PrivateKey
@@ -308,6 +323,7 @@ func (node *Node) DoSyncing() {
 			node.stateMutex.Unlock()
 			continue
 		case consensusBlock := <-node.Consensus.ConsensusBlock:
+			// never reached from chao
 			if !node.IsOutOfSync(consensusBlock) {
 				if node.State == NodeNotInSync {
 					utils.GetLogInstance().Info("[SYNC] Node is now IN SYNC!")
@@ -457,16 +473,6 @@ func (node *Node) SupportClient() {
 	node.StartClientServer()
 }
 
-// SupportExplorer initializes and starts the client service
-func (node *Node) SupportExplorer() {
-	es := explorer.Service{
-		IP:   node.SelfPeer.IP,
-		Port: node.SelfPeer.Port,
-	}
-	es.Init(true)
-	es.Run()
-}
-
 // InitClientServer initializes client server.
 func (node *Node) InitClientServer() {
 	node.clientServer = clientService.NewServer(node.blockchain.State, node.CallFaucetContract)
@@ -483,6 +489,7 @@ func (node *Node) StartClientServer() {
 func (node *Node) SupportSyncing() {
 	node.InitSyncingServer()
 	node.StartSyncingServer()
+
 	go node.DoSyncing()
 	go node.SendNewBlockToUnsync()
 }
@@ -494,8 +501,7 @@ func (node *Node) InitSyncingServer() {
 
 // StartSyncingServer starts syncing server.
 func (node *Node) StartSyncingServer() {
-	port := GetSyncingPort(node.SelfPeer.Port)
-	utils.GetLogInstance().Info("support_sycning: StartSyncingServer on port:", "port", port)
+	utils.GetLogInstance().Info("support_sycning: StartSyncingServer")
 	node.downloaderServer.Start(node.SelfPeer.IP, GetSyncingPort(node.SelfPeer.Port))
 }
 
@@ -625,3 +631,17 @@ func (node *Node) RemovePeersHandler() {
 		}
 	}
 }
+
+// AddAndRunServices manually adds certain services and start them.
+func (node *Node) AddAndRunServices() {
+	node.SetupServiceManager()
+
+	switch node.Role {
+	case ShardLeader:
+		// Add and run explorer.
+		node.RegisterService(SupportExplorer, explorer.New(&node.SelfPeer))
+		node.actionChannel <- &Action{action: Start, serviceType: SupportExplorer}
+	case Unknown:
+		utils.GetLogInstance().Info("Running node services")
+	}
+}
diff --git a/node/service.go b/node/service.go
index c7d8c2e32..9c487a8bd 100644
--- a/node/service.go
+++ b/node/service.go
@@ -48,7 +48,7 @@ func (t ServiceType) String() string {
 // Constants for timing.
 const (
 	// WaitForStatusUpdate is the delay time to update new status. Currently set 1 second for development. Should be 30 minutes for production.
-	WaitForStatusUpdate = time.Second * 1
+	WaitForStatusUpdate = time.Minute * 1
 )
 
 // Action is type of service action.
@@ -88,7 +88,7 @@ func (node *Node) RegisterService(t ServiceType, service ServiceInterface) {
 	node.serviceStore.Register(t, service)
 }
 
-// RegisterServices registers all service for a node with its role.
+// InitServiceMap initializes service map.
 func (node *Node) InitServiceMap() {
 	node.serviceStore = &ServiceStore{services: make(map[ServiceType]ServiceInterface)}
 }