diff --git a/commons/pcap/pcap.go b/commons/pcap/pcap.go
index 839d9ce..e865d5b 100644
--- a/commons/pcap/pcap.go
+++ b/commons/pcap/pcap.go
@@ -33,18 +33,20 @@ func RetainScanner(zone *model.Zone) (PCapScanner, error) {
 }
 
 func ReleaseScanner(zone *model.Zone) {
-	mtx.Lock()
-	defer mtx.Unlock()
 
-	if ps, ok := instances[zone.Network]; ok {
-		go func() {
-			time.Sleep(2 * time.Second)
+	go func() {
+		time.Sleep(2 * time.Second)
+
+		mtx.Lock()
+		defer mtx.Unlock()
+
+		if ps, ok := instances[zone.Network]; ok {
 			if ps.release() {
 				ps.stop()
 				delete(instances, zone.Network)
 			}
-		}()
-	}
+		}
+	}()
 }
 
 func ReleaseScannerAll() {
diff --git a/discovery/discovery.go b/discovery/discovery.go
index d47ec3d..7ef4c99 100644
--- a/discovery/discovery.go
+++ b/discovery/discovery.go
@@ -73,9 +73,9 @@ func (d *discovery) stop() {
 }
 
 func (d *discovery) discoverZone(dz *model.DiscoveryZone) {
-	taskScan(d,
-		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}) {
-			scanZone(dz, resultChan, errChan, doneChan)
+	go taskScan(d,
+		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}, stopChan chan struct{}) {
+			scanZone(dz, resultChan, errChan, doneChan, stopChan)
 		},
 		func(result interface{}) {
 			z := result.(*model.Zone)
@@ -94,9 +94,9 @@ func (d *discovery) discoverZone(dz *model.DiscoveryZone) {
 }
 
 func (d *discovery) discoverHost(zone *model.Zone, dh *model.DiscoveryHost) {
-	taskScan(d,
-		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}) {
-			scanHost(zone, dh, resultChan, errChan, doneChan)
+	go taskScan(d,
+		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}, stopChan chan struct{}) {
+			scanHost(zone, dh, resultChan, errChan, doneChan, stopChan)
 		},
 		func(result interface{}) {
 			h := result.(*model.Host)
@@ -109,9 +109,9 @@ func (d *discovery) discoverHost(zone *model.Zone, dh *model.DiscoveryHost) {
 }
 
 func (d *discovery) discoverPort(host *model.Host, dp *model.DiscoveryPort) {
-	taskScan(d,
-		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}) {
-			scanPort(host, dp, resultChan, errChan, doneChan)
+	go taskScan(d,
+		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}, stopChan chan struct{}) {
+			scanPort(host, dp, resultChan, errChan, doneChan, stopChan)
 		},
 		func(result interface{}) {
 			p := result.(*model.Port)
@@ -124,9 +124,9 @@ func (d *discovery) discoverPort(host *model.Host, dp *model.DiscoveryPort) {
 }
 
 func (d *discovery) discoverService(port *model.Port, ds *model.DiscoveryService) {
-	taskScan(d,
-		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}) {
-			scanService(port, ds, resultChan, errChan, doneChan)
+	go taskScan(d,
+		func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}, stopChan chan struct{}) {
+			scanService(port, ds, resultChan, errChan, doneChan, stopChan)
 		},
 		func(result interface{}) {
 			s := result.(*model.Service)
@@ -143,20 +143,22 @@ func (d *discovery) sendError() {
 
 }
 
-func taskScan(d *discovery, task func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}), onResult func(result interface{})) {
+func taskScan(d *discovery, task func(resultChan chan interface{}, errChan chan error, doneChan chan struct{}, stopChan chan struct{}), onResult func(result interface{})) {
 	d.stopWg.Add(1)
 	resultChan := make(chan interface{})
 	errChan := make(chan error)
+	stopChan := make(chan struct{})
 	doneChan := make(chan struct{})
 
 	defer func() {
 		close(resultChan)
 		close(errChan)
+		close(stopChan)
 		close(doneChan)
 		d.stopWg.Done()
 	}()
 
