diff --git a/src/pool_seg.go b/src/pool_seg.go
index b746cf1..ee8a905 100644
--- a/src/pool_seg.go
+++ b/src/pool_seg.go
@@ -7,5 +7,4 @@ type PoolSeg struct {
 	Nodes     map[string]*NodeStatus
 	Lock      sync.Mutex
 	Next      *PoolSeg
-	IsVirtual bool
 }
diff --git a/src/resource_pool.go b/src/resource_pool.go
index 5f01eca..4d16c4a 100644
--- a/src/resource_pool.go
+++ b/src/resource_pool.go
@@ -87,11 +87,7 @@ func (pool *ResourcePool) init(conf Configuration) {
 	/* init pools */
 	pool.poolsCount = 300
 	for i := 0; i < pool.poolsCount; i++ {
-		pool.pools = append(pool.pools, PoolSeg{Lock: sync.Mutex{}, IsVirtual: true, ID: i})
-	}
-	/* make non-virtual segs */
-	for i := 0; i < pool.poolsCount/3; i++ {
-		pool.pools[rand.Intn(pool.poolsCount)].IsVirtual = false
+		pool.pools = append(pool.pools, PoolSeg{Lock: sync.Mutex{}, ID: i})
 	}
 	/* generate working segs */
 	for i := 0; i < 10; i++ {
@@ -204,7 +200,10 @@ func (pool *ResourcePool) saveStatusHistory() {
 		AvailableMemGPU := 0
 		nodesCount := 0
 
-		start := pool.pools[0].Next
+		start := pool.pools[0]
+		if start.Nodes == nil {
+			start = *start.Next
+		}
 		for cur := start; ; {
 			cur.Lock.Lock()
 			for _, node := range cur.Nodes {
@@ -222,7 +221,7 @@ func (pool *ResourcePool) saveStatusHistory() {
 			}
 			nodesCount += len(cur.Nodes)
 			cur.Lock.Unlock()
-			cur = cur.Next
+			cur = *cur.Next
 			if cur.ID == start.ID {
 				break
 			}
@@ -295,8 +294,8 @@ func (pool *ResourcePool) update(node NodeStatus) {
 	pool.counterTotal++
 	pool.versionsMu.Lock()
 	if version, ok := pool.versions[node.ClientID]; ok && version == node.Version {
-		pool.versionsMu.Unlock()
-		return
+		//pool.versionsMu.Unlock()
+		//return
 	}
 	pool.versionsMu.Unlock()
 	pool.counter++
@@ -349,16 +348,15 @@ func (pool *ResourcePool) scaleSeg(seg *PoolSeg) {
 		/* find seg in the nearest middle */
 		minDistance := step
 		for i := 1; i < step; i++ {
-			if !pool.pools[(i+pre.ID)%pool.poolsCount].IsVirtual {
-				distance := i - step/2
-				if distance < 0 {
-					distance = -distance
-				}
-				if candidate == nil || distance < minDistance {
-					candidate = &pool.pools[i]
-					minDistance = distance
-				}
+			distance := i - step/2
+			if distance < 0 {
+				distance = -distance
 			}
+			if candidate == nil || distance < minDistance {
+				candidate = &pool.pools[i]
+				minDistance = distance
+			}
+
 		}
 
 		/* update Next */
@@ -417,15 +415,18 @@ func (pool *ResourcePool) getByID(id string) NodeStatus {
 func (pool *ResourcePool) list() MsgResource {
 	nodes := map[string]NodeStatus{}
 
-	start := pool.pools[0].Next
+	start := pool.pools[0]
+	if start.Nodes == nil {
+		start = *start.Next
+	}
 	for cur := start; ; {
 		cur.Lock.Lock()
 		for k, node := range cur.Nodes {
 			nodes[k] = *node
 		}
 		cur.Lock.Unlock()
-		cur = cur.Next
-		if cur == start {
+		cur = *cur.Next
+		if cur.ID == start.ID {
 			break
 		}
 	}
@@ -668,7 +669,7 @@ func (pool *ResourcePool) acquireResource(job Job) []NodeStatus {
 		allocationType = 1
 		if util, valid := InstanceOfOptimizer().predictUtilGPU(job.Name); valid {
 
-			for cur := start; cur.ID < cur.Next.ID; {
+			for cur := start; ; {
 				if _, ok := locks[cur.ID]; !ok {
 					cur.Lock.Lock()
 					locks[cur.ID] = &cur.Lock
@@ -705,10 +706,10 @@ func (pool *ResourcePool) acquireResource(job Job) []NodeStatus {
 				if len(candidates) >= len(job.Tasks)*3+5 {
 					break
 				}
-				cur = cur.Next
-				if cur.ID == start.ID {
+				if cur.ID > cur.Next.ID {
 					break
 				}
+				cur = cur.Next
 			}
 		}
 		//log.Info(candidates)
@@ -717,7 +718,7 @@ func (pool *ResourcePool) acquireResource(job Job) []NodeStatus {
 	/* second round, find vacant gpu */
 	if len(candidates) == 0 {
 		allocationType = 2
-		for cur := start; cur.ID < cur.Next.ID; {
+		for cur := start; ; {
 			if _, ok := locks[cur.ID]; !ok {
 				cur.Lock.Lock()
 				locks[cur.ID] = &cur.Lock
@@ -740,10 +741,10 @@ func (pool *ResourcePool) acquireResource(job Job) []NodeStatus {
 			if len(candidates) >= len(job.Tasks)*3+5 {
 				break
 			}
-			cur = cur.Next
-			if cur.ID == start.ID {
+			if cur.ID > cur.Next.ID {
 				break
 			}
+			cur = cur.Next
 		}
 		//log.Info(candidates)
 	}
@@ -758,7 +759,7 @@ func (pool *ResourcePool) acquireResource(job Job) []NodeStatus {
 
 		if pool.TotalGPU != 0 && float64(pool.UsingGPU)/float64(pool.TotalGPU) >= pool.enablePreScheduleRatio && valid {
 			allocationType = 3
-			for cur := start; cur.ID < cur.Next.ID; {
+			for cur := start; ; {
 				if _, ok := locks[cur.ID]; !ok {
 					cur.Lock.Lock()
 					locks[cur.ID] = &cur.Lock
@@ -794,6 +795,10 @@ func (pool *ResourcePool) acquireResource(job Job) []NodeStatus {
 				if len(candidates) >= len(job.Tasks)*3+5 {
 					break
 				}
+				if cur.ID > cur.Next.ID {
+					break
+				}
+				cur = cur.Next
 			}
 			//log.Info(candidates)
 		}
diff --git a/src/scheduler_capacity.go b/src/scheduler_capacity.go
index 9242a17..07b251c 100644
--- a/src/scheduler_capacity.go
+++ b/src/scheduler_capacity.go
@@ -31,8 +31,6 @@ type SchedulerCapacity struct {
 
 	queuesSchedulingCnt map[string]int
 	queuesUsingGPUMu    sync.Mutex
-
-	mu sync.Mutex
 }
 
 type FairJobSorter []Job
@@ -133,8 +131,6 @@ func (scheduler *SchedulerCapacity) Start() {
 				}()
 			} else {
 				log.Debug("No more jobs to scheduling ", time.Now())
-				scheduler.schedulingMu.Lock()
-				scheduler.schedulingMu.Unlock()
 			}
 			scheduler.queueMu.Unlock()
 		}