Life is not a State-Machine

||评论 (

上周我在ACM给了一个主题演讲分布式计算原理关于技术转让主题的会议(PODC)。我选择的话题是最近的一些其他研究展示的介绍,他们认为分布式计算研究界未能达到标记;很多好的想法,影响很小。

I subscribe to a longer term point of view when it comes to the transformation of technology into successful products.理查德加布里埃尔createda modelthat lays out the time it takes and means by which innovations become successful consumable products[1]。它肯定适合许多Xerox Parc创新,电子表格甚至网络的市场成功。To illustrate, hyperlinks and markup languages were developed in the mid sixties, the tcp/ip based networks came to life in the seventies, and it wasn’t until the mid nineties before the combination of these three turned into the basis for a mass consumer product. Gabriel’s presentation on “软件验收模型:赢家如何获胜” has more examples and a better connection to the “Crossing the Chasm[2]“思维风格。

我相信这适用于大部分深度,基本,分布式的系统材料。例如,Felipe Cabrera曾表示,当Vista在明年船舶在编程语言中的支持下船舶时,它将在IBM的Quicksilver项目中开发的概念之后超过20年。必威体育精装版app官网

但事情正在加速。Amazon.com和其他地方使用高质量,大型分布式系统的优势,并要求使用最近的研究技术利用这种大规模的规模。我们看到超出了既定技术,如边缘缓存,懒惰处理,融合,融合等等技术的提升。

采用更多最近用于产品的研究技术并不是在公园散步。必须非常确定工程师克服早期采用的许多障碍。

Unrealistic assumptions

Research is focused on the details of the technology itself, and not very focused on the application context of the technology. Often, to be able to make progress in research, you need to restrict the environment it can be applied to. For example, many academics will confess to have made the assumption that failures of component are not correlated. This absolutely unrealistic assumption will come back to haunt you in real life, where failures frequently are correlated, as they are often triggered by external or environmental events.

选择研究技术时,往往是一个重大练习,了解研究人员所做的具体假设。然后,更加困难的练习是弄清楚你是否可以与这些假设一起生活,无论假设是否相关,或者是否可能妨碍采用技术。在后一种情况下,是否有一些我们可以做些什么来将研究带来更现实的标准。

Uncertainty

许多不可逾越的假设处理reasoning away uncertainty. By turning life into a state machine in which no surprises can be found, one has the perfect world in which everything is clean and organized. There is a limit to how much you can trick life into being predictable and how much control you think you will have to keep life in-check. At small scale you may succeed, but when your systems grow in size and complexity you will lose control. As such, building scalable systems is all about letting go of control. (Turing’s Type I organizations)

In Control Theory, for a long time, researchers were convinced that practitioners did not want to use their research because there was too much complex math in it. It turned out however that the research was largely irrelevant in practice because it didn’t model a realistic world. The moment researchers started to produce work that explicitly took uncertainty into account, their work was rapidly adopted by engineers and architects. Ironically the math has only grown more complex…

In distributed systems we see a similar pattern arising; research which realistically models uncertainty is more readily useful for adoption. Randomization and self-organizing systems are crucial techniques for scaling systems in the real world.

A perfect world

The last topic I want to mention is the use of academic publications as a source of technology selection. Academics often battle out subtle competing views in their research papers. But if there are at least 10 competing approaches to implementing consensus in distributed systems, an engineer needs to make a judgment call on which approach would be best to solve his problems. If the academics can’t even make their mind up on what appears to be the right way, how can their customers be expected to do this for them.

论文通常以极其积极的方式编写:“这是一次再次,自切片面包以来的生活中最好的改善”。几乎没有自我批评。肯定没有关于没有工作的事情的细节,为什么他们没有工作。让我们甚至没有开始谈论在系统研究论文中使用统计数据。我们真的只关心平均线吗?当然,假设实验首先是现实的。

您需要重新执行现实环境中最有前途的研究成果,以帮助您的选择。没有其他办法了。这意味着只有工程师真的需要这些结果,只会考虑这些研究成果,因为它会非常耗时。

奥卡姆剃刀

这是我们实际使用的场合Occam’s Razor在原来的意义上;如果两种方法产生相同的结果,请选择具有最少用假设的。我们经常看到,这种选择标准将导致您获得最大可能采用的技术。

entia non sunt multiplicanda praeter necessitatem

[1] Gabriel, Richard, "通过创新重新考虑的资金" inPatterns of Software: Tales from the Software Community,牛津大学出版社,美国;重印版(1998年5月1日)(download book pdf)。

[2]Moore, Geoffrey A., “越过鸿沟:营销和销售高科技产品到主流客户” HarperBusiness; Rev edition (July 1999)

Comments