标签 ‘ Framework

Dissecting the Disruptor: How do I read from the ring buffer?

原文地址:http://mechanitis.blogspot.com/2011/06/dissecting-disruptor-how-do-i-read-from.html(因为有墙转载到墙内)

作者:Trisha

The next in the series of understanding the Disruptor pattern developed at LMAX.

After the last post we all understand ring buffers and how awesome they are.  Unfortunately for you, I have not said anything about how to actually populate them or read from them when you’re using the Disruptor.

ConsumerBarriers and Consumers
I’m going to approach this slightly backwards, because it’s probably easier to understand in the long run.  Assuming that some magic has populated it: how do you read something from the ring buffer?

(OK, I’m starting to regret using Paint/Gimp.  Although it’s an excellent excuse to purchase a graphics tablet if I do continue down this road.  Also UML gurus are probably cursing my name right now.)

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Dissecting the Disruptor: Writing to the ring buffer

原文地址:http://mechanitis.blogspot.com/2011/07/dissecting-disruptor-writing-to-ring.html(因被墙移到墙内)  作者:Trisha

This is the missing piece in the end-to-end view of the Disruptor.  Brace yourselves, it’s quite long.  But I decided to keep it in a single blog so you could have the context in one place.

The important areas are: not wrapping the ring; informing the consumers; batching for producers; and how multiple producers work. 阅读全文

Disruptor 2.0 – All Change Please

原文地址:http://mechanitis.blogspot.com/2011/08/disruptor-20-all-change-please.html  (因被墙移到墙内)  作者:Trisha

Martin recently announced version 2.0 of the Disruptor – basically there have been so many changes since we first open-sourced it that it’s time to mark that officially.  His post goes over all the changes, the aim of this article is to attempt to translate my previous blog posts into new-world-speak, since it’s going to take a long time to re-write each of them all over again. Now I see the disadvantage of hand-drawing everything.

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Dissecting the Disruptor: What’s so special about a ring buffer?

原文地址:http://mechanitis.blogspot.com/2011/06/dissecting-disruptor-whats-so-special.html(因被墙移到墙内) 作者:Trisha

Recently we open sourced the LMAX Disruptor, the key to what makes our exchange so fast.  Why did we open source it?  Well, we’ve realised that conventional wisdom around high performance programming is… a bit wrong. We’ve come up with a better, faster way to share data between threads, and it would be selfish not to share it with the world.  Plus it makes us look dead clever.

On the site you can download a technical article explaining what the Disruptor is and why it’s so clever and fast.  I even get a writing credit on it, which is gratifying when all I really did is insert commas and re-phrase sentences I didn’t understand.

However I find the whole thing a bit much to digest all at once, so I’m going to explain it in smaller pieces, as suits my NADD audience.

First up – the ring buffer.  Initially I was under the impression the Disruptor was just the ring buffer.  But I’ve come to realise that while this data structure is at the heart of the pattern, the clever bit about the Disruptor is controlling access to it.
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剖析Disruptor:为什么会这么快?(一)锁的缺点

原文:http://ifeve.com/disruptor-locks-are-bad/

作者:Trisha’s  译者:张文灼,潘曦  整理和校对:方腾飞,丁一

Martin Fowler写了一篇非常好的文章,里面不仅提到了Disruptor,而且还解释了Disruptor 如何应用在LMAX的架构里。里面有提及了一些目前没有涉及的概念,但最经常问到的问题是 “Disruptor究竟是什么?"。

目前我正准备在回答这个问题,但首先回答"为什么它会这么快?"

这些问题持续出现,但是我不能没有说它是干什么的就说它为什么会这么快,不能没有说它为什么这样做就说它是什么东西。

所以我陷入了一个僵局,一个如何写博客的僵局。

要打破这个僵局,我准备以最简单方式回答第一个问题,如果幸运的话,在以后博文里,如果需要解释的话我会重新提回:Disruptor提供了一种线程之间信息交换的方式。

作为一个开发者,因为"线程"一词的出现,我的警钟已经敲响,它意味着并发,而并发是困难的。

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LMAX架构

原文地址:http://martinfowler.com/articles/lmax.html 作者:Martin Fowler

译文地址:http://www.jdon.com/42452 译者:banq

LMAX是一种新型零售金融交易平台,它能够以很低的延迟(latency)产生大量交易(吞吐量). 这个系统是建立在JVM平台上,核心是一个业务逻辑处理器,它能够在一个线程里每秒处理6百万订单. 业务逻辑处理器完全是运行在内存中(in-memory),使用事件源驱动方式(event sourcing). 业务逻辑处理器的核心是Disruptors,这是一个并发组件,能够在无锁的情况下实现网络的Queue并发操作。他们的研究表明,现在的所谓高性能研究方向似乎和现代CPU设计是相左的。