-	go task(resultChan, errChan, doneChan)
+	go task(resultChan, errChan, doneChan, stopChan)
 
 	for {
 		select {
@@ -168,6 +170,8 @@ func taskScan(d *discovery, task func(resultChan chan interface{}, errChan chan
 			logging.Logger().Debug(fmt.Sprintf("Discovery: task is complete"))
 			return
 		case <-d.stopChan:
+			close(stopChan)
+			<-doneChan
 			return
 		}
 	}
diff --git a/discovery/host.go b/discovery/host.go
index 086aa25..fbc0dc8 100644
--- a/discovery/host.go
+++ b/discovery/host.go
@@ -9,22 +9,24 @@ import (
 	"git.loafle.net/overflow/overflow_discovery/discovery/ipv6"
 )
 
-func scanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
+func scanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}, stopChan chan struct{}) {
+	defer func() {
+		doneChan <- struct{}{}
+	}()
+
 	_, ipNet, err := net.ParseCIDR(zone.Network)
 	if nil != err {
 		errChan <- err
-		doneChan <- struct{}{}
 		return
 	}
 	switch len(ipNet.IP) {
 	case net.IPv4len:
-		ipv4.ScanHost(zone, dh, resultChan, errChan, doneChan)
+		ipv4.ScanHost(zone, dh, resultChan, errChan, stopChan)
 	case net.IPv6len:
-		ipv6.ScanHost(zone, dh, resultChan, errChan, doneChan)
+		ipv6.ScanHost(zone, dh, resultChan, errChan, stopChan)
 
 	default:
 		errChan <- fmt.Errorf("Discovery: Not supported ip length")
-		doneChan <- struct{}{}
 		return
 	}
 }
diff --git a/discovery/ipv4/host.go b/discovery/ipv4/host.go
index 642099b..9f5911e 100644
--- a/discovery/ipv4/host.go
+++ b/discovery/ipv4/host.go
@@ -14,11 +14,7 @@ import (
 	"git.loafle.net/overflow/overflow_discovery/commons/pcap"
 )
 
-func ScanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
-	defer func() {
-		doneChan <- struct{}{}
-	}()
-
+func ScanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interface{}, errChan chan error, stopChan chan struct{}) {
 	ps, err := pcap.RetainScanner(zone)
 	if nil != err {
 		errChan <- fmt.Errorf("Discovery: Cannot retain pcap instance %v", err)
@@ -58,11 +54,13 @@ func ScanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interfa
 				if h := handlePacketARP(zone, cr, hosts, packet); nil != h {
 					logging.Logger().Debug(fmt.Sprintf("Discovery: Host[%v] is founded", h))
 				}
+			case <-stopChan:
+				return
 			}
 		}
 	}()
 
-	if err := sendARP(ps, zone, hostRanges); nil != err {
+	if err := sendARP(ps, zone, hostRanges, stopChan); nil != err {
 		errChan <- err
 		return
 	}
@@ -91,7 +89,7 @@ func handlePacketARP(zone *model.Zone, cr cidr.CIDRRanger, hosts map[string]*mod
 	return h
 }
 
-func sendARP(ps pcap.PCapScanner, zone *model.Zone, hostRanges []net.IP) error {
+func sendARP(ps pcap.PCapScanner, zone *model.Zone, hostRanges []net.IP, stopChan chan struct{}) error {
 	hwAddr, err := net.ParseMAC(zone.Mac)
 	if nil != err {
 		return err
@@ -113,6 +111,13 @@ func sendARP(ps pcap.PCapScanner, zone *model.Zone, hostRanges []net.IP) error {
 		if err := ps.WritePacketData(buf.Bytes()); err != nil {
 			return err
 		}
+
+		select {
+		case <-stopChan:
+			return nil
+		default:
+		}
+
 		time.Sleep(time.Microsecond * 100)
 	}
 	return nil
diff --git a/discovery/ipv4/port.go b/discovery/ipv4/port.go
index 11f7999..ba53dd8 100644
--- a/discovery/ipv4/port.go
+++ b/discovery/ipv4/port.go
@@ -2,6 +2,6 @@ package ipv4
 
 import "git.loafle.net/overflow/overflow_discovery/api/module/discovery/model"
 
-func ScanPort(host *model.Host, dp *model.DiscoveryPort, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
+func ScanPort(host *model.Host, dp *model.DiscoveryPort, resultChan chan interface{}, errChan chan error, stopChan chan struct{}) {
 
