mysql报MySQL server has gone away

当主服务器重启后，从服务器是否需要重启？查看后台进程报MySQL server has gone away错误

错误日志如下：
误信息：执行操作失败：2006:MySQL server has gone away
错误地址：http://u.china.com/group/pindex.php?_a=upinfo&gid=257
错误类型：iException
错误跟踪：
[11-05-05 18:02:05] /www/u.china.com/core/class/db/driver/DbMysql.class.php (201) throw_exception(执行操作失败：2006:MySQL server has gone away, sys)[11-05-05 18:02:05] /www/u.china.com/core/class/db/db.class.php (206) DbMysql->_execute(update photo_info
                                set description='20110505_180208_539594.jpg',
                                name='20110505_180208_539594.jpg'
                                where id = 29271)[11-05-05 18:02:05] /www/u.china.com/htdocs/group/pindex.php (1075) Db->execute(update photo_info
                                set description='20110505_180208_539594.jpg',
                                name='20110505_180208_539594.jpg'
                                where id = 29271)

查看错误日志时报：101014 14:07:09 [Warning] Statement may not be safe to log in statement format. Statement: update `repaste_info` set `reading_num`=
`reading_num` + 1 where `id` = '131' limit 1