diff --git a/server.go b/server.go
index 4bf04e0..343b77e 100644
--- a/server.go
+++ b/server.go
@@ -220,6 +220,22 @@ type Config struct {
 	//
 	// If unset or nil, the group aggregation feature will be disabled on the server.
 	GroupAggregator GroupAggregator
+
+	// HeartbeatInterval specifies the interval between heartbeats.
+	//
+	// If unset or zero, the interval is set to 5 seconds.
+	HeartbeatInterval time.Duration
+
+	// RecoverInterval specifies the interval between recovers.
+	//
+	// If unset or zero, the interval is set to 60 seconds.
+	RecoverInterval time.Duration
+
+	// JanitorInterval specifies the interval between Janitors.
+	//
+	// If unset or zero, the interval is set to 8 seconds.
+	JanitorInterval time.Duration
+
 }
 
 // GroupAggregator aggregates a group of tasks into one before the tasks are passed to the Handler.
@@ -242,7 +258,7 @@ func (fn GroupAggregatorFunc) Aggregate(group string, tasks []*Task) *Task {
 	return fn(group, tasks)
 }
 
-// An ErrorHandler handles an error occurred during task processing.
+// An ErrorHandler handles an error occured during task processing.
 type ErrorHandler interface {
 	HandleError(ctx context.Context, task *Task, err error)
 }
@@ -387,6 +403,13 @@ const (
 	defaultDelayedTaskCheckInterval = 5 * time.Second
 
 	defaultGroupGracePeriod = 1 * time.Minute
+
+	defaultHeartbeatInterval = 5 * time.Second
+
+	defaultRecoverInterval = 1 * time.Minute
+
+	defaultJanitorInterval = 8 * time.Second
+
 )
 
 // NewServer returns a new Server given a redis connection option
@@ -463,10 +486,14 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 		requestsCh: syncCh,
 		interval:   5 * time.Second,
 	})
+	heartbeatInterval := cfg.HeartbeatInterval
+	if heartbeatInterval == 0 {
+		heartbeatInterval = defaultHeartbeatInterval
+	}
 	heartbeater := newHeartbeater(heartbeaterParams{
 		logger:         logger,
 		broker:         rdb,
-		interval:       5 * time.Second,
+		interval:       heartbeatInterval,
 		concurrency:    n,
 		queues:         queues,
 		strictPriority: cfg.StrictPriority,
@@ -505,13 +532,17 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 		starting:        starting,
 		finished:        finished,
 	})
+	recoverInterval := cfg.RecoverInterval
+	if recoverInterval == 0 {
+		recoverInterval = defaultRecoverInterval
+	}
 	recoverer := newRecoverer(recovererParams{
 		logger:         logger,
 		broker:         rdb,
 		retryDelayFunc: delayFunc,
 		isFailureFunc:  isFailureFunc,
 		queues:         qnames,
-		interval:       1 * time.Minute,
+		interval:       recoverInterval,
 	})
 	healthchecker := newHealthChecker(healthcheckerParams{
 		logger:          logger,
@@ -519,11 +550,15 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 		interval:        healthcheckInterval,
 		healthcheckFunc: cfg.HealthCheckFunc,
 	})
+	janitorInterval := cfg.JanitorInterval
+	if janitorInterval == 0 {
+		janitorInterval = defaultJanitorInterval
+	}
 	janitor := newJanitor(janitorParams{
 		logger:   logger,
 		broker:   rdb,
 		queues:   qnames,
-		interval: 8 * time.Second,
+		interval: janitorInterval,
 	})
 	aggregator := newAggregator(aggregatorParams{
 		logger:          logger,
@@ -615,14 +650,31 @@ func (srv *Server) Start(handler Handler) error {
 	}
 	srv.logger.Info("Starting processing")
 
+	//周期向redis更新状态
 	srv.heartbeater.start(&srv.wg)
+
+	//周期ping redis
 	srv.healthchecker.start(&srv.wg)
+
+	//监听取消命令？
 	srv.subscriber.start(&srv.wg)
+
+	//周期？清理过期请求？
 	srv.syncer.start(&srv.wg)
+
+	//active任务转换成retry
 	srv.recoverer.start(&srv.wg)
+
+	//retry和schedule任务转换成pending任务
 	srv.forwarder.start(&srv.wg)
+
+	//开启一个worker处理任务
 	srv.processor.start(&srv.wg)
+
+	//删除过期任务
 	srv.janitor.start(&srv.wg)
+
+	//？
 	srv.aggregator.start(&srv.wg)
 	return nil
 }