func GroupExists(zkConn zkhelper.Conn, productName string, groupId int) (bool, error) {
zkPath := fmt.Sprintf("/zk/codis/db_%s/servers/group_%d", productName, groupId)
exists, _, err := zkConn.Exists(zkPath)
if err != nil {
return false, errors.Trace(err)
}
return exists, nil
}