I've accepted an answer, but sadly, I believe we're stuck with our original worst case scenario: CAPTCHA everyone on purchase attempts of the crap. Short explanation: caching / web farms make it impossible to track hits, and any workaround (sending a non-cached web-beacon, writing to a unified table, etc.) slows the site down worse than the bots would. There is likely some pricey hardware from Cisco or the like that can help at a high level, but it's hard to justify the cost if CAPTCHA-ing everyone is an alternative. I'll attempt a more full explanation later, as well as cleaning this up for future searchers (though others are welcome to try, as it's community wiki).

情况

这是关于woot.com上的垃圾销售。我是Woot Workshop的总统,Woot Workshop是Woot的子公司,负责设计,撰写产品描述,播客,博客文章,并主持论坛。我使用CSS/HTML,对其他技术几乎不熟悉。我与开发人员密切合作,在这里讨论了所有的答案(以及我们的许多其他想法)。

可用性是我工作的重要组成部分,而让网站变得令人兴奋和有趣则是剩下的大部分工作。这就是下面三个目标的来源。验证码损害了可用性,机器人从我们的垃圾销售中偷走了乐趣和兴奋。

机器人一秒钟就会在我们的首页上猛击数十次屏幕抓取(和/或扫描我们的RSS),以寻找随机垃圾销售。他们一看到这个,就会触发程序的第二阶段登录,点击“我要一个”,填好表格,然后买下这些垃圾。

评价

lc:在stackoverflow和其他使用此方法的站点上,他们几乎总是处理已验证(登录)的用户,因为正在尝试的任务需要这样。

在Woot上,匿名(未登录)用户可以查看我们的主页。换句话说,撞击机器人可以不经过身份验证(除了IP地址之外基本上无法跟踪)。

所以我们又回到了扫描IP, a)在这个云网络和垃圾邮件僵尸的时代是相当无用的,b)考虑到来自一个IP地址的业务数量,捕获了太多无辜的人(更不用说非静态IP isp的问题和试图跟踪它的潜在性能影响)。

还有,让别人给我们打电话是最糟糕的情况。我们能让他们给你打电话吗?

布拉德克:内德·巴切德的方法看起来很酷,但它们是专门设计来击败为网络站点构建的机器人的。我们的问题是机器人是专门用来破坏我们网站的。其中一些方法可能只在很短的时间内有效,直到脚本编写人员将他们的机器人进化为忽略蜜罐,从屏幕上抓取附近的标签名称而不是表单id,并使用支持javascript的浏览器控件。

 

lc再次说道:“当然,除非炒作是你们营销计划的一部分。”是的,绝对是。当物品出现时的惊喜,以及当你设法得到一件物品时的兴奋,可能比你实际得到的垃圾一样重要,甚至更重要。任何消除先到/先得的东西都不利于“赢”的快感。

 

novatrust:就我个人而言,欢迎我们新的机器人霸主。我们实际上提供RSSfeeds,允许第三方应用程序扫描我们的网站的产品信息,但不是在主站HTML之前。如果我的理解正确的话,你的解决方案通过完全牺牲目标1来帮助目标2(性能问题),并放弃机器人将购买大部分垃圾的事实。我给你的回答投了赞成票,因为你最后一段的悲观情绪对我来说是准确的。这里似乎没有什么灵丹妙药。

其余的响应通常依赖于IP跟踪,这似乎是无用的(僵尸网络/僵尸/云网络)和有害的(捕获许多来自相同IP目的地的无辜的人)。

还有其他方法/想法吗?我的开发人员一直在说“让我们只做验证码”,但我希望有更少的侵入性方法,让所有真正想要我们的垃圾的人。

最初的问题

假设你卖的东西很便宜,但有很高的感知价值,而你的数量非常有限。没有人确切地知道你什么时候会卖这个东西。超过一百万人经常来看你卖什么。

你最终会发现脚本和机器人试图通过编程方式[a]找出你何时出售该道具,[b]确保他们是第一批购买该道具的人。这很糟糕,有两个原因:

你的网站被非人类攻击,拖慢了所有人的速度。 编剧最终“赢得”了产品,让常客感到被骗了。

一个看似显而易见的解决方案是为用户在下单前设置一些障碍,但这至少有三个问题:

The user experience sucks for humans, as they have to decipher CAPTCHA, pick out the cat, or solve a math problem. If the perceived benefit is high enough, and the crowd large enough, some group will find their way around any tweak, leading to an arms race. (This is especially true the simpler the tweak is; hidden 'comments' form, re-arranging the form elements, mis-labeling them, hidden 'gotcha' text all will work once and then need to be changed to fight targeting this specific form.) Even if the scripters can't 'solve' your tweak it doesn't prevent them from slamming your front page, and then sounding an alarm for the scripter to fill out the order, manually. Given they get the advantage from solving [a], they will likely still win [b] since they'll be the first humans reaching the order page. Additionally, 1. still happens, causing server errors and a decreased performance for everyone.

