diff --git a/conf/xenon-sample.conf.json b/conf/xenon-sample.conf.json
index 15d6648..84fc4c3 100644
--- a/conf/xenon-sample.conf.json
+++ b/conf/xenon-sample.conf.json
@@ -17,7 +17,7 @@
 		"version":"mysql80",
 		"passwd":"",
 		"host":"localhost",
-		"port":${YOUR-MYSQL-PORT},
+		"port":"${YOUR-MYSQL-PORT}",
 		"basedir":"${YOUR-MYSQL-BIN-DIR}",
 		"defaults-file":"${YOUR-MYSQL-CNF-PATH}"
 	},
@@ -35,7 +35,8 @@
 		"ssh-passwd":"${YOUR-SSH-PWD}",
 		"basedir":"${YOUR-MYSQL-BIN-DIR}",
 		"backupdir":"${YOUR-BACKUP-DIR}",
-		"xtrabackup-bindir":"${YOUR-XTRABACKUP-BIN-DIR}"
+		"xtrabackup-bindir":"${YOUR-XTRABACKUP-BIN-DIR}",
+		"max-allowed-local-trx-count": "${YOUR-MAX-ALLOWED-LOCAL-TRX-COUNT}"
 	},
 
 	"rpc":
diff --git a/docs/config/192.168.0.11_xenon.md b/docs/config/192.168.0.11_xenon.md
index 7b576ac..5b92c80 100644
--- a/docs/config/192.168.0.11_xenon.md
+++ b/docs/config/192.168.0.11_xenon.md
@@ -34,7 +34,7 @@
 		"ssh-user":"ubuntu",
 		"ssh-passwd":"",
 		"basedir":"/usr",
-		"backup-dir":"/data/mysql",
+		"backupdir":"/data/mysql",
 		"xtrabackup-bindir":"/opt/xtrabackup/bin"
 	},
 
diff --git a/docs/config/192.168.0.2_xenon.md b/docs/config/192.168.0.2_xenon.md
index 90d8efe..127e6d1 100644
--- a/docs/config/192.168.0.2_xenon.md
+++ b/docs/config/192.168.0.2_xenon.md
@@ -34,7 +34,7 @@
 		"ssh-user":"ubuntu",
 		"ssh-passwd":"",
 		"basedir":"/usr",
-		"backup-dir":"/data/mysql",
+		"backupdir":"/data/mysql",
 		"xtrabackup-bindir":"/opt/xtrabackup/bin"
 	},
 
diff --git a/docs/config/192.168.0.3_xenon.md b/docs/config/192.168.0.3_xenon.md
index cdb3d8e..aa6d5b1 100644
--- a/docs/config/192.168.0.3_xenon.md
+++ b/docs/config/192.168.0.3_xenon.md
@@ -34,7 +34,7 @@
 		"ssh-user":"ubuntu",
 		"ssh-passwd":"",
 		"basedir":"/usr",
-		"backup-dir":"/data/mysql",
+		"backupdir":"/data/mysql",
 		"xtrabackup-bindir":"/opt/xtrabackup/bin"
 	},
 
diff --git a/docs/config/xenon-simple.conf.json b/docs/config/xenon-simple.conf.json
index ba54d92..da477e7 100644
--- a/docs/config/xenon-simple.conf.json
+++ b/docs/config/xenon-simple.conf.json
@@ -38,11 +38,12 @@
 		"ssh-user":"ubuntu",
 		"ssh-passwd":"ubuntu",
 		"ssh-port":22,
-		"backup-dir":"/home/ubuntu/data3306",
+		"backupdir":"/home/ubuntu/data3306",
 		"xtrabackup-bindir":"/home/ubuntu/xtrabackup_20161216",
 		"backup-iops-limits":100000,
 		"backup-use-memory": "2GB",
-		"backup-parallel": 2
+		"backup-parallel": 2,
+		"max-allowed-local-trx-count": 0
 	},
 
 	"rpc":
diff --git a/docs/how_to_build_and_run_xenon.md b/docs/how_to_build_and_run_xenon.md
index 7bb9d25..f035fe2 100644
--- a/docs/how_to_build_and_run_xenon.md
+++ b/docs/how_to_build_and_run_xenon.md
@@ -145,7 +145,7 @@ $ sudo vi /etc/xenon/xenon.json
         "ssh-user":"${YOUR-SSH-USER}",
         "ssh-passwd":"${YOUR-SSH-PWD}",
         "basedir":"${YOUR-MYSQL-BIN-DIR}",
-        "backup-dir":"${YOUR-BACKUP-DIR}",
+        "backupdir":"${YOUR-BACKUP-DIR}",
         "xtrabackup-bindir":"${YOUR-XTRABACKUP-BIN-DIR}"
     },
 
diff --git a/src/cli/callx/callx.go b/src/cli/callx/callx.go
index 94bfde5..78085f6 100644
--- a/src/cli/callx/callx.go
+++ b/src/cli/callx/callx.go
@@ -753,6 +753,23 @@ func GetGTIDRPC(node string) (*model.MysqlStatusRPCResponse, error) {
 	return rsp, err
 }
 
