diff --git a/core/constants/node.go b/core/constants/node.go
index 464c517c..1736a413 100644
--- a/core/constants/node.go
+++ b/core/constants/node.go
@@ -1,8 +1,6 @@
 package constants
 
 const (
-	NodeStatusUnregistered = "u"
-	NodeStatusRegistered   = "r"
-	NodeStatusOnline       = "on"
-	NodeStatusOffline      = "off"
+	NodeStatusOnline  = "on"
+	NodeStatusOffline = "off"
 )
diff --git a/core/constants/task.go b/core/constants/task.go
index aaa71c11..22a10662 100644
--- a/core/constants/task.go
+++ b/core/constants/task.go
@@ -2,6 +2,7 @@ package constants
 
 const (
 	TaskStatusPending   = "pending"
+	TaskStatusAssigned  = "assigned"
 	TaskStatusRunning   = "running"
 	TaskStatusFinished  = "finished"
 	TaskStatusError     = "error"
diff --git a/core/controllers/spider_v2.go b/core/controllers/spider_v2.go
index 9a8e6ca7..2cc2ae26 100644
--- a/core/controllers/spider_v2.go
+++ b/core/controllers/spider_v2.go
@@ -653,7 +653,7 @@ func PostSpiderRun(c *gin.Context) {
 		opts.UserId = u.GetId()
 	}
 
-	adminSvc, err := admin.GetSpiderAdminServiceV2()
+	adminSvc, err := admin.GetSpiderAdminService()
 	if err != nil {
 		HandleErrorInternalServerError(c, err)
 		return
diff --git a/core/controllers/task_v2.go b/core/controllers/task_v2.go
index 829ad385..2fb15252 100644
--- a/core/controllers/task_v2.go
+++ b/core/controllers/task_v2.go
@@ -305,7 +305,7 @@ func PostTaskRun(c *gin.Context) {
 	}
 
 	// run
-	adminSvc, err := admin.GetSpiderAdminServiceV2()
+	adminSvc, err := admin.GetSpiderAdminService()
 	if err != nil {
 		HandleErrorInternalServerError(c, err)
 		return
@@ -350,7 +350,7 @@ func PostTaskRestart(c *gin.Context) {
 	}
 
 	// run
-	adminSvc, err := admin.GetSpiderAdminServiceV2()
+	adminSvc, err := admin.GetSpiderAdminService()
 	if err != nil {
 		HandleErrorInternalServerError(c, err)
 		return
@@ -399,7 +399,7 @@ func PostTaskCancel(c *gin.Context) {
 	u := GetUserFromContext(c)
 
 	// cancel
-	schedulerSvc, err := scheduler.GetTaskSchedulerServiceV2()
+	schedulerSvc, err := scheduler.GetTaskSchedulerService()
 	if err != nil {
 		HandleErrorInternalServerError(c, err)
 		return
diff --git a/core/grpc/client/client.go b/core/grpc/client/client.go
index 9d3c9165..94d6d939 100644
--- a/core/grpc/client/client.go
+++ b/core/grpc/client/client.go
@@ -141,6 +141,8 @@ func (c *GrpcClient) connect() (err error) {
 			return err
 		}
 
+		// connect
+		c.conn.Connect()
 		log.Infof("[GrpcClient] grpc client connected to %s", address)
 
 		return nil
diff --git a/core/grpc/server/node_service_server.go b/core/grpc/server/node_service_server.go
index 3c504266..661aef6f 100644
--- a/core/grpc/server/node_service_server.go
+++ b/core/grpc/server/node_service_server.go
@@ -16,7 +16,6 @@ import (
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"go.mongodb.org/mongo-driver/mongo"
-	"io"
 	"sync"
 	"time"
 )
@@ -30,8 +29,7 @@ type NodeServiceServer struct {
 	cfgSvc interfaces.NodeConfigService
 
 	// internals
-	server *GrpcServer
-	subs   map[primitive.ObjectID]grpc.NodeService_SubscribeServer
+	subs map[primitive.ObjectID]grpc.NodeService_SubscribeServer
 }
 
 // Register from handler/worker to master
@@ -46,7 +44,7 @@ func (svr NodeServiceServer) Register(_ context.Context, req *grpc.NodeServiceRe
 	node, err = service.NewModelServiceV2[models.NodeV2]().GetOne(bson.M{"key": req.NodeKey}, nil)
 	if err == nil {
 		// register existing
-		node.Status = constants.NodeStatusRegistered
+		node.Status = constants.NodeStatusOnline
 		node.Active = true
 		node.ActiveAt = time.Now()
 		err = service.NewModelServiceV2[models.NodeV2]().ReplaceById(node.Id, *node)
@@ -59,7 +57,7 @@ func (svr NodeServiceServer) Register(_ context.Context, req *grpc.NodeServiceRe
 		node = &models.NodeV2{
 			Key:        req.NodeKey,
 			Name:       req.NodeName,
-			Status:     constants.NodeStatusRegistered,
+			Status:     constants.NodeStatusOnline,
 			Active:     true,
 			ActiveAt:   time.Now(),
 			Enabled:    true,
@@ -94,11 +92,6 @@ func (svr NodeServiceServer) SendHeartbeat(_ context.Context, req *grpc.NodeServ
 	}
 	oldStatus := node.Status
 
-	// validate status
-	if node.Status == constants.NodeStatusUnregistered {
-		return HandleError(errors.ErrorNodeUnregistered)
-	}
-
 	// update status
 	node.Status = constants.NodeStatusOnline
 	node.Active = true
@@ -136,26 +129,14 @@ func (svr NodeServiceServer) Subscribe(request *grpc.NodeServiceSubscribeRequest
 
 	// TODO: send notification
 
-	// create a new goroutine to receive messages from the stream to listen for EOF (end of stream)
-	go func() {
-		for {
-			select {
-			case <-stream.Context().Done():
-				nodeServiceMutex.Lock()
-				delete(svr.subs, node.Id)
-				nodeServiceMutex.Unlock()
-				return
-			default:
-				err := stream.RecvMsg(nil)
-				if err == io.EOF {
-					nodeServiceMutex.Lock()
-					delete(svr.subs, node.Id)
-					nodeServiceMutex.Unlock()
-					return
-				}
-			}
-		}
-	}()
+	// wait for stream to close
+	<-stream.Context().Done()
+
+	// unsubscribe
+	nodeServiceMutex.Lock()
+	delete(svr.subs, node.Id)
+	nodeServiceMutex.Unlock()
+	log.Infof("[NodeServiceServer] master unsubscribed from node[%s]", request.NodeKey)
 
 	return nil
 }
@@ -167,16 +148,18 @@ func (svr NodeServiceServer) GetSubscribeStream(nodeId primitive.ObjectID) (stre
 	return stream, ok
 }
 