 }
diff --git a/discovery/ipv6/host.go b/discovery/ipv6/host.go
index 357cd02..9a9905a 100644
--- a/discovery/ipv6/host.go
+++ b/discovery/ipv6/host.go
@@ -2,6 +2,6 @@ package ipv6
 
 import "git.loafle.net/overflow/overflow_discovery/api/module/discovery/model"
 
-func ScanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
+func ScanHost(zone *model.Zone, dh *model.DiscoveryHost, resultChan chan interface{}, errChan chan error, stopChan chan struct{}) {
 
 }
diff --git a/discovery/ipv6/port.go b/discovery/ipv6/port.go
index e4332c1..fd22582 100644
--- a/discovery/ipv6/port.go
+++ b/discovery/ipv6/port.go
@@ -2,6 +2,6 @@ package ipv6
 
 import "git.loafle.net/overflow/overflow_discovery/api/module/discovery/model"
 
-func ScanPort(host *model.Host, dp *model.DiscoveryPort, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
+func ScanPort(host *model.Host, dp *model.DiscoveryPort, resultChan chan interface{}, errChan chan error, stopChan chan struct{}) {
 
 }
diff --git a/discovery/port.go b/discovery/port.go
index ef0459f..ba4af2a 100644
--- a/discovery/port.go
+++ b/discovery/port.go
@@ -9,22 +9,24 @@ import (
 	"git.loafle.net/overflow/overflow_discovery/discovery/ipv6"
 )
 
-func scanPort(host *model.Host, dp *model.DiscoveryPort, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
+func scanPort(host *model.Host, dp *model.DiscoveryPort, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}, stopChan chan struct{}) {
+	defer func() {
+		doneChan <- struct{}{}
+	}()
+
 	_, ipNet, err := net.ParseCIDR(host.Zone.Network)
 	if nil != err {
 		errChan <- err
-		doneChan <- struct{}{}
 		return
 	}
 	switch len(ipNet.IP) {
 	case net.IPv4len:
-		ipv4.ScanPort(host, dp, resultChan, errChan, doneChan)
+		ipv4.ScanPort(host, dp, resultChan, errChan, stopChan)
 	case net.IPv6len:
-		ipv6.ScanPort(host, dp, resultChan, errChan, doneChan)
+		ipv6.ScanPort(host, dp, resultChan, errChan, stopChan)
 
 	default:
 		errChan <- fmt.Errorf("Discovery: Not supported ip length")
-		doneChan <- struct{}{}
 		return
 	}
 }
diff --git a/discovery/service.go b/discovery/service.go
index 8f9b3e0..6df7389 100644
--- a/discovery/service.go
+++ b/discovery/service.go
@@ -2,6 +2,9 @@ package discovery
 
 import "git.loafle.net/overflow/overflow_discovery/api/module/discovery/model"
 
-func scanService(port *model.Port, ds *model.DiscoveryService, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
-	doneChan <- struct{}{}
+func scanService(port *model.Port, ds *model.DiscoveryService, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}, stopChan chan struct{}) {
+	defer func() {
+		doneChan <- struct{}{}
+	}()
+
 }
diff --git a/discovery/zone.go b/discovery/zone.go
index d325247..0677b6f 100644
--- a/discovery/zone.go
+++ b/discovery/zone.go
@@ -8,7 +8,11 @@ import (
 	"git.loafle.net/overflow/overflow_discovery/api/module/discovery/model"
 )
 
-func scanZone(dz *model.DiscoveryZone, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}) {
+func scanZone(dz *model.DiscoveryZone, resultChan chan interface{}, errChan chan error, doneChan chan<- struct{}, stopChan chan struct{}) {
+	defer func() {
+		doneChan <- struct{}{}
+	}()
+
 	var err error
 	var ifaces []net.Interface
 	var addrs []net.Addr
@@ -58,9 +62,6 @@ func scanZone(dz *model.DiscoveryZone, resultChan chan interface{}, errChan chan
 			resultChan <- z
 		}
 	}
-
-	doneChan <- struct{}{}
-
 }
 
 func checkExclude(ep []string, iface string) bool {