+func GetGTIDSubtractRPC(node string, subsetGTID string, setGTID string) (*model.MysqlGTIDSubtractRPCResponse, error) {
+	cli, cleanup, err := GetClient(node)
+	if err != nil {
+		return nil, err
+	}
+	defer cleanup()
+
+	method := model.RPCMysqlGTIDSubtract
+	req := model.NewMysqlGTIDSubtractRPCRequest()
+	req.SubsetGTID = subsetGTID
+	req.SetGTID = setGTID
+	rsp := model.NewMysqlGTIDSubtractRPCResponse(model.OK)
+	err = cli.Call(method, req, rsp)
+
+	return rsp, err
+}
+
 // GetMysqlUserRPC get mysql user
 func GetMysqlUserRPC(node string) (*model.MysqlUserRPCResponse, error) {
 	cli, cleanup, err := GetClient(node)
diff --git a/src/cli/cmd/mysql.go b/src/cli/cmd/mysql.go
index 1e972da..f74ac02 100644
--- a/src/cli/cmd/mysql.go
+++ b/src/cli/cmd/mysql.go
@@ -14,6 +14,7 @@ import (
 	"fmt"
 	"model"
 	"path"
+	"strconv"
 	"strings"
 	"time"
 	"xbase/common"
@@ -150,19 +151,67 @@ func mysqlShutDownCommandFn(cmd *cobra.Command, args []string) {
 // rebuild me
 var (
 	fromStr string
+	force   bool
 )
 
 func NewMysqlRebuildMeCommand() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "rebuildme [--from=endpoint]",
-		Short: "rebuild a slave --from=endpoint",
+		Use:   "rebuildme [--from=endpoint][--force]",
+		Short: "rebuild a slave --from=endpoint --force",
 		Run:   mysqlRebuildMeCommandFn,
 	}
 	cmd.Flags().StringVar(&fromStr, "from", "", "--from=endpoint")
+	cmd.Flags().BoolVar(&force, "force", false, "--force")
 
 	return cmd
 }
 
+func getLocalTrxCount(self string, bestone string) (int, error) {
+	count := 0
+
+	rsp1, err := callx.GetGTIDRPC(bestone)
+	if err != nil {
+		return -1, fmt.Errorf("get.gtid.from.bestone[%v].failed[%v]", bestone, err)
+	} else if rsp1.GTID.Executed_GTID_Set == "" {
+		return -1, fmt.Errorf("the.Executed_GTID_Set.of.bestone[%v].is.null", bestone)
+	}
+	fromGTID := rsp1.GTID
+
+	rsp1, err = callx.GetGTIDRPC(self)
+	if err != nil {
+		return -1, fmt.Errorf("get.gtid.from.myself[%v].failed[%v]", self, err)
+	} else if rsp1.GTID.Executed_GTID_Set == "" {
+		return -1, fmt.Errorf("the.Executed_GTID_Set.of.myself[%v].is.null", self)
+	}
+	localGTID := rsp1.GTID
+
+	rsp2, err := callx.GetGTIDSubtractRPC(self, localGTID.Executed_GTID_Set, fromGTID.Executed_GTID_Set)
+	if err != nil {
+		return -1, fmt.Errorf("get.gtid.subtract.from.self[%v].failed[%v]", self, err)
+	}
+	subtract := rsp2.Subtract
+
+	// compute the number of local transactions
+	gtidSet := strings.Split(subtract, "\n")
+	for _, gtid := range gtidSet {
+		gtid = strings.TrimSpace(gtid)
+		gtid = strings.TrimSuffix(gtid, ",")
+		diffs := strings.Split(gtid, ":")[1:]
+		for _, diff := range diffs {
+			values := strings.Split(diff, "-")
+			if len(values) == 1 {
+				count += 1
+			} else {
+				s, _ := strconv.Atoi(values[0])
+				e, _ := strconv.Atoi(values[1])
+				count += e - s + 1
+			}
+		}
+	}
+
+	return count, nil
+}
+
 func mysqlRebuildMeCommandFn(cmd *cobra.Command, args []string) {
 	if len(args) != 0 {
 		ErrorOK(fmt.Errorf("too.many.args"))
@@ -183,6 +232,7 @@ func mysqlRebuildMeCommandFn(cmd *cobra.Command, args []string) {
 	datadir := conf.Backup.BackupDir
 	binlogDir := ""
 	binlogPrefix := ""
+	maxAllowedLocalTrxCount := conf.Backup.MaxAllowedLocalTrxCount
 