-var nodeSvrV2 *NodeServiceServer
-var nodeSvrV2Once = new(sync.Once)
+var nodeSvr *NodeServiceServer
+var nodeSvrOnce = new(sync.Once)
 
 func NewNodeServiceServer() (res *NodeServiceServer, err error) {
-	if nodeSvrV2 != nil {
-		return nodeSvrV2, nil
+	if nodeSvr != nil {
+		return nodeSvr, nil
 	}
-	nodeSvrV2Once.Do(func() {
-		nodeSvrV2 = &NodeServiceServer{}
-		nodeSvrV2.cfgSvc = nodeconfig.GetNodeConfigService()
+	nodeSvrOnce.Do(func() {
+		nodeSvr = &NodeServiceServer{
+			subs: make(map[primitive.ObjectID]grpc.NodeService_SubscribeServer),
+		}
+		nodeSvr.cfgSvc = nodeconfig.GetNodeConfigService()
 		if err != nil {
 			log.Errorf("[NodeServiceServer] error: %s", err.Error())
 		}
@@ -184,5 +167,5 @@ func NewNodeServiceServer() (res *NodeServiceServer, err error) {
 	if err != nil {
 		return nil, err
 	}
-	return nodeSvrV2, nil
+	return nodeSvr, nil
 }
diff --git a/core/grpc/server/task_service_server.go b/core/grpc/server/task_service_server.go
index f2230786..7800c6ad 100644
--- a/core/grpc/server/task_service_server.go
+++ b/core/grpc/server/task_service_server.go
@@ -54,26 +54,14 @@ func (svr TaskServiceServer) Subscribe(req *grpc.TaskServiceSubscribeRequest, st
 	svr.subs[taskId] = stream
 	taskServiceMutex.Unlock()
 
-	// create a new goroutine to receive messages from the stream to listen for EOF (end of stream)
-	go func() {
-		for {
-			select {
-			case <-stream.Context().Done():
-				taskServiceMutex.Lock()
-				delete(svr.subs, taskId)
-				taskServiceMutex.Unlock()
-				return
-			default:
-				err := stream.RecvMsg(nil)
-				if err == io.EOF {
-					taskServiceMutex.Lock()
-					delete(svr.subs, taskId)
-					taskServiceMutex.Unlock()
-					return
-				}
-			}
-		}
-	}()
+	// wait for stream to close
+	<-stream.Context().Done()
+
+	// remove stream
+	taskServiceMutex.Lock()
+	delete(svr.subs, taskId)
+	taskServiceMutex.Unlock()
+	log.Infof("[TaskServiceServer] task stream closed: %s", taskId.Hex())
 
 	return nil
 }
@@ -129,33 +117,47 @@ func (svr TaskServiceServer) FetchTask(ctx context.Context, request *grpc.TaskSe
 	var tid primitive.ObjectID
 	opts := &mongo.FindOptions{
 		Sort: bson.D{
-			{"p", 1},
+			{"priority", 1},
 			{"_id", 1},
 		},
 		Limit: 1,
 	}
 	if err := mongo.RunTransactionWithContext(ctx, func(sc mongo2.SessionContext) (err error) {
-		// get task queue item assigned to this node
-		tid, err = svr.getTaskQueueItemIdAndDequeue(bson.M{"nid": n.Id}, opts, n.Id)
-		if err != nil {
+		// fetch task for the given node
+		t, err := service.NewModelServiceV2[models2.TaskV2]().GetOne(bson.M{
+			"node_id": n.Id,
+			"status":  constants.TaskStatusPending,
+		}, opts)
+		if err == nil {
+			tid = t.Id
+			t.Status = constants.TaskStatusAssigned
+			return svr.saveTask(t)
+		} else if !errors.Is(err, mongo2.ErrNoDocuments) {
+			log.Errorf("error fetching task for node[%s]: %v", nodeKey, err)
 			return err
 		}
-		if !tid.IsZero() {
-			return nil
-		}
 
-		// get task queue item assigned to any node (random mode)
-		tid, err = svr.getTaskQueueItemIdAndDequeue(bson.M{"nid": nil}, opts, n.Id)
-		if !tid.IsZero() {
-			return nil
-		}
-		if err != nil {
+		// fetch task for any node
+		t, err = service.NewModelServiceV2[models2.TaskV2]().GetOne(bson.M{
+			"node_id": primitive.NilObjectID,
+			"status":  constants.TaskStatusPending,
+		}, opts)
+		if err == nil {
+			tid = t.Id
+			t.NodeId = n.Id
+			t.Status = constants.TaskStatusAssigned
+			return svr.saveTask(t)
+		} else if !errors.Is(err, mongo2.ErrNoDocuments) {
+			log.Errorf("error fetching task for any node: %v", err)
 			return err
 		}
+
+		// no task found
 		return nil
 	}); err != nil {
 		return nil, err
 	}
+
 	return &grpc.TaskServiceFetchTaskResponse{TaskId: tid.Hex()}, nil
 }
 
@@ -284,32 +286,16 @@ func (svr TaskServiceServer) handleInsertLogs(taskId primitive.ObjectID, msg *gr
 	return svr.statsSvc.InsertLogs(taskId, logs...)
 }
 
-func (svr TaskServiceServer) getTaskQueueItemIdAndDequeue(query bson.M, opts *mongo.FindOptions, nid primitive.ObjectID) (tid primitive.ObjectID, err error) {
-	tq, err := service.NewModelServiceV2[models2.TaskQueueItemV2]().GetOne(query, opts)
-	if err != nil {
-		if errors.Is(err, mongo2.ErrNoDocuments) {
-			return tid, nil
-		}
-		return tid, trace.TraceError(err)
-	}
-	t, err := service.NewModelServiceV2[models2.TaskV2]().GetById(tq.Id)
-	if err == nil {
-		t.NodeId = nid
-		err = service.NewModelServiceV2[models2.TaskV2]().ReplaceById(t.Id, *t)
-		if err != nil {
-			return tid, trace.TraceError(err)
-		}
-	}
-	err = service.NewModelServiceV2[models2.TaskQueueItemV2]().DeleteById(tq.Id)
-	if err != nil {
-		return tid, trace.TraceError(err)
-	}
-	return tq.Id, nil
+func (svr TaskServiceServer) saveTask(t *models2.TaskV2) (err error) {
+	t.SetUpdated(t.CreatedBy)
+	return service.NewModelServiceV2[models2.TaskV2]().ReplaceById(t.Id, *t)
 }
 
 func NewTaskServiceServer() (res *TaskServiceServer, err error) {
 	// task server
-	svr := &TaskServiceServer{}
+	svr := &TaskServiceServer{
+		subs: make(map[primitive.ObjectID]grpc.TaskService_SubscribeServer),
+	}
 
 	svr.cfgSvc = nodeconfig.GetNodeConfigService()
 
diff --git a/core/models/common/init.go b/core/models/common/init_index.go
similarity index 98%
rename from core/models/common/init.go
rename to core/models/common/init_index.go
index 69fa4348..c3872a42 100644
--- a/core/models/common/init.go
+++ b/core/models/common/init_index.go
@@ -45,6 +45,7 @@ func InitIndexes() {
 		{Keys: bson.M{"parent_id": 1}},
 		{Keys: bson.M{"has_sub": 1}},
 		{Keys: bson.M{"created_ts": -1}, Options: (&options.IndexOptions{}).SetExpireAfterSeconds(60 * 60 * 24 * 30)},
+		{Keys: bson.M{"node_id": 1, "status": 1}},
 	})
 
