diff --git a/cluster/commands/mget.go b/cluster/commands/mget.go
new file mode 100644
index 0000000..1f99e38
--- /dev/null
+++ b/cluster/commands/mget.go
@@ -0,0 +1,2 @@
+package commands
+
diff --git a/cluster/commands/mset.go b/cluster/commands/mset.go
index 5884b55..e1fabc3 100644
--- a/cluster/commands/mset.go
+++ b/cluster/commands/mset.go
@@ -8,13 +8,28 @@ import (
 )
 
 func init() {
-	core.RegisterCmd("mset_", execMSet_)
+	core.RegisterCmd("mset_", execMSetInLocal)
+	core.RegisterCmd("mset", execMSet)
+
 }
 
 type CmdLine = [][]byte
 
-// execMSet_ executes msets in local node
-func execMSet_(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
+// node -> keys on the node
+type RouteMap map[string][]string
+
+func getRouteMap(cluster *core.Cluster, keys []string) RouteMap {
+	m := make(RouteMap)
+	for _, key := range keys {
+		slot := cluster.GetSlot(key)
+		node := cluster.PickNode(slot)
+		m[node] = append(m[node], key)
+	}
+	return m
+}
+
+// execMSetInLocal executes msets in local node
+func execMSetInLocal(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
 	if len(cmdLine) < 3 {
 		return protocol.MakeArgNumErrReply("mset")
 	}
@@ -22,15 +37,34 @@ func execMSet_(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis
 	return cluster.LocalExec(c, cmdLine)
 }
 
-func requestRollback(cluster *core.Cluster, c redis.Connection, txId string, routeMap map[string][]string) {
+func execMSet(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine) redis.Reply {
+	if len(cmdLine) < 3 || len(cmdLine)%2 != 1 {
+		return protocol.MakeArgNumErrReply("mset")
+	}
+	var keys []string
+	for i := 1; i < len(cmdLine); i += 2 {
+		keys = append(keys, string(cmdLine[i]))
+	}
+	routeMap := getRouteMap(cluster, keys)
+	if len(routeMap) == 1 {
+		// only one node, do it fast
+		for node := range routeMap {
+			cmdLine[0] = []byte("mset_")
+			return cluster.Relay(node, c, cmdLine)
+		}
+	}
+	return execMSetSlow(cluster, c, cmdLine, routeMap)
+}
+
+func requestRollback(cluster *core.Cluster, c redis.Connection, txId string, routeMap RouteMap) {
 	rollbackCmd := utils.ToCmdLine("rollback", txId)
-	for node  := range routeMap {
+	for node := range routeMap {
 		cluster.Relay(node, c, rollbackCmd)
 	}
 }
 
 // execMSetSlow execute mset through tcc
-func execMSetSlow(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine, routeMap map[string][]string) redis.Reply {
+func execMSetSlow(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine, routeMap RouteMap) redis.Reply {
 	txId := utils.RandString(6)
 
 	keyValues := make(map[string][]byte)
@@ -62,7 +96,7 @@ func execMSetSlow(cluster *core.Cluster, c redis.Connection, cmdLine CmdLine, ro
 