另一种解决方案是经常监视ip攻击,阻止它们进入防火墙,或以其他方式阻止它们排序。这个可以解2。和阻止[b],但扫描ip对性能的影响是巨大的,可能会导致更多像1这样的问题。比编剧自己造成的还要严重。此外,云网络和垃圾邮件僵尸的可能性使得IP检查相当无用。

第三个想法,强迫订单表单加载一段时间(比如半秒),可能会减慢快速订单的进度,但同样,脚本编写人员仍然是第一个进入的人,在任何速度下都不会对实际用户造成损害。

目标

将道具卖给非脚本人。 保持网站运行的速度不被机器人减慢。 不要让“正常”用户完成任何任务来证明他们是人类。


当前回答

我们目前正在使用F5的最新一代BigIP负载均衡器来实现这一点。BigIP具有先进的流量管理功能,可以根据频率和使用模式识别抓取者和机器人,甚至可以从单个IP后面的一组源中识别。然后,它可以限制这些内容,为它们提供替代内容,或者简单地用标题或cookie标记它们,以便您可以在应用程序代码中识别它们。

其他回答

Trying to target the BOTs themselves will never solve the problem - whoever is writing them will figure out a new way around whatever you've put in place. However forcing the user to think before buying would be a much more effective solution. The best way of doing this that I can think of is run a Dutch auction. Start the price high (2x what you buy it for in the shop) and decrease it over time. The first person to hit buy gets it. I don't think any bot is intelligent enough to workout what the best price is for the item.

Honestly, I think your best solution is to make items during a Woot-Off only be visible to logged in users, and limit each logged-in user to one home page refresh every 500ms or so. (Or possibly make only a picture of the item be visible to unauthenticated users during a Woot-Off, and make sure you don't always use the same picture for Random Crap.) I think Woot users would be willing to accept this if you sell it as a measure to help them get their Bowls of Creaminess, and you can also point out that it'll help them check out quicker. Anything else--even using captchas--is subject to your typical arms race.

这里最重要的事情是改变系统,从你的服务器上移除负载,防止机器人在不让奶瓶商知道你在和他们玩游戏的情况下赢得这袋垃圾,否则他们会修改他们的策略。我认为如果你们不进行一些处理,就没有办法做到这一点。

So you record hits on your home page. Whenever someone hits the page that connection is compared to its last hit, and if it was too quick then it is sent a version of the page without the offer. This can be done by some sort of load balancing mechanism that sends bots (the hits that are too fast) to a server that simply serves cached versions of your home page; real people get sent to the good server. This takes the load off the main server and makes the bots think that they are still being served the pages correctly.

如果这个提议能以某种方式被拒绝就更好了。然后你仍然可以在假服务器上提供报价,但当机器人填写表格时,说“对不起,你不够快”:)然后他们肯定会认为他们还在游戏中。

Go after the money stream. It is much easier than tracking the IP side. Make bots pay too much a few times (announcement with white text on white background and all variants of it) kills their business case quickly. You should prepare this carefully, and make good use of the strong points of bots: their speed. Did you try a few thousand fake announcements a few seconds apart? If they are hitting ten times/second you can go even faster. You want to keep this up as long as they keep buying, so think carefully about the moment of the day/week you want to start this. Ideally, they will stop paying, so you can hand over your case to a bank. Make sure your site is fully generated, and each page access returns different page content (html, javascript and css). Parsing is more difficult than generating, and it is easy to build-in more variation than bot developers can handle. Keep on changing the content and how you generate it. You need to know how fast bots can adapt to changes you make, and preferably the timezone they are in. Is it one botnet or more, are they in the same timezone, a different one, or is it a worldwide developer network? You want your counterattack to be timed right. Current state of the art bots have humans enter captcha's (offered against porn/games). Make it unattractive to react very fast. Use hashes and honeypots, as Ned Batchelder explains.

(编辑) 你不能防御僵尸网络的说法是不对的。特别是我的第二个建议提供了充分的防御自动买家。不过,这需要你彻底重新思考你所使用的技术。您可能希望使用Seaside或直接在c中进行一些实验。

这个问题的解决方案可能是在登录和购买操作中附加一些客户端处理。处理量可以忽略不计,因此个人不会受到影响,但多次尝试执行任务的机器人将受到额外工作负载的阻碍。

处理过程可以是一个用javascript解决的简单方程,除非你不想在你的网站上需要javascript。