 	// task stats
diff --git a/core/models/models/v2/base_v2.go b/core/models/models/v2/base_v2.go
index 92cfed63..851f261b 100644
--- a/core/models/models/v2/base_v2.go
+++ b/core/models/models/v2/base_v2.go
@@ -91,7 +91,6 @@ func GetModelInstances() []any {
 		*new(SettingV2),
 		*new(SpiderV2),
 		*new(SpiderStatV2),
-		*new(TaskQueueItemV2),
 		*new(TaskStatV2),
 		*new(TaskV2),
 		*new(TokenV2),
diff --git a/core/models/models/v2/task_queue_item_v2.go b/core/models/models/v2/task_queue_item_v2.go
deleted file mode 100644
index f222aef3..00000000
--- a/core/models/models/v2/task_queue_item_v2.go
+++ /dev/null
@@ -1,12 +0,0 @@
-package models
-
-import (
-	"go.mongodb.org/mongo-driver/bson/primitive"
-)
-
-type TaskQueueItemV2 struct {
-	any                          `collection:"task_queue"`
-	BaseModelV2[TaskQueueItemV2] `bson:",inline"`
-	Priority                     int                `json:"p" bson:"p"`
-	NodeId                       primitive.ObjectID `json:"nid,omitempty" bson:"nid,omitempty"`
-}
diff --git a/core/models/models/v2/task_v2.go b/core/models/models/v2/task_v2.go
index 849cdf40..ad7fb05b 100644
--- a/core/models/models/v2/task_v2.go
+++ b/core/models/models/v2/task_v2.go
@@ -18,11 +18,8 @@ type TaskV2 struct {
 	Type                string               `json:"type" bson:"type"`
 	Mode                string               `json:"mode" bson:"mode"`
 	NodeIds             []primitive.ObjectID `json:"node_ids" bson:"node_ids"`
-	ParentId            primitive.ObjectID   `json:"parent_id" bson:"parent_id"`
 	Priority            int                  `json:"priority" bson:"priority"`
 	Stat                *TaskStatV2          `json:"stat,omitempty" bson:"-"`
-	HasSub              bool                 `json:"has_sub" json:"has_sub"`
-	SubTasks            []TaskV2             `json:"sub_tasks,omitempty" bson:"-"`
 	Spider              *SpiderV2            `json:"spider,omitempty" bson:"-"`
 	Schedule            *ScheduleV2          `json:"schedule,omitempty" bson:"-"`
 	Node                *NodeV2              `json:"node,omitempty" bson:"-"`
diff --git a/core/node/service/master_service.go b/core/node/service/master_service.go
index fa6736a5..02cf0d52 100644
--- a/core/node/service/master_service.go
+++ b/core/node/service/master_service.go
@@ -31,7 +31,7 @@ type MasterService struct {
 	// dependencies
 	cfgSvc       interfaces.NodeConfigService
 	server       *server.GrpcServer
-	schedulerSvc *scheduler.ServiceV2
+	schedulerSvc *scheduler.Service
 	handlerSvc   *handler.Service
 	scheduleSvc  *schedule.ServiceV2
 	systemSvc    *system.ServiceV2
@@ -339,7 +339,7 @@ func newMasterServiceV2() (res *MasterService, err error) {
 	}
 
 	// scheduler service
-	svc.schedulerSvc, err = scheduler.GetTaskSchedulerServiceV2()
+	svc.schedulerSvc, err = scheduler.GetTaskSchedulerService()
 	if err != nil {
 		return nil, err
 	}
diff --git a/core/node/service/worker_service.go b/core/node/service/worker_service.go
index 3d26c892..712c6456 100644
--- a/core/node/service/worker_service.go
+++ b/core/node/service/worker_service.go
@@ -2,8 +2,11 @@ package service
 
 import (
 	"context"
-	"errors"
+	"sync"
+	"time"
+
 	"github.com/apex/log"
+	"github.com/cenkalti/backoff/v4"
 	"github.com/crawlab-team/crawlab/core/config"
 	"github.com/crawlab-team/crawlab/core/grpc/client"
 	"github.com/crawlab-team/crawlab/core/interfaces"
@@ -15,9 +18,6 @@ import (
 	"github.com/crawlab-team/crawlab/grpc"
 	"github.com/crawlab-team/crawlab/trace"
 	"go.mongodb.org/mongo-driver/bson"
-	"io"
-	"sync"
-	"time"
 )
 
 type WorkerService struct {
@@ -49,13 +49,13 @@ func (svc *WorkerService) Start() {
 	}
 
 	// register to master
-	svc.Register()
+	svc.register()
 
 	// subscribe
-	svc.Subscribe()
+	go svc.subscribe()
 
 	// start sending heartbeat to master
-	go svc.ReportStatus()
+	go svc.reportStatus()
 
 	// start handler
 	go svc.handlerSvc.Start()
@@ -78,7 +78,7 @@ func (svc *WorkerService) Stop() {
 	log.Infof("worker[%s] service has stopped", svc.cfgSvc.GetNodeKey())
 }
 
-func (svc *WorkerService) Register() {
+func (svc *WorkerService) register() {
 	ctx, cancel := svc.client.Context()
 	defer cancel()
 	_, err := svc.client.NodeClient.Register(ctx, &grpc.NodeServiceRegisterRequest{
@@ -87,17 +87,19 @@ func (svc *WorkerService) Register() {
 		MaxRunners: int32(svc.cfgSvc.GetMaxRunners()),
 	})
 	if err != nil {
+		log.Fatalf("failed to register worker[%s] to master: %v", svc.cfgSvc.GetNodeKey(), err)
 		panic(err)
 	}
 	svc.n, err = client2.NewModelServiceV2[models.NodeV2]().GetOne(bson.M{"key": svc.GetConfigService().GetNodeKey()}, nil)
 	if err != nil {
+		log.Fatalf("failed to get node: %v", err)
 		panic(err)
 	}
 	log.Infof("worker[%s] registered to master. id: %s", svc.GetConfigService().GetNodeKey(), svc.n.Id.Hex())
 	return
 }
 
-func (svc *WorkerService) ReportStatus() {
+func (svc *WorkerService) reportStatus() {
 	ticker := time.NewTicker(svc.heartbeatInterval)
 	for {
 		// return if client is closed
@@ -106,8 +108,8 @@ func (svc *WorkerService) ReportStatus() {
 			return
 		}
 
-		// report status
-		svc.reportStatus()
+		// send heartbeat
+		svc.sendHeartbeat()
 