 	// send commit request
 	commiteCmd := utils.ToCmdLine("commit", txId)
-	for node  := range nodePrepareCmdMap {
+	for node := range nodePrepareCmdMap {
 		reply := cluster.Relay(node, c, commiteCmd)
 		if protocol.IsErrorReply(reply) {
 			requestRollback(cluster, c, txId, routeMap)
diff --git a/cluster/commands/mset_test.go b/cluster/commands/mset_test.go
new file mode 100644
index 0000000..50c2b16
--- /dev/null
+++ b/cluster/commands/mset_test.go
@@ -0,0 +1,20 @@
+package commands
+
+import (
+	"testing"
+
+	"github.com/hdt3213/godis/cluster/core"
+	"github.com/hdt3213/godis/lib/utils"
+	"github.com/hdt3213/godis/redis/connection"
+)
+
+func TestMset(t *testing.T) {
+	id1 := "1"
+	id2 := "2"
+	nodes := core.MakeTestCluster([]string{id1, id2})
+	node1 := nodes[id1]
+	c := connection.NewFakeConn()
+	// 1, 2 will be routed to node1 and node2, see MakeTestCluster
+	res := execMSet(node1, c, utils.ToCmdLine("mset", "1", "1", "2", "2"))
+	println(res)
+}
\ No newline at end of file
diff --git a/cluster/core/command.go b/cluster/core/command.go
index b78bde7..0a0d96d 100644
--- a/cluster/core/command.go
+++ b/cluster/core/command.go
@@ -62,7 +62,7 @@ func RegisterDefaultCmd(name string) {
 // relay command to responsible peer, and return its protocol to client
 func DefaultFunc(cluster *Cluster, c redis.Connection, args [][]byte) redis.Reply {
 	key := string(args[1])
-	slotId := GetSlot(key)
+	slotId := cluster.GetSlot(key)
 	peer := cluster.PickNode(slotId)
 	if peer == cluster.SelfID() {
 		// to self db
diff --git a/cluster/core/core.go b/cluster/core/core.go
index 84ce223..39cf3ca 100644
--- a/cluster/core/core.go
+++ b/cluster/core/core.go
@@ -22,6 +22,11 @@ type Cluster struct {
 	slotsManager    *slotsManager
 	rebalanceManger *rebalanceManager
 	transactions    *TransactionManager
+
+	// allow inject route implementation
+	getSlotImpl  func(key string) uint32
+	pickNodeImpl func(slotID uint32) string
+	id_          string // for tests only
 }
 
 type Config struct {
@@ -32,6 +37,9 @@ type Config struct {
 }
 
 func (c *Cluster) SelfID() string {
+	if c.raftNode == nil {
+		return c.id_
+	}
 	return c.raftNode.Cfg.ID()
 }
 
@@ -130,6 +138,12 @@ func NewCluster(cfg *Config) (*Cluster, error) {
 		slotsManager:    newSlotsManager(),
 		transactions:    newTransactionManager(),
 	}
+	cluster.pickNodeImpl = func(slotID uint32) string {
+		return defaultPickNodeImpl(cluster, slotID)
+	}
+	cluster.getSlotImpl = func(key string) uint32 {
+		return defaultGetSlotImpl(cluster, key)
+	}
 	cluster.injectInsertCallback()
 	cluster.injectDeleteCallback()
 	return cluster, nil
diff --git a/cluster/core/migration.go b/cluster/core/migration.go
index 27bb3c9..0ffec8c 100644
--- a/cluster/core/migration.go
+++ b/cluster/core/migration.go
@@ -46,7 +46,7 @@ func (sm *slotStatus) finishExportingWithinLock() {
 
 func (cluster *Cluster) injectInsertCallback() {
 	cb := func(dbIndex int, key string, entity *database.DataEntity) {
-		slotIndex := GetSlot(key)
+		slotIndex := cluster.GetSlot(key)
 		slotManager := cluster.slotsManager.getSlot(slotIndex)
 		slotManager.mu.Lock()
 		defer slotManager.mu.Unlock()
@@ -60,7 +60,7 @@ func (cluster *Cluster) injectInsertCallback() {
 
 func (cluster *Cluster) injectDeleteCallback() {
 	cb := func(dbIndex int, key string, entity *database.DataEntity) {
-		slotIndex := GetSlot(key)
+		slotIndex := cluster.GetSlot(key)
 		slotManager := cluster.slotsManager.getSlot(slotIndex)
 		slotManager.mu.Lock()
 		defer slotManager.mu.Unlock()
diff --git a/cluster/core/tcc.go b/cluster/core/tcc.go
index 6162de9..4bf901e 100644
--- a/cluster/core/tcc.go
+++ b/cluster/core/tcc.go
@@ -79,7 +79,7 @@ func execCommit(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.Rep
 	}
 	cluster.transactions.mu.Unlock()
 