 	// 1. first to check I am leader or not
 	{
@@ -190,11 +240,11 @@ func mysqlRebuildMeCommandFn(cmd *cobra.Command, args []string) {
 		leader, err := callx.GetClusterLeader(self)
 		ErrorOK(err)
 		if leader == self {
-			log.Panic("[%v].I.am.leader.you.cant.rebuildme.sir", self)
+			log.Panic("I[%v].am.leader.you.cant.rebuildme.sir", self)
 		}
 	}
 
-	// 2. find the best to backup
+	// 2. find the best to backup and check gtid
 	{
 		if fromStr != "" {
 			bestone = fromStr
@@ -203,6 +253,22 @@ func mysqlRebuildMeCommandFn(cmd *cobra.Command, args []string) {
 			ErrorOK(err)
 		}
 		log.Warning("S2-->prepare.rebuild.from[%v]....", bestone)
+
+		// check if there are more than 2 local transactions on the local node than bestone
+		if force {
+			log.Warning("S2-->the.[--force].is.specified.skip.check.gtid")
+		} else {
+			working, err := callx.MysqlIsWorkingRPC(self)
+			ErrorOK(err)
+			if working == false {
+				log.Panic("local.mysql.is.not.working.you.cant.rebuildme.sir")
+			}
+			localTrxCount, err := getLocalTrxCount(self, bestone)
+			ErrorOK(err)
+			if localTrxCount > maxAllowedLocalTrxCount {
+				log.Panic("I[%v].have.[%v].local.transactions.more.than.maxAllowedLocalTrxCount[%v].compared.to.from[%v].you.cant.rebuildme.sir", self, localTrxCount, maxAllowedLocalTrxCount, bestone)
+			}
+		}
 	}
 
 	// 3. check bestone is not in BACKUPING
diff --git a/src/config/config.go b/src/config/config.go
index ec0f372..a818cb0 100644
--- a/src/config/config.go
+++ b/src/config/config.go
@@ -200,16 +200,17 @@ func (c *ReplicationConfig) UnmarshalJSON(b []byte) error {
 
 type BackupConfig struct {
 	// MUST: set in init
-	SSHHost               string `json:"ssh-host"`
-	SSHUser               string `json:"ssh-user"`
-	SSHPasswd             string `json:"ssh-passwd"`
-	SSHPort               int    `json:"ssh-port"`
-	BackupDir             string `json:"backupdir"`
-	XtrabackupBinDir      string `json:"xtrabackup-bindir"`
-	BackupIOPSLimits      int    `json:"backup-iops-limits"`
-	UseMemory             string `json:"backup-use-memory"`
-	Parallel              int    `json:"backup-parallel"`
-	MysqldMonitorInterval int    `json:"mysqld-monitor-interval"`
+	SSHHost                 string `json:"ssh-host"`
+	SSHUser                 string `json:"ssh-user"`
+	SSHPasswd               string `json:"ssh-passwd"`
+	SSHPort                 int    `json:"ssh-port"`
+	BackupDir               string `json:"backupdir"`
+	XtrabackupBinDir        string `json:"xtrabackup-bindir"`
+	BackupIOPSLimits        int    `json:"backup-iops-limits"`
+	UseMemory               string `json:"backup-use-memory"`
+	Parallel                int    `json:"backup-parallel"`
+	MysqldMonitorInterval   int    `json:"mysqld-monitor-interval"`
+	MaxAllowedLocalTrxCount int    `json:"max-allowed-local-trx-count"`
 