 		// sleep
 		<-ticker.C
@@ -126,49 +128,65 @@ func (svc *WorkerService) SetConfigPath(path string) {
 	svc.cfgPath = path
 }
 
-func (svc *WorkerService) GetAddress() (address interfaces.Address) {
-	return svc.address
-}
+func (svc *WorkerService) subscribe() {
+	// Configure exponential backoff
+	b := backoff.NewExponentialBackOff()
+	b.InitialInterval = 1 * time.Second
+	b.MaxInterval = 1 * time.Minute
+	b.MaxElapsedTime = 10 * time.Minute
+	b.Multiplier = 2.0
 
-func (svc *WorkerService) SetAddress(address interfaces.Address) {
-	svc.address = address
-}
-
-func (svc *WorkerService) SetHeartbeatInterval(duration time.Duration) {
-	svc.heartbeatInterval = duration
-}
-
-func (svc *WorkerService) Subscribe() {
-	stream, err := svc.client.NodeClient.Subscribe(context.Background(), &grpc.NodeServiceSubscribeRequest{
-		NodeKey: svc.cfgSvc.GetNodeKey(),
-	})
-	if err != nil {
-		log.Errorf("failed to subscribe to master: %v", err)
-		return
-	}
 	for {
 		if svc.stopped {
 			return
 		}
-		select {
-		default:
-			msg, err := stream.Recv()
+
+		// Use backoff for connection attempts
+		operation := func() error {
+			stream, err := svc.client.NodeClient.Subscribe(context.Background(), &grpc.NodeServiceSubscribeRequest{
+				NodeKey: svc.cfgSvc.GetNodeKey(),
+			})
 			if err != nil {
-				if errors.Is(err, io.EOF) {
-					return
-				}
-				log.Errorf("failed to receive message from master: %v", err)
-				continue
+				log.Errorf("failed to subscribe to master: %v", err)
+				return err
 			}
-			switch msg.Code {
-			case grpc.NodeServiceSubscribeCode_PING:
-				// do nothing
+
+			// Handle messages
+			for {
+				if svc.stopped {
+					return nil
+				}
+
+				msg, err := stream.Recv()
+				if err != nil {
+					if svc.client.IsClosed() {
+						log.Errorf("connection to master is closed: %v", err)
+						return err
+					}
+					log.Errorf("failed to receive message from master: %v", err)
+					return err
+				}
+
+				switch msg.Code {
+				case grpc.NodeServiceSubscribeCode_PING:
+					// do nothing
+				}
 			}
 		}
+
+		// Execute with backoff
+		err := backoff.Retry(operation, b)
+		if err != nil {
+			log.Errorf("subscription failed after max retries: %v", err)
+			return
+		}
+
+		// Wait before attempting to reconnect
+		time.Sleep(time.Second)
 	}
 }
 
-func (svc *WorkerService) reportStatus() {
+func (svc *WorkerService) sendHeartbeat() {
 	ctx, cancel := context.WithTimeout(context.Background(), svc.heartbeatInterval)
 	defer cancel()
 	_, err := svc.client.NodeClient.SendHeartbeat(ctx, &grpc.NodeServiceSendHeartbeatRequest{
diff --git a/core/schedule/service_v2.go b/core/schedule/service_v2.go
index a1a244ac..0b102574 100644
--- a/core/schedule/service_v2.go
+++ b/core/schedule/service_v2.go
@@ -20,7 +20,7 @@ type ServiceV2 struct {
 	// dependencies
 	interfaces.WithConfigPath
 	modelSvc *service.ModelServiceV2[models2.ScheduleV2]
-	adminSvc *admin.ServiceV2
+	adminSvc *admin.Service
 
 	// settings variables
 	loc            *time.Location
@@ -246,7 +246,7 @@ func NewScheduleServiceV2() (svc2 *ServiceV2, err error) {
 		skip:           false,
 		updateInterval: 1 * time.Minute,
 	}
-	svc.adminSvc, err = admin.GetSpiderAdminServiceV2()
+	svc.adminSvc, err = admin.GetSpiderAdminService()
 	if err != nil {
 		return nil, err
 	}
diff --git a/core/spider/admin/service_v2.go b/core/spider/admin/service.go
similarity index 55%
rename from core/spider/admin/service_v2.go
rename to core/spider/admin/service.go
index ee4046dc..b09a9bd5 100644
--- a/core/spider/admin/service_v2.go
+++ b/core/spider/admin/service.go
@@ -11,24 +11,22 @@ import (
 	"github.com/crawlab-team/crawlab/core/node/config"
 	"github.com/crawlab-team/crawlab/core/task/scheduler"
 	"github.com/crawlab-team/crawlab/trace"
-	"github.com/robfig/cron/v3"
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/bson/primitive"
 	"sync"
 )
 
-type ServiceV2 struct {
+type Service struct {
 	// dependencies
 	nodeCfgSvc   interfaces.NodeConfigService
-	schedulerSvc *scheduler.ServiceV2
-	cron         *cron.Cron
+	schedulerSvc *scheduler.Service
 	syncLock     bool
 
 	// settings
 	cfgPath string
 }
 
-func (svc *ServiceV2) Schedule(id primitive.ObjectID, opts *interfaces.SpiderRunOptions) (taskIds []primitive.ObjectID, err error) {
+func (svc *Service) Schedule(id primitive.ObjectID, opts *interfaces.SpiderRunOptions) (taskIds []primitive.ObjectID, err error) {
 	// spider
 	s, err := service.NewModelServiceV2[models2.SpiderV2]().GetById(id)
 	if err != nil {
@@ -39,53 +37,58 @@ func (svc *ServiceV2) Schedule(id primitive.ObjectID, opts *interfaces.SpiderRun
 	return svc.scheduleTasks(s, opts)
 }
 
