CaMELot: Catching and Mitigating Event-Loop Concurrency Issues

CaMELot：捕获并缓解事件循环并发问题

• 批准号: EP/V007165/1
• 负责人: Stefan Marr
• 金额: $ 26.73万
• 依托单位: University of Kent
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV007165%2F1
• 关键词: CaMELot; Catching; Mitigating; Event; Loop

Most modern computer applications depend in some way or another on computations that are performed by server applications on the internet. More and more of these server applications are now built as so-called microservices, which allow developers to gradually update or fix issues in unrelated parts of a larger application, and therefore, have become popular. Many of these microservices avoid certain types of concurrency issues by design. Unfortunately, they still suffer from other kinds of concurrency issues, for example when multiple online customers try to reserve the same seats at the same time.For software engineers, it is hard to test for all possible concurrent interactions. In practice, this means that only simple concurrency issues are reliably detected during testing. Complex issues can however easily slip through and make it into server applications and then handle client requests incorrectly. One example of such a concurrency issue appeared at Nasdaq when the Facebook stock was traded for the first time, resulting in the loss of millions of dollars.Our goal is to develop techniques that detect concurrency issues automatically at run time, to be able to circumvent them, and enable developers to fix them, using detailed information gathered by the detection techniques. Researchers have shown that one can detect and avoid issues, for instance by changing the order in which client requests are processed. In practice however, current techniques slow server applications down significantly, which make these techniques too costly to be used. Our aim is to dynamically balance the need for accurate information and minimize slow down. We conjecture that we can get most practical benefits while only rarely tracking precise details of how program code executes. In addition to automatically preventing concurrency issues to cause problems, we will also use the obtained information to provide feedback to developers so that they can fix the underlying issue in their software.Thus, overall the goal of this research project is to make server applications, and specifically microservices, more robust and resilient to software bugs that are hard to test for and therefore typically remain undiscovered until they cause major issues for customers or companies.Our work will result in the development of adaptive techniques that detect concurrency issues, and automatically tradeoff accuracy and run-time overhead, to be usable in practice. Furthermore, the detection techniques will be used to provide actionable input to the software developers, so that the concurrency issue can be fixed and therefore be prevented reliably in the future.To evaluate this work, we will collect various different types of concurrency issues and make them openly available. This collection will be based on issues from industrial systems and derived from theoretical scenarios for highly complex bugs. We include these theoretical scenarios, since such complex bugs are hard to diagnose and test for, they likely remain undiagnosed and undocumented in practice, but have the potential of causing major disruptions.Finally, we will build and evaluate our proposed techniques based on a system designed for concurrency research. The system uses the GraalVM technology of Oracle Labs, which allows us to prototype at the level of state-of-the-art systems, while keeping the development effort manageable for a small team.

大多数现代计算机应用程序都以某种方式依赖于互联网上服务器应用程序执行的计算。越来越多的服务器应用程序现在被构建为所谓的微服务，它允许开发人员逐步更新或修复大型应用程序中不相关部分的问题，因此变得流行起来。许多微服务在设计上避免了某些类型的并发性问题。不幸的是，它们仍然存在其他类型的并发性问题，例如，当多个在线客户试图同时预订相同的座位时。对于软件工程师来说，很难测试所有可能的并发交互。在实践中，这意味着只有简单的并发性问题才能在测试期间被可靠地检测到。然而，复杂的问题很容易渗透到服务器应用程序中，然后错误地处理客户机请求。这种并发性问题的一个例子出现在纳斯达克，当时Facebook股票首次交易，导致数百万美元的损失。我们的目标是开发在运行时自动检测并发性问题的技术，以便能够绕过并发性问题，并使开发人员能够使用检测技术收集的详细信息来修复并发性问题。研究人员已经证明，可以检测并避免问题，例如，通过改变处理客户端请求的顺序。然而，在实践中，目前的技术显著降低了服务器应用程序的速度，这使得这些技术的使用成本太高。我们的目标是动态平衡对准确信息的需求，并最大限度地降低速度。我们推测，在很少跟踪程序代码执行的精确细节的情况下，我们可以获得最实际的好处。除了自动防止并发问题导致问题之外，我们还将使用获得的信息向开发人员提供反馈，以便他们可以修复软件中的潜在问题。因此，本研究项目的总体目标是使服务器应用程序，特别是微服务，更健壮，更有弹性，以应对难以测试的软件错误，因此通常直到它们给客户或公司造成重大问题时才会被发现。我们的工作将导致自适应技术的开发，这些技术可以检测并发性问题，并自动权衡准确性和运行时开销，以便在实践中使用。此外，检测技术将用于向软件开发人员提供可操作的输入，以便可以修复并发性问题，从而在将来可靠地防止并发性问题。为了评估这项工作，我们将收集各种不同类型的并发性问题，并使它们公开可用。这个集合将基于来自工业系统的问题，并衍生于高度复杂的错误的理论场景。我们包含了这些理论场景，因为这些复杂的bug很难诊断和测试，它们在实践中可能仍然未被诊断和记录，但有可能导致重大中断。最后，我们将基于一个为并发研究而设计的系统来构建和评估我们提出的技术。该系统使用了Oracle实验室的GraalVM技术，它允许我们在最先进的系统水平上进行原型设计，同时保持小团队的开发工作可管理。

项目成果

Live Objects All The Way Down: Removing the Barriers between Applications and Virtual Machines

始终保持活动对象：消除应用程序和虚拟机之间的障碍

• DOI: 10.22152/programming-journal.org/2024/8/5
• 发表时间: 2023
• 期刊: The Art, Science, and Engineering of Programming
• 作者: Pimás J

Optimizing the Order of Bytecode Handlers in Interpreters using a Genetic Algorithm

使用遗传算法优化解释器中字节码处理程序的顺序

• DOI: 10.1145/3555776.3577712
• 发表时间: 2023
• 作者: Huang W

Dynamic Library Compartmentalization

动态库划分

• DOI: 10.1145/3618305.3623604
• 发表时间: 2023
• 作者: Larose O

Who You Gonna Call: Analyzing the Run-Time Call-Site Behavior of Ruby Applications

你要打电话给谁：分析 Ruby 应用程序的运行时调用站点行为

• DOI: 10.1145/3563834.3567538
• 发表时间: 2022
• 作者: Kaleba S

Profile Guided Offline Optimization of Hidden Class Graphs for JavaScript VMs in Embedded Systems

嵌入式系统中 JavaScript VM 隐藏类图的配置文件引导离线优化

• 发表时间: 2022
• 作者: Tomoharu Ugawa;Stefan Marr;Richard E. Jones
• 通讯作者: Richard E. Jones