diff --git a/conf.sample.yml b/conf.sample.yml
index e4f6348..8dee2ea 100644
--- a/conf.sample.yml
+++ b/conf.sample.yml
@@ -1,4 +1,4 @@
-Store: # specify which engine to store trans status
+# Store: # specify which engine to store trans status
 #   Driver: 'boltdb' # default store engine
 
 #   Driver: 'redis'
@@ -7,11 +7,11 @@ Store: # specify which engine to store trans status
 #   Password: ''
 #   Port: 6379
 
-  Driver: 'mysql'
-  Host: 'localhost'
-  User: 'root'
-  Password: ''
-  Port: 3306
+#   Driver: 'mysql'
+#   Host: 'localhost'
+#   User: 'root'
+#   Password: ''
+#   Port: 3306
 
 #   Driver: 'postgres'
 #   Host: 'localhost'
diff --git a/dtmsvr/config/config_test.go b/dtmsvr/config/config_test.go
index db62add..8088bef 100644
--- a/dtmsvr/config/config_test.go
+++ b/dtmsvr/config/config_test.go
@@ -18,12 +18,15 @@ func TestLoadFromEnv(t *testing.T) {
 }
 
 func TestCheckConfig(t *testing.T) {
+	MustLoadConfig("../../conf.sample.yml")
 	config := &Config
+	config.RetryInterval = 1
 	retryIntervalErr := checkConfig()
 	retryIntervalExpect := errors.New("RetryInterval should not be less than 10")
 	assert.Equal(t, retryIntervalErr, retryIntervalExpect)
 
 	config.RetryInterval = 10
+	config.TimeoutToFail = 5
 	timeoutToFailErr := checkConfig()
 	timeoutToFailExpect := errors.New("TimeoutToFail should not be less than RetryInterval")
 	assert.Equal(t, timeoutToFailErr, timeoutToFailExpect)
diff --git a/dtmsvr/storage/sql/sql.go b/dtmsvr/storage/sql/sql.go
index 45d03b3..7e4e74d 100644
--- a/dtmsvr/storage/sql/sql.go
+++ b/dtmsvr/storage/sql/sql.go
@@ -144,7 +144,7 @@ func (s *SqlStore) LockOneGlobalTrans(expireIn time.Duration) *storage.TransGlob
 	return global
 }
 
-func setDBConn(db *gorm.DB) {
+func SetDBConn(db *gorm.DB) {
 	sqldb, _ := db.DB()
 	sqldb.SetMaxOpenConns(int(conf.Store.MaxOpenConns))
 	sqldb.SetMaxIdleConns(int(conf.Store.MaxIdleConns))
@@ -152,7 +152,7 @@ func setDBConn(db *gorm.DB) {
 }
 
 func dbGet() *dtmutil.DB {
-	return dtmutil.DbGet(conf.Store.GetDBConf(), setDBConn)
+	return dtmutil.DbGet(conf.Store.GetDBConf(), SetDBConn)
 }
 
 func wrapError(err error) error {
diff --git a/test/common_test.go b/test/common_test.go
index 3b14e8d..21337fb 100644
--- a/test/common_test.go
+++ b/test/common_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/dtm-labs/dtm/dtmcli/dtmimp"
+	"github.com/dtm-labs/dtm/dtmsvr/storage/sql"
 	"github.com/dtm-labs/dtm/dtmutil"
 	"github.com/stretchr/testify/assert"
 )
@@ -16,7 +17,7 @@ func TestGeneralDB(t *testing.T) {
 }
 
 func testSql(t *testing.T) {
-	db := dtmutil.DbGet(conf.Store.GetDBConf())
+	db := dtmutil.DbGet(conf.Store.GetDBConf(), sql.SetDBConn)
 	err := func() (rerr error) {
 		defer dtmimp.P2E(&rerr)
 		db.Must().Exec("select a")