-func (svc *ServiceV2) scheduleTasks(s *models2.SpiderV2, opts *interfaces.SpiderRunOptions) (taskIds []primitive.ObjectID, err error) {
-	// main task
-	t := &models2.TaskV2{
-		SpiderId:   s.Id,
-		Mode:       opts.Mode,
-		NodeIds:    opts.NodeIds,
-		Cmd:        opts.Cmd,
-		Param:      opts.Param,
-		ScheduleId: opts.ScheduleId,
-		Priority:   opts.Priority,
-	}
-	t.SetId(primitive.NewObjectID())
-
-	// normalize
-	if t.Mode == "" {
-		t.Mode = s.Mode
-	}
-	if t.NodeIds == nil {
-		t.NodeIds = s.NodeIds
-	}
-	if t.Cmd == "" {
-		t.Cmd = s.Cmd
-	}
-	if t.Param == "" {
-		t.Param = s.Param
-	}
-	if t.Priority == 0 {
-		t.Priority = s.Priority
-	}
-
+func (svc *Service) scheduleTasks(s *models2.SpiderV2, opts *interfaces.SpiderRunOptions) (taskIds []primitive.ObjectID, err error) {
+	// get node ids
 	nodeIds, err := svc.getNodeIds(opts)
 	if err != nil {
 		return nil, err
 	}
-	if len(nodeIds) > 0 {
-		t.NodeId = nodeIds[0]
+
+	// iterate node ids
+	for _, nodeId := range nodeIds {
+		// task
+		t := &models2.TaskV2{
+			SpiderId:   s.Id,
+			NodeId:     nodeId,
+			NodeIds:    opts.NodeIds,
+			Mode:       opts.Mode,
+			Cmd:        opts.Cmd,
+			Param:      opts.Param,
+			ScheduleId: opts.ScheduleId,
+			Priority:   opts.Priority,
+		}
+
+		// normalize
+		if t.Mode == "" {
+			t.Mode = s.Mode
+		}
+		if t.NodeIds == nil {
+			t.NodeIds = s.NodeIds
+		}
+		if t.Cmd == "" {
+			t.Cmd = s.Cmd
+		}
+		if t.Param == "" {
+			t.Param = s.Param
+		}
+		if t.Priority == 0 {
+			t.Priority = s.Priority
+		}
+
+		// enqueue task
+		t, err = svc.schedulerSvc.Enqueue(t, opts.UserId)
+		if err != nil {
+			return nil, err
+		}
+
+		// append task id
+		taskIds = append(taskIds, t.Id)
 	}
-	t2, err := svc.schedulerSvc.Enqueue(t, opts.UserId)
-	if err != nil {
-		return nil, err
-	}
-	taskIds = append(taskIds, t2.Id)
 
 	return taskIds, nil
 }
 
-func (svc *ServiceV2) getNodeIds(opts *interfaces.SpiderRunOptions) (nodeIds []primitive.ObjectID, err error) {
+func (svc *Service) getNodeIds(opts *interfaces.SpiderRunOptions) (nodeIds []primitive.ObjectID, err error) {
 	if opts.Mode == constants.RunTypeAllNodes {
 		query := bson.M{
 			"active":  true,
@@ -101,11 +104,15 @@ func (svc *ServiceV2) getNodeIds(opts *interfaces.SpiderRunOptions) (nodeIds []p
 		}
 	} else if opts.Mode == constants.RunTypeSelectedNodes {
 		nodeIds = opts.NodeIds
+	} else if opts.Mode == constants.RunTypeRandom {
+		nodeIds = []primitive.ObjectID{primitive.NilObjectID}
+	} else {
+		return nil, errors.New("invalid run mode")
 	}
 	return nodeIds, nil
 }
 
-func (svc *ServiceV2) isMultiTask(opts *interfaces.SpiderRunOptions) (res bool) {
+func (svc *Service) isMultiTask(opts *interfaces.SpiderRunOptions) (res bool) {
 	if opts.Mode == constants.RunTypeAllNodes {
 		query := bson.M{
 			"active":  true,
@@ -127,19 +134,16 @@ func (svc *ServiceV2) isMultiTask(opts *interfaces.SpiderRunOptions) (res bool)
 	}
 }
 
-func newSpiderAdminServiceV2() (svc2 *ServiceV2, err error) {
-	svc := &ServiceV2{
+func newSpiderAdminService() (svc2 *Service, err error) {
+	svc := &Service{
 		nodeCfgSvc: config.GetNodeConfigService(),
 		cfgPath:    config2.GetConfigPath(),
 	}
-	svc.schedulerSvc, err = scheduler.GetTaskSchedulerServiceV2()
+	svc.schedulerSvc, err = scheduler.GetTaskSchedulerService()
 	if err != nil {
 		return nil, err
 	}
 
-	// cron
-	svc.cron = cron.New()
-
 	// validate node type
 	if !svc.nodeCfgSvc.IsMaster() {
 		return nil, errors.New("only master node can run spider admin service")
@@ -148,21 +152,21 @@ func newSpiderAdminServiceV2() (svc2 *ServiceV2, err error) {
 	return svc, nil
 }
 
-var svcV2 *ServiceV2
-var svcV2Once = new(sync.Once)
+var svc *Service
+var svcOnce = new(sync.Once)
 
-func GetSpiderAdminServiceV2() (svc2 *ServiceV2, err error) {
-	if svcV2 != nil {
-		return svcV2, nil
+func GetSpiderAdminService() (svc2 *Service, err error) {
+	if svc != nil {
+		return svc, nil
 	}
-	svcV2Once.Do(func() {
-		svcV2, err = newSpiderAdminServiceV2()
+	svcOnce.Do(func() {
+		svc, err = newSpiderAdminService()
 		if err != nil {
-			log2.Errorf("[GetSpiderAdminServiceV2] error: %v", err)
+			log2.Errorf("[GetSpiderAdminService] error: %v", err)
 		}
 	})
 	if err != nil {
 		return nil, err
 	}
-	return svcV2, nil
+	return svc, nil
 }
diff --git a/core/task/handler/runner_v2.go b/core/task/handler/runner.go
similarity index 92%
rename from core/task/handler/runner_v2.go
rename to core/task/handler/runner.go
index 09f74d90..34fe048b 100644
--- a/core/task/handler/runner_v2.go
+++ b/core/task/handler/runner.go
@@ -33,7 +33,7 @@ import (
 	"time"
 )
 
-type RunnerV2 struct {
+type Runner struct {
 	// dependencies
 	svc   *Service             // task handler service
 	fsSvc interfaces.FsService // task fs service
@@ -48,7 +48,7 @@ type RunnerV2 struct {
 	tid  primitive.ObjectID             // task id
 	t    *models.TaskV2                 // task model.Task
 	s    *models.SpiderV2               // spider model.Spider
-	ch   chan constants.TaskSignal      // channel to communicate between Service and RunnerV2
+	ch   chan constants.TaskSignal      // channel to communicate between Service and Runner
 	err  error                          // standard process error
 	cwd  string                         // working directory
 	c    *client2.GrpcClient            // grpc client
@@ -60,7 +60,7 @@ type RunnerV2 struct {
 	logBatchSize  int
 }
 
-func (r *RunnerV2) Init() (err error) {
+func (r *Runner) Init() (err error) {
 	// update task
 	if err := r.updateTask("", nil); err != nil {
 		return err
@@ -82,7 +82,7 @@ func (r *RunnerV2) Init() (err error) {
 	return nil
 }
 
-func (r *RunnerV2) Run() (err error) {
+func (r *Runner) Run() (err error) {
 	// log task started
 	log.Infof("task[%s] started", r.tid.Hex())
 
@@ -165,7 +165,7 @@ func (r *RunnerV2) Run() (err error) {
 	return err
 }
 
-func (r *RunnerV2) Cancel(force bool) (err error) {
+func (r *Runner) Cancel(force bool) (err error) {
 	// kill process
 	opts := &sys_exec.KillProcessOptions{
 		Timeout: r.svc.GetCancelTimeout(),
@@ -191,15 +191,15 @@ func (r *RunnerV2) Cancel(force bool) (err error) {
 	}
 }
 