目录

  1. 整体架构
  2. 业务逻辑处理
  3. Disruptors的输入和输出
  4. 队列和机制偏爱的缺乏
  5. 你需要使用这个架构吗

 

过去几年我们不断提供这样声音:免费午餐已经结束。我们不再能期望在单个CPU上获得更快的性能,因此我们需要写使用多核处理的并发软件,不幸的是, 编写并发软件是很难的,锁和信号量是很难理解的和难以测试,这意味着我们要花更多时间在计算机上,而不是我们的领域问题,各种并发模型,如Actors 和软事务STM(Software Transactional Memory), 目的是更加容易使用,但是按下葫芦飘起瓢,还是带来了bugs和复杂性.

我很惊讶听到去年3月QCon上一个演讲, LMAX是一种新的零售的金融交易平台。它的业务创新 – 允许任何人在一系列的金融衍生产品交易。这就需要非常低的延迟,非常快速的处理,因为市场变化很快,这个零售平台因为有很多人同时操作自然具备了复杂性,用户越多,交易量越大,不断快速增长。

鉴于多核心思想的转变,这种苛刻的性能自然会提出一个明确的并行编程模型 ,但是他们却提出用一个线程处理6百万订单,而且是每秒,在通用的硬件上。

通过低延迟处理大量交易,取得低延迟和高吞吐量,而且没有并发代码的复杂性,他们是怎么做到呢?现在LMAX已经产品化一段时间了,现在应该可以揭开其神秘而迷人的面纱了。

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Dissecting the Disruptor: Demystifying Memory Barriers

原文地址:http://mechanitis.blogspot.com/2011/08/dissecting-disruptor-why-its-so-fast.html (因有墙,移到墙内)

My recent slow-down in posting is because I’ve been trying to write a post explaining memory barriersand their applicability in the Disruptor. The problem is, no matter how much I read and no matter how many times I ask the ever-patient Martin and Mike questions trying to clarify some point, I just don’t intuitively grasp the subject. I guess I don’t have the deep background knowledge required to fully understand.

So, rather than make an idiot of myself trying to explain something I don’t really get, I’m going to try and cover, at an abstract / massive-simplification level, what I do understand in the area.  Martin has written a post going into memory barriers in some detail, so hopefully I can get away with skimming the subject.

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Dissecting the Disruptor: Why it’s so fast (part two) – Magic cache line padding

原文地址:http://mechanitis.blogspot.com/2011/07/dissecting-disruptor-why-its-so-fast_22.html(因有墙移到墙内)

We mention the phrase Mechanical Sympathy quite a lot, in fact it’s even Martin’s blog title.  It’s about understanding how the underlying hardware operates and programming in a way that works with that, not against it.

We get a number of comments and questions about the mysterious cache line padding in theRingBuffer, and I referred to it in the last post.  Since this lends itself to pretty pictures, it’s the next thing I thought I would tackle.
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Dissecting the Disruptor: Why it’s so fast (part one) – Locks Are Bad

原文地址:http://mechanitis.blogspot.com/2011/07/dissecting-disruptor-why-its-so-fast.html(因前方有墙,所以我移到墙内)

Martin Fowler has written a really good article describing not only the Disruptor, but also how it fits into the architecture at LMAX.  This gives some of the context that has been missing so far, but the most frequently asked question is still “What is the Disruptor?”.

I’m working up to answering that.  I’m currently on question number two: “Why is it so fast?”.

 

These questions do go hand in hand, however, because I can’t talk about why it’s fast without saying what it does, and I can’t talk about what it is without saying why it is that way.

So I’m trapped in a circular dependency.  A circular dependency of blogging.

To break the dependency, I’m going to answer question one with the simplest answer, and with any luck I’ll come back to it in a later post if it still needs explanation: the Disruptor is a way to pass information between threads.
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