 	// mysql admin
 	Admin string
@@ -232,19 +233,20 @@ type BackupConfig struct {
 
 func DefaultBackupConfig() *BackupConfig {
 	return &BackupConfig{
-		SSHPort:               22,
-		BackupDir:             "/u01/backup",
-		XtrabackupBinDir:      ".",
-		BackupIOPSLimits:      100000,
-		UseMemory:             "2GB",
-		Parallel:              2,
-		MysqldMonitorInterval: 1000 * 1,
-		Admin:                 "root",
-		Passwd:                "",
-		Host:                  "localhost",
-		Port:                  3306,
-		Basedir:               "/u01/mysql_20160606/",
-		DefaultsFile:          "/etc/my3306.cnf",
+		SSHPort:                 22,
+		BackupDir:               "/u01/backup",
+		XtrabackupBinDir:        ".",
+		BackupIOPSLimits:        100000,
+		UseMemory:               "2GB",
+		Parallel:                2,
+		MysqldMonitorInterval:   1000 * 1,
+		MaxAllowedLocalTrxCount: 0,
+		Admin:                   "root",
+		Passwd:                  "",
+		Host:                    "localhost",
+		Port:                    3306,
+		Basedir:                 "/u01/mysql_20160606/",
+		DefaultsFile:            "/etc/my3306.cnf",
 	}
 }
 
diff --git a/src/model/mysql.go b/src/model/mysql.go
index 859c476..953cb6b 100644
--- a/src/model/mysql.go
+++ b/src/model/mysql.go
@@ -10,6 +10,7 @@ package model
 
 const (
 	RPCMysqlStatus                   = "MysqlRPC.Status"
+	RPCMysqlGTIDSubtract             = "MysqlRPC.GTIDSubtract"
 	RPCMysqlSetGlobalSysVar          = "MysqlRPC.SetGlobalSysVar"
 	RPCMysqlCreateUserWithPrivileges = "UserRPC.CreateUserWithPrivileges"
 	RPCMysqlCreateNormalUser         = "UserRPC.CreateNormalUser"
@@ -153,6 +154,34 @@ func NewMysqlStatusRPCResponse(code string) *MysqlStatusRPCResponse {
 	return &MysqlStatusRPCResponse{RetCode: code}
 }
 
+type MysqlGTIDSubtractRPCRequest struct {
+	// The IP of this request
+	From string
+
+	// The first parameter of the function GTID_SUBTRACT
+	SubsetGTID string
+
+	// The second parameter of the function GTID_SUBTRACT
+	SetGTID string
+}
+
+type MysqlGTIDSubtractRPCResponse struct {
+	// The GTID Subtract of this request
+	Subtract string
+
+	// Return code to rpc client:
+	// OK or other errors
+	RetCode string
+}
+
+func NewMysqlGTIDSubtractRPCRequest() *MysqlGTIDSubtractRPCRequest {
+	return &MysqlGTIDSubtractRPCRequest{}
+}
+
+func NewMysqlGTIDSubtractRPCResponse(code string) *MysqlGTIDSubtractRPCResponse {
+	return &MysqlGTIDSubtractRPCResponse{RetCode: code}
+}
+
 // user
 type MysqlUserRPCRequest struct {
 	// The IP of this request
diff --git a/src/mysql/api.go b/src/mysql/api.go
index 3a5281b..3aa4add 100644
--- a/src/mysql/api.go
+++ b/src/mysql/api.go
@@ -165,7 +165,7 @@ func (m *Mysql) CheckGTID(followerGTID *model.GTID, candidateGTID *model.GTID) b
 
 	// gtid_sub is not none, means the follower gtid is bigger than candidate gtid
 	// if viewdiff<=0 and gtid_sub is not null it must be localcommitted
-	gtid_sub, err := m.GetGtidSubtract(fGTID, cGTID)
+	gtid_sub, err := m.GetGTIDSubtract(fGTID, cGTID)
 	if err != nil {
 		log.Error("mysql.CheckGTID.error[%v]", err)
 		return false
@@ -176,12 +176,12 @@ func (m *Mysql) CheckGTID(followerGTID *model.GTID, candidateGTID *model.GTID) b
 	return false
 }
 
-func (m *Mysql) GetGtidSubtract(subsetGTID string, setGTID string) (string, error) {
+func (m *Mysql) GetGTIDSubtract(subsetGTID string, setGTID string) (string, error) {
 	db, err := m.getDB()
 	if err != nil {
 		return "", err
 	}
-	return m.mysqlHandler.GetGtidSubtract(db, subsetGTID, setGTID)
+	return m.mysqlHandler.GetGTIDSubtract(db, subsetGTID, setGTID)
 }
 
 // StartSlaveIOThread used to start the slave io thread.
diff --git a/src/mysql/mock.go b/src/mysql/mock.go
index 44919d1..c437362 100644
--- a/src/mysql/mock.go
+++ b/src/mysql/mock.go
@@ -172,8 +172,8 @@ func DefaultCheckGTID(followerGTID *model.GTID, leaderGTID *model.GTID) bool {
 	return false
 }
 