-func (r *RunnerV2) SetSubscribeTimeout(timeout time.Duration) {
+func (r *Runner) SetSubscribeTimeout(timeout time.Duration) {
 	r.subscribeTimeout = timeout
 }
 
-func (r *RunnerV2) GetTaskId() (id primitive.ObjectID) {
+func (r *Runner) GetTaskId() (id primitive.ObjectID) {
 	return r.tid
 }
 
-func (r *RunnerV2) configureCmd() (err error) {
+func (r *Runner) configureCmd() (err error) {
 	var cmdStr string
 
 	// customized spider
@@ -230,7 +230,7 @@ func (r *RunnerV2) configureCmd() (err error) {
 	return nil
 }
 
-func (r *RunnerV2) configureLogging() {
+func (r *Runner) configureLogging() {
 	// set stdout reader
 	stdout, _ := r.cmd.StdoutPipe()
 	r.scannerStdout = bufio.NewReaderSize(stdout, r.bufferSize)
@@ -240,7 +240,7 @@ func (r *RunnerV2) configureLogging() {
 	r.scannerStderr = bufio.NewReaderSize(stderr, r.bufferSize)
 }
 
-func (r *RunnerV2) startLogging() {
+func (r *Runner) startLogging() {
 	// start reading stdout
 	go r.startLoggingReaderStdout()
 
@@ -248,7 +248,7 @@ func (r *RunnerV2) startLogging() {
 	go r.startLoggingReaderStderr()
 }
 
-func (r *RunnerV2) startLoggingReaderStdout() {
+func (r *Runner) startLoggingReaderStdout() {
 	for {
 		line, err := r.scannerStdout.ReadString(byte('\n'))
 		if err != nil {
@@ -259,7 +259,7 @@ func (r *RunnerV2) startLoggingReaderStdout() {
 	}
 }
 
-func (r *RunnerV2) startLoggingReaderStderr() {
+func (r *Runner) startLoggingReaderStderr() {
 	for {
 		line, err := r.scannerStderr.ReadString(byte('\n'))
 		if err != nil {
@@ -270,7 +270,7 @@ func (r *RunnerV2) startLoggingReaderStderr() {
 	}
 }
 
-func (r *RunnerV2) startHealthCheck() {
+func (r *Runner) startHealthCheck() {
 	if r.cmd.ProcessState == nil || r.cmd.ProcessState.Exited() {
 		return
 	}
@@ -285,7 +285,7 @@ func (r *RunnerV2) startHealthCheck() {
 	}
 }
 
-func (r *RunnerV2) configureEnv() {
+func (r *Runner) configureEnv() {
 	// 默认把Node.js的全局node_modules加入环境变量
 	envPath := os.Getenv("PATH")
 	nodePath := "/usr/lib/node_modules"
@@ -316,7 +316,7 @@ func (r *RunnerV2) configureEnv() {
 	}
 }
 
-func (r *RunnerV2) syncFiles() (err error) {
+func (r *Runner) syncFiles() (err error) {
 	var id string
 	var workingDir string
 	if r.s.GitId.IsZero() {
@@ -425,7 +425,7 @@ func (r *RunnerV2) syncFiles() (err error) {
 	return err
 }
 
-func (r *RunnerV2) downloadFile(url string, filePath string, fileInfo *entity.FsFileInfo) error {
+func (r *Runner) downloadFile(url string, filePath string, fileInfo *entity.FsFileInfo) error {
 	// get file response
 	resp, err := http.Get(url)
 	if err != nil {
@@ -465,8 +465,8 @@ func (r *RunnerV2) downloadFile(url string, filePath string, fileInfo *entity.Fs
 }
 
 // wait for process to finish and send task signal (constants.TaskSignal)
-// to task runner's channel (RunnerV2.ch) according to exit code
-func (r *RunnerV2) wait() {
+// to task runner's channel (Runner.ch) according to exit code
+func (r *Runner) wait() {
 	// wait for process to finish
 	if err := r.cmd.Wait(); err != nil {
 		var exitError *exec.ExitError
@@ -492,8 +492,8 @@ func (r *RunnerV2) wait() {
 	r.ch <- constants.TaskSignalFinish
 }
 
-// updateTask update and get updated info of task (RunnerV2.t)
-func (r *RunnerV2) updateTask(status string, e error) (err error) {
+// updateTask update and get updated info of task (Runner.t)
+func (r *Runner) updateTask(status string, e error) (err error) {
 	if r.t != nil && status != "" {
 		// update task status
 		r.t.Status = status
@@ -529,7 +529,7 @@ func (r *RunnerV2) updateTask(status string, e error) (err error) {
 	return nil
 }
 
-func (r *RunnerV2) initConnection() (err error) {
+func (r *Runner) initConnection() (err error) {
 	r.conn, err = r.c.TaskClient.Connect(context.Background())
 	if err != nil {
 		return trace.TraceError(err)
@@ -537,7 +537,7 @@ func (r *RunnerV2) initConnection() (err error) {
 	return nil
 }
 
-func (r *RunnerV2) writeLogLines(lines []string) {
+func (r *Runner) writeLogLines(lines []string) {
 	linesBytes, err := json.Marshal(lines)
 	if err != nil {
 		log.Errorf("Error marshaling log lines: %v", err)
@@ -554,7 +554,7 @@ func (r *RunnerV2) writeLogLines(lines []string) {
 	}
 }
 
-func (r *RunnerV2) _updateTaskStat(status string) {
+func (r *Runner) _updateTaskStat(status string) {
 	ts, err := client.NewModelServiceV2[models.TaskStatV2]().GetById(r.tid)
 	if err != nil {
 		trace.PrintError(err)
@@ -590,7 +590,7 @@ func (r *RunnerV2) _updateTaskStat(status string) {
 	}
 }
 
-func (r *RunnerV2) sendNotification() {
+func (r *Runner) sendNotification() {
 	req := &grpc.TaskServiceSendNotificationRequest{
 		NodeKey: r.svc.GetNodeConfigService().GetNodeKey(),
 		TaskId:  r.tid.Hex(),
@@ -603,7 +603,7 @@ func (r *RunnerV2) sendNotification() {
 	}
 }
 
-func (r *RunnerV2) _updateSpiderStat(status string) {
+func (r *Runner) _updateSpiderStat(status string) {
 	// task stat
 	ts, err := client.NewModelServiceV2[models.TaskStatV2]().GetById(r.tid)
 	if err != nil {
@@ -657,7 +657,7 @@ func (r *RunnerV2) _updateSpiderStat(status string) {
 	}
 }
 
-func (r *RunnerV2) configureCwd() {
+func (r *Runner) configureCwd() {
 	workspacePath := viper.GetString("workspace")
 	if r.s.GitId.IsZero() {
 		// not git
@@ -668,14 +668,14 @@ func (r *RunnerV2) configureCwd() {
 	}
 }
 