-	resp := cluster.db.Exec(c, tx.realCmdLine)
+	resp := cluster.db.ExecWithLock(c, tx.realCmdLine)
 
 	// unlock regardless of result
 	cluster.db.RWUnLocks(0, tx.writeKeys, tx.readKeys)
@@ -88,7 +88,8 @@ func execCommit(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.Rep
 		// do not delete transaction, waiting rollback
 		return resp
 	}
-	// todo delete transaction after deadline
+
+	// todo: delete transaction after deadline
 	// cluster.transactions.mu.Lock()
 	// delete(cluster.transactions.txs, txId)
 	// cluster.transactions.mu.Unlock()
@@ -115,7 +116,7 @@ func execRollback(cluster *Cluster, c redis.Connection, cmdLine CmdLine) redis.R
 	cluster.db.RWLocks(0, tx.writeKeys, tx.readKeys)
 	for i := len(tx.undoLogs) - 1; i >= 0; i--  {
 		cmdline := tx.undoLogs[i]
-		cluster.db.Exec(c, cmdline)
+		cluster.db.ExecWithLock(c, cmdline)
 	}
 	cluster.db.RWUnLocks(0, tx.writeKeys, tx.readKeys)
 
diff --git a/cluster/core/tests.go b/cluster/core/tests.go
new file mode 100644
index 0000000..4847fd1
--- /dev/null
+++ b/cluster/core/tests.go
@@ -0,0 +1,43 @@
+package core
+
+import (
+	"strconv"
+
+	dbimpl "github.com/hdt3213/godis/database"
+)
+
+// MakeTestCluster creates a cluster for test, which communications are done through local function calls.
+func MakeTestCluster(ids []string) map[string]*Cluster {
+	nodes := make(map[string]*Cluster)
+	connections := NewInMemConnectionFactory()
+	connections.nodes = nodes
+	for _, id := range ids {
+		db := dbimpl.NewStandaloneServer()
+		cluster := &Cluster{
+			db:              db,
+			config:          &Config{},
+			connections:     connections,
+			rebalanceManger: newRebalanceManager(),
+			slotsManager:    newSlotsManager(),
+			transactions:    newTransactionManager(),
+			id_:             id,
+		}
+		cluster.pickNodeImpl = func(slotID uint32) string {
+			// skip raft for test
+			index := int(slotID) % len(ids)
+			return ids[index]
+		}
+		cluster.getSlotImpl = func(key string) uint32 {
+			// backdoor for test
+			i, err := strconv.Atoi(key)
+			if err == nil && i < SlotCount {
+				return uint32(i)
+			}
+			return defaultGetSlotImpl(cluster, key)
+		}
+		cluster.injectInsertCallback()
+		cluster.injectDeleteCallback()
+		nodes[id] = cluster
+	}
+	return nodes
+}
diff --git a/cluster/core/utils.go b/cluster/core/utils.go
index 01e55d6..b02eb30 100644
--- a/cluster/core/utils.go
+++ b/cluster/core/utils.go
@@ -52,15 +52,23 @@ func GetPartitionKey(key string) string {
 	return key[beg+1 : end]
 }
 
-func GetSlot(key string) uint32 {
+func defaultGetSlotImpl(cluster *Cluster, key string) uint32 {
 	partitionKey := GetPartitionKey(key)
 	return crc32.ChecksumIEEE([]byte(partitionKey)) % uint32(SlotCount)
 }
 
+func (cluster *Cluster) GetSlot(key string) uint32 {
+	return cluster.getSlotImpl(key)
+}
+
+func defaultPickNodeImpl(cluster *Cluster, slotID uint32) string {
+	return cluster.raftNode.FSM.PickNode(slotID)
+}
+
 // pickNode returns the node id hosting the given slot.
 // If the slot is migrating, return the node which is exporting the slot
 func (cluster *Cluster) PickNode(slotID uint32) string {
-	return cluster.raftNode.FSM.PickNode(slotID)
+	return cluster.pickNodeImpl(slotID)
 }
 
 // format: raft.committedindex