-// GetGtidSubtract mock.
-func (mogtid *MockGTID) GetGtidSubtract(db *sql.DB, slaveGTID string, masterGTID string) (string, error) {
+// GetGTIDSubtract mock.
+func (mogtid *MockGTID) GetGTIDSubtract(db *sql.DB, slaveGTID string, masterGTID string) (string, error) {
 	return mogtid.GetGtidSubtractFn(db, slaveGTID, masterGTID)
 }
 
diff --git a/src/mysql/mysql_handler.go b/src/mysql/mysql_handler.go
index 7e23c3d..d52f137 100644
--- a/src/mysql/mysql_handler.go
+++ b/src/mysql/mysql_handler.go
@@ -54,7 +54,7 @@ type MysqlHandler interface {
 	GetUUID(db *sql.DB) (string, error)
 
 	// get gtid subtract with slavegtid and master gtid
-	GetGtidSubtract(*sql.DB, string, string) (string, error)
+	GetGTIDSubtract(*sql.DB, string, string) (string, error)
 
 	// set global variables
 	SetGlobalSysVar(db *sql.DB, varsql string) error
diff --git a/src/mysql/mysqlbase.go b/src/mysql/mysqlbase.go
index cd88702..a243488 100644
--- a/src/mysql/mysqlbase.go
+++ b/src/mysql/mysqlbase.go
@@ -215,8 +215,8 @@ func (my *MysqlBase) WaitUntilAfterGTID(db *sql.DB, targetGTID string) error {
 	return Execute(db, query)
 }
 
-// GetGtidSubtract used to do "SELECT GTID_SUBTRACT('subsetGTID','setGTID') as gtid_sub" command
-func (my *MysqlBase) GetGtidSubtract(db *sql.DB, subsetGTID string, setGTID string) (string, error) {
+// GetGTIDSubtract used to do "SELECT GTID_SUBTRACT('subsetGTID','setGTID') as gtid_sub" command
+func (my *MysqlBase) GetGTIDSubtract(db *sql.DB, subsetGTID string, setGTID string) (string, error) {
 	query := fmt.Sprintf("SELECT GTID_SUBTRACT('%s','%s') as gtid_sub", subsetGTID, setGTID)
 	rows, err := QueryWithTimeout(db, my.queryTimeout, query)
 	if err != nil {
diff --git a/src/mysql/rpc_mysql.go b/src/mysql/rpc_mysql.go
index 590b386..c2be817 100644
--- a/src/mysql/rpc_mysql.go
+++ b/src/mysql/rpc_mysql.go
@@ -106,3 +106,15 @@ func (m *MysqlRPC) Status(req *model.MysqlStatusRPCRequest, rsp *model.MysqlStat
 	rsp.Stats = m.mysql.getStats()
 	return nil
 }
+
+// GTIDSubstract returns the mysql GTID subtract info.
+func (m *MysqlRPC) GTIDSubtract(req *model.MysqlGTIDSubtractRPCRequest, rsp *model.MysqlGTIDSubtractRPCResponse) error {
+	var err error
+
+	rsp.RetCode = model.OK
+	if rsp.Subtract, err = m.mysql.GetGTIDSubtract(req.SubsetGTID, req.SetGTID); err != nil {
+		rsp.RetCode = err.Error()
+		return nil
+	}
+	return nil
+}
diff --git a/src/raft/leader.go b/src/raft/leader.go
index 77d9d7e..360db16 100644
--- a/src/raft/leader.go
+++ b/src/raft/leader.go
@@ -444,7 +444,7 @@ func (r *Leader) purgeBinlogStart() {
 			leader.purgeBinlog()
 		}
 	}(r)
-	r.INFO("purge.bing.start[%vms]...", r.conf.PurgeBinlogInterval)
+	r.INFO("purge.binlog.start[%vms]...", r.conf.PurgeBinlogInterval)
 }
 
 func (r *Leader) purgeBinlogStop() {
diff --git a/src/raft/raft.go b/src/raft/raft.go
index d0fbf1f..7820e74 100644
--- a/src/raft/raft.go
+++ b/src/raft/raft.go
@@ -212,7 +212,7 @@ func (r *Raft) freePeers() {
 	}
 }
 
-// send command to state machine(F/C/L/I/S) loop with maxSendTime tiemout
+// send command to state machine(F/C/L/I/S) loop with maxSendTime timeout
 // (F/C/L/I/S)-loop should handle it and return
 func (r *Raft) send(t int, request interface{}, maxSendTime int) (interface{}, error) {
 	if !r.running() {