-func NewTaskRunnerV2(id primitive.ObjectID, svc *Service) (r2 *RunnerV2, err error) {
+func NewTaskRunnerV2(id primitive.ObjectID, svc *Service) (r2 *Runner, err error) {
 	// validate options
 	if id.IsZero() {
 		return nil, constants.ErrInvalidOptions
 	}
 
 	// runner
-	r := &RunnerV2{
+	r := &Runner{
 		subscribeTimeout: 30 * time.Second,
 		bufferSize:       1024 * 1024,
 		svc:              svc,
diff --git a/core/task/handler/service.go b/core/task/handler/service.go
index e02c7c3a..001fbc71 100644
--- a/core/task/handler/service.go
+++ b/core/task/handler/service.go
@@ -51,8 +51,8 @@ func (svc *Service) Start() {
 		}
 	}
 
-	go svc.ReportStatus()
-	go svc.FetchAndRunTasks()
+	go svc.reportStatus()
+	go svc.fetchAndRunTasks()
 }
 
 func (svc *Service) Stop() {
@@ -67,7 +67,7 @@ func (svc *Service) Cancel(taskId primitive.ObjectID, force bool) (err error) {
 	return svc.cancelTask(taskId, force)
 }
 
-func (svc *Service) FetchAndRunTasks() {
+func (svc *Service) fetchAndRunTasks() {
 	ticker := time.NewTicker(svc.fetchInterval)
 	for {
 		if svc.stopped {
@@ -119,7 +119,7 @@ func (svc *Service) FetchAndRunTasks() {
 	}
 }
 
-func (svc *Service) ReportStatus() {
+func (svc *Service) reportStatus() {
 	ticker := time.NewTicker(svc.reportInterval)
 	for {
 		if svc.stopped {
@@ -128,9 +128,9 @@ func (svc *Service) ReportStatus() {
 
 		select {
 		case <-ticker.C:
-			// report handler status
-			if err := svc.reportStatus(); err != nil {
-				trace.PrintError(err)
+			// update node status
+			if err := svc.updateNodeStatus(); err != nil {
+				log.Errorf("failed to report status: %v", err)
 			}
 		}
 	}
@@ -178,6 +178,19 @@ func (svc *Service) GetTaskById(id primitive.ObjectID) (t *models2.TaskV2, err e
 	return t, nil
 }
 
+func (svc *Service) UpdateTask(t *models2.TaskV2) (err error) {
+	t.SetUpdated(t.CreatedBy)
+	if svc.cfgSvc.IsMaster() {
+		err = service.NewModelServiceV2[models2.TaskV2]().ReplaceById(t.Id, *t)
+	} else {
+		err = client.NewModelServiceV2[models2.TaskV2]().ReplaceById(t.Id, *t)
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func (svc *Service) GetSpiderById(id primitive.ObjectID) (s *models2.SpiderV2, err error) {
 	if svc.cfgSvc.IsMaster() {
 		s, err = service.NewModelServiceV2[models2.SpiderV2]().GetById(id)
@@ -194,12 +207,14 @@ func (svc *Service) GetSpiderById(id primitive.ObjectID) (s *models2.SpiderV2, e
 func (svc *Service) getRunnerCount() (count int) {
 	n, err := svc.GetCurrentNode()
 	if err != nil {
-		trace.PrintError(err)
+		log.Errorf("failed to get current node: %v", err)
 		return
 	}
 	query := bson.M{
 		"node_id": n.Id,
-		"status":  constants.TaskStatusRunning,
+		"status": bson.M{
+			"$in": []string{constants.TaskStatusAssigned, constants.TaskStatusRunning},
+		},
 	}
 	if svc.cfgSvc.IsMaster() {
 		count, err = service.NewModelServiceV2[models2.TaskV2]().Count(query)
@@ -242,7 +257,7 @@ func (svc *Service) deleteRunner(taskId primitive.ObjectID) {
 	svc.runners.Delete(taskId)
 }
 
-func (svc *Service) reportStatus() (err error) {
+func (svc *Service) updateNodeStatus() (err error) {
 	// current node
 	n, err := svc.GetCurrentNode()
 	if err != nil {
@@ -398,8 +413,19 @@ func (svc *Service) handleCancel(msg *grpc.TaskServiceSubscribeResponse, taskId
 		log.Errorf("task[%s] failed to cancel: %v", taskId.Hex(), err)
 		return
 	}
-
 	log.Infof("task[%s] cancelled", taskId.Hex())
+
+	// set task status as "cancelled"
+	t, err := svc.GetTaskById(taskId)
+	if err != nil {
+		log.Errorf("task[%s] failed to get task: %v", taskId.Hex(), err)
+		return
+	}
+	t.Status = constants.TaskStatusCancelled
+	err = svc.UpdateTask(t)
+	if err != nil {
+		log.Errorf("task[%s] failed to update task: %v", taskId.Hex(), err)
+	}
 }
 
 func (svc *Service) cancelTask(taskId primitive.ObjectID, force bool) (err error) {
diff --git a/core/task/scheduler/service_v2.go b/core/task/scheduler/service.go
similarity index 75%
rename from core/task/scheduler/service_v2.go
rename to core/task/scheduler/service.go
index a97760d9..c739c870 100644
--- a/core/task/scheduler/service_v2.go
+++ b/core/task/scheduler/service.go
@@ -21,7 +21,7 @@ import (
 	"time"
 )
 
-type ServiceV2 struct {
+type Service struct {
 	// dependencies
 	nodeCfgSvc interfaces.NodeConfigService
 	svr        *server.GrpcServer
@@ -31,13 +31,13 @@ type ServiceV2 struct {
 	interval time.Duration
 }
 
-func (svc *ServiceV2) Start() {
+func (svc *Service) Start() {
 	go svc.initTaskStatus()
 	go svc.cleanupTasks()
 	utils.DefaultWait()
 }
 
-func (svc *ServiceV2) Enqueue(t *models2.TaskV2, by primitive.ObjectID) (t2 *models2.TaskV2, err error) {
+func (svc *Service) Enqueue(t *models2.TaskV2, by primitive.ObjectID) (t2 *models2.TaskV2, err error) {
 	// set task status
 	t.Status = constants.TaskStatusPending
 	t.SetCreated(by)
@@ -45,32 +45,17 @@ func (svc *ServiceV2) Enqueue(t *models2.TaskV2, by primitive.ObjectID) (t2 *mod
 
 	// add task
 	taskModelSvc := service.NewModelServiceV2[models2.TaskV2]()
-	id, err := taskModelSvc.InsertOne(*t)
+	t.Id, err = taskModelSvc.InsertOne(*t)
 	if err != nil {
 		return nil, err
 	}
 
-	// task queue item
-	tq := models2.TaskQueueItemV2{
-		Priority: t.Priority,
-		NodeId:   t.NodeId,
-	}
-	tq.SetId(id)
-	tq.SetCreated(by)
-	tq.SetUpdated(by)
-
 	// task stat
 	ts := models2.TaskStatV2{}
-	ts.SetId(id)
+	ts.SetId(t.Id)
 	ts.SetCreated(by)
 	ts.SetUpdated(by)
 
