$instance :
$redis_con :
__construct()
getname( $userid)
savefd( $fd, $score, $kname = 'fd')
getfd( $kname = 'fd')
removefd( $fd, $kname = 'fd')
setkey( $data, $kname = 'fd')
getkey( $kname = 'fd')
delkey( $kname = 'fd')
getInstance()