diff --git a/cmd/launch/main.go b/cmd/launch/main.go
new file mode 100644
index 00000000..5e936a04
--- /dev/null
+++ b/cmd/launch/main.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+var numNodes = flag.Int("numNodes", 1, "The number of nodes for distributed training")
+var nodeRank = flag.Int("nodeRank", 0, "The rank of the node")
+var nprocPerNode = flag.Int("nprocPerNode", 1, "The number of processes on each node")
+var masterAddr = flag.String("masterAddr", "127.0.0.1", "The address of master node(rank 0)")
+var masterPort = flag.Int("masterPort", 11111, "The port of master node")
+var sharedFile = flag.String("sharedFile", "", "The shared file which could be access by all processes")
+var trainingCmd = flag.String("trainingCmd", "", "The training command")
+
+func main() {
+	flag.Parse()
+
+	commands := []string{}
+	size := (*numNodes) * (*nprocPerNode)
+	for i := 0; i < *nprocPerNode; i++ {
+		rank := (*nprocPerNode)*(*nodeRank) + i
+		cmd := fmt.Sprintf("%s -rank=%d -size=%d", *trainingCmd, rank, size)
+		if *masterAddr != "" {
+			cmd = fmt.Sprintf("%s -masterAddr=%s -masterPort=%d", cmd, *masterAddr, *masterPort)
+		} else if *sharedFile != "" {
+			cmd = fmt.Sprintf("%s -sharedFile=%s", cmd, *sharedFile)
+		} else {
+			panic("Must set value for masterAddr or sharedFile")
+		}
+		commands = append(commands, cmd)
+	}
+
+	for _, cmd := range commands {
+		args := strings.Fields(cmd)
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Start()
+	}
+}
diff --git a/example/allreduce/main.go b/example/allreduce/main.go
new file mode 100644
index 00000000..7f129ab9
--- /dev/null
+++ b/example/allreduce/main.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"flag"
+
+	torch "github.com/wangkuiyi/gotorch"
+	F "github.com/wangkuiyi/gotorch/nn/functional"
+	"github.com/wangkuiyi/gotorch/vision/models"
+)
+
+var masterAddr = flag.String("masterAddr", "127.0.0.1", "The address of master node(rank 0)")
+var masterPort = flag.Int("masterPort", 11111, "The port of master node")
+var rank = flag.Int("rank", 0, "The rank of the current process")
+var size = flag.Int("size", 1, "The size of the processes")
+
+func getGrads(params []torch.Tensor) (grads []torch.Tensor) {
+	for _, p := range params {
+		grads = append(grads, p.Grad())
+	}
+	return
+}
+
+func main() {
+	flag.Parse()
+
+	ts := torch.NewTCPStore(*masterAddr, int64(*masterPort), int64(*size), *rank == 0)
+	defer ts.Close()
+	pg := torch.NewProcessGroupGloo(ts, int64(*rank), int64(*size))
+	defer pg.Close()
+
+	net := models.MLP()
+	opt := torch.SGD(0.01, 0.5, 0, 0, false)
+	params := net.Parameters()
+	opt.AddParameters(params)
+
+	for _, p := range params {
+		pg.Broadcast([]torch.Tensor{p})
+	}
+
+	for i := 0; i < 10; i++ {
+		data := torch.Rand([]int64{16, 28, 28}, false)
+		label := torch.Ones([]int64{16}, false).CastTo(torch.Long)
+
+		opt.ZeroGrad()
+		pred := net.Forward(data)
+		loss := F.NllLoss(pred, label, torch.Tensor{}, -100, "mean")
+		loss.Backward()
+
+		grads := getGrads(params)
+		pg.AllReduceCoalesced(grads)
+
+		opt.Step()
+	}
+}
diff --git a/nn/module.go b/nn/module.go
index 5f21caf3..fd9e0031 100644
--- a/nn/module.go
+++ b/nn/module.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"reflect"
+	"sort"
 
 	torch "github.com/wangkuiyi/gotorch"
 )
@@ -163,12 +164,21 @@ func (m *Module) NamedBuffers() map[string]torch.Tensor {
 	return r
 }
 
+func sortKeys(ts map[string]torch.Tensor) (keys []string) {
+	for k := range ts {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return
+}
+
 // Parameters returns trainable parameters (recursively)
 func (m *Module) Parameters() []torch.Tensor {
 	result := make([]torch.Tensor, 0)
 	n := m.NamedParameters()
-	for _, v := range n {
-		result = append(result, v)
+	keys := sortKeys(n)
+	for _, k := range keys {
+		result = append(result, n[k])
 	}
 	return result
 }
@@ -177,8 +187,9 @@ func (m *Module) Parameters() []torch.Tensor {
 func (m *Module) Buffers() []torch.Tensor {
 	result := make([]torch.Tensor, 0)
 	n := m.NamedBuffers()
-	for _, v := range n {
-		result = append(result, v)
+	keys := sortKeys(n)
+	for _, k := range keys {
+		result = append(result, n[k])
 	}
 	return result
 }