-	// enqueue task
-	_, err = service.NewModelServiceV2[models2.TaskQueueItemV2]().InsertOne(tq)
-	if err != nil {
-		return nil, trace.TraceError(err)
-	}
-
 	// add task stat
 	_, err = service.NewModelServiceV2[models2.TaskStatV2]().InsertOne(ts)
 	if err != nil {
@@ -81,7 +66,7 @@ func (svc *ServiceV2) Enqueue(t *models2.TaskV2, by primitive.ObjectID) (t2 *mod
 	return t, nil
 }
 
-func (svc *ServiceV2) Cancel(id, by primitive.ObjectID, force bool) (err error) {
+func (svc *Service) Cancel(id, by primitive.ObjectID, force bool) (err error) {
 	// task
 	t, err := service.NewModelServiceV2[models2.TaskV2]().GetById(id)
 	if err != nil {
@@ -92,14 +77,10 @@ func (svc *ServiceV2) Cancel(id, by primitive.ObjectID, force bool) (err error)
 	// initial status
 	initialStatus := t.Status
 
-	// set status of pending tasks as "cancelled" and remove from task item queue
+	// set status of pending tasks as "cancelled"
 	if initialStatus == constants.TaskStatusPending {
-		// remove from task item queue
-		if err := service.NewModelServiceV2[models2.TaskQueueItemV2]().DeleteById(t.Id); err != nil {
-			log.Errorf("failed to delete task queue item: %s", t.Id.Hex())
-			return err
-		}
-		return nil
+		t.Status = constants.TaskStatusCancelled
+		return svc.SaveTask(t, by)
 	}
 
 	// whether task is running on master node
@@ -120,7 +101,7 @@ func (svc *ServiceV2) Cancel(id, by primitive.ObjectID, force bool) (err error)
 	}
 }
 
-func (svc *ServiceV2) cancelOnMaster(t *models2.TaskV2, by primitive.ObjectID, force bool) (err error) {
+func (svc *Service) cancelOnMaster(t *models2.TaskV2, by primitive.ObjectID, force bool) (err error) {
 	if err := svc.handlerSvc.Cancel(t.Id, force); err != nil {
 		log.Errorf("failed to cancel task on master: %s", t.Id.Hex())
 		return err
@@ -131,7 +112,7 @@ func (svc *ServiceV2) cancelOnMaster(t *models2.TaskV2, by primitive.ObjectID, f
 	return svc.SaveTask(t, by)
 }
 
-func (svc *ServiceV2) cancelOnWorker(t *models2.TaskV2, by primitive.ObjectID, force bool) (err error) {
+func (svc *Service) cancelOnWorker(t *models2.TaskV2, by primitive.ObjectID, force bool) (err error) {
 	// get subscribe stream
 	stream, ok := svc.svr.TaskSvr.GetSubscribeStream(t.Id)
 	if !ok {
@@ -156,11 +137,11 @@ func (svc *ServiceV2) cancelOnWorker(t *models2.TaskV2, by primitive.ObjectID, f
 	return nil
 }
 
-func (svc *ServiceV2) SetInterval(interval time.Duration) {
+func (svc *Service) SetInterval(interval time.Duration) {
 	svc.interval = interval
 }
 
-func (svc *ServiceV2) SaveTask(t *models2.TaskV2, by primitive.ObjectID) (err error) {
+func (svc *Service) SaveTask(t *models2.TaskV2, by primitive.ObjectID) (err error) {
 	if t.Id.IsZero() {
 		t.SetCreated(by)
 		t.SetUpdated(by)
@@ -173,12 +154,13 @@ func (svc *ServiceV2) SaveTask(t *models2.TaskV2, by primitive.ObjectID) (err er
 }
 
 // initTaskStatus initialize task status of existing tasks
-func (svc *ServiceV2) initTaskStatus() {
+func (svc *Service) initTaskStatus() {
 	// set status of running tasks as TaskStatusAbnormal
 	runningTasks, err := service.NewModelServiceV2[models2.TaskV2]().GetMany(bson.M{
 		"status": bson.M{
 			"$in": []string{
 				constants.TaskStatusPending,
+				constants.TaskStatusAssigned,
 				constants.TaskStatusRunning,
 			},
 		},
@@ -187,7 +169,8 @@ func (svc *ServiceV2) initTaskStatus() {
 		if errors2.Is(err, mongo2.ErrNoDocuments) {
 			return
 		}
-		trace.PrintError(err)
+		log.Errorf("failed to get running tasks: %v", err)
+		return
 	}
 	for _, t := range runningTasks {
 		go func(t *models2.TaskV2) {
@@ -197,12 +180,9 @@ func (svc *ServiceV2) initTaskStatus() {
 			}
 		}(&t)
 	}
-	if err := service.NewModelServiceV2[models2.TaskQueueItemV2]().DeleteMany(nil); err != nil {
-		return
-	}
 }
 
-func (svc *ServiceV2) isMasterNode(t *models2.TaskV2) (ok bool, err error) {
+func (svc *Service) isMasterNode(t *models2.TaskV2) (ok bool, err error) {
 	if t.NodeId.IsZero() {
 		return false, trace.TraceError(errors.ErrorTaskNoNodeId)
 	}
@@ -216,7 +196,7 @@ func (svc *ServiceV2) isMasterNode(t *models2.TaskV2) (ok bool, err error) {
 	return n.IsMaster, nil
 }
 
-func (svc *ServiceV2) cleanupTasks() {
+func (svc *Service) cleanupTasks() {
 	for {
 		// task stats over 30 days ago
 		taskStats, err := service.NewModelServiceV2[models2.TaskStatV2]().GetMany(bson.M{
@@ -255,9 +235,9 @@ func (svc *ServiceV2) cleanupTasks() {
 	}
 }
 
-func NewTaskSchedulerServiceV2() (svc2 *ServiceV2, err error) {
+func NewTaskSchedulerService() (svc2 *Service, err error) {
 	// service
-	svc := &ServiceV2{
+	svc := &Service{
 		interval: 5 * time.Second,
 	}
 	svc.nodeCfgSvc = nodeconfig.GetNodeConfigService()
@@ -275,15 +255,15 @@ func NewTaskSchedulerServiceV2() (svc2 *ServiceV2, err error) {
 	return svc, nil
 }
 
-var svcV2 *ServiceV2
+var svc *Service
 
-func GetTaskSchedulerServiceV2() (svr *ServiceV2, err error) {
-	if svcV2 != nil {
-		return svcV2, nil
+func GetTaskSchedulerService() (svr *Service, err error) {
+	if svc != nil {
+		return svc, nil
 	}
-	svcV2, err = NewTaskSchedulerServiceV2()
+	svc, err = NewTaskSchedulerService()
 	if err != nil {
 		return nil, err
 	}
-	return svcV2, nil
+	return svc, nil
 }