diff --git a/pkg/node/manytoone.go b/pkg/node/manytoone.go
index 6f02c742..2b5bbd33 100644
--- a/pkg/node/manytoone.go
+++ b/pkg/node/manytoone.go
@@ -96,8 +96,8 @@ func (n *ManyToOneNode) forward(index int) port.Listener {
 		defer n.mu.RUnlock()
 
 		inReader := n.inPorts[index].Open(proc)
-		outWriter := n.outPort.Open(proc)
-		errWriter := n.errPort.Open(proc)
+		var outWriter *packet.Writer
+		var errWriter *packet.Writer
 
 		readGroup, _ := n.readGroups.LoadOrStore(proc, func() (*packet.ReadGroup, error) {
 			inReaders := make([]*packet.Reader, len(n.inPorts))
@@ -110,6 +110,13 @@ func (n *ManyToOneNode) forward(index int) port.Listener {
 		for inPck := range inReader.Read() {
 			n.tracer.Read(inReader, inPck)
 
+			if outWriter == nil {
+				outWriter = n.outPort.Open(proc)
+			}
+			if errWriter == nil {
+				errWriter = n.errPort.Open(proc)
+			}
+
 			if inPcks := readGroup.Read(inReader, inPck); len(inPcks) < len(n.inPorts) {
 				n.tracer.Reduce(inPck)
 			} else if outPck, errPck := n.action(proc, inPcks); errPck != nil {
diff --git a/pkg/node/onetomany.go b/pkg/node/onetomany.go
index 48fef2a6..8e4d1cd5 100644
--- a/pkg/node/onetomany.go
+++ b/pkg/node/onetomany.go
@@ -94,15 +94,21 @@ func (n *OneToManyNode) forward(proc *process.Process) {
 	defer n.mu.RUnlock()
 
 	inReader := n.inPort.Open(proc)
-	outWriters := make([]*packet.Writer, len(n.outPorts))
-	for i, outPort := range n.outPorts {
-		outWriters[i] = outPort.Open(proc)
-	}
-	errWriter := n.errPort.Open(proc)
+	outWriters := make([]*packet.Writer, 0, len(n.outPorts))
+	var errWriter *packet.Writer
 
 	for inPck := range inReader.Read() {
 		n.tracer.Read(inReader, inPck)
 
+		if len(outWriters) == 0 {
+			for _, outPort := range n.outPorts {
+				outWriters = append(outWriters, outPort.Open(proc))
+			}
+		}
+		if errWriter == nil {
+			errWriter = n.errPort.Open(proc)
+		}
+
 		if outPcks, errPck := n.action(proc, inPck); errPck != nil {
 			n.tracer.Transform(inPck, errPck)
 			n.tracer.Write(errWriter, errPck)
diff --git a/pkg/node/onetoone.go b/pkg/node/onetoone.go
index f9773845..a78f933b 100644
--- a/pkg/node/onetoone.go
+++ b/pkg/node/onetoone.go
@@ -69,12 +69,19 @@ func (n *OneToOneNode) Close() error {
 
 func (n *OneToOneNode) forward(proc *process.Process) {
 	inReader := n.inPort.Open(proc)
-	outWriter := n.outPort.Open(proc)
-	errWriter := n.errPort.Open(proc)
+	var outWriter *packet.Writer
+	var errWriter *packet.Writer
 
 	for inPck := range inReader.Read() {
 		n.tracer.Read(inReader, inPck)
 
+		if outWriter == nil {
+			outWriter = n.outPort.Open(proc)
+		}
+		if errWriter == nil {
+			errWriter = n.errPort.Open(proc)
+		}
+
 		if outPck, errPck := n.action(proc, inPck); errPck != nil {
 			n.tracer.Transform(inPck, errPck)
 			n.tracer.Write(errWriter, errPck)
diff --git a/pkg/symbol/cluster.go b/pkg/symbol/cluster.go
index 261fe892..b0fb9c8c 100644
--- a/pkg/symbol/cluster.go
+++ b/pkg/symbol/cluster.go
@@ -1,6 +1,7 @@
 package symbol
 
 import (
+	"github.com/siyul-park/uniflow/pkg/packet"
 	"sync"
 
 	"github.com/siyul-park/uniflow/pkg/node"
@@ -208,9 +209,12 @@ func (n *Cluster) Close() error {
 func (n *Cluster) inbound(inPort *port.InPort, outPort *port.OutPort) port.Listener {
 	return port.ListenFunc(func(proc *process.Process) {
 		reader := inPort.Open(proc)
-		writer := outPort.Open(proc)
+		var writer *packet.Writer
 
 		for inPck := range reader.Read() {
+			if writer == nil {
+				writer = outPort.Open(proc)
+			}
 			if writer.Write(inPck) == 0 {
 				reader.Receive(inPck)
 			}
@@ -220,10 +224,13 @@ func (n *Cluster) inbound(inPort *port.InPort, outPort *port.OutPort) port.Liste
 
 func (n *Cluster) outbound(inPort *port.InPort, outPort *port.OutPort) port.Listener {
 	return port.ListenFunc(func(proc *process.Process) {
-		reader := inPort.Open(proc)
+		var reader *packet.Reader
 		writer := outPort.Open(proc)
 
 		for backPck := range writer.Receive() {
+			if reader == nil {
+				reader = inPort.Open(proc)
+			}
 			reader.Receive(backPck)
 		}
 	})