DCS: Mobile Applications in Computational Grids

背景网格计算为开发新型应用程序创造了机会。这两类应用程序是在计算资源之间移动以利用计算资源的应用程序，以及在服务器之间迁移以实现对硬件故障的弹性的应用程序。这两个都是计算网格中移动应用程序的实例。为了实现完全的移动性，应用程序必须能够将它们的状态从一个平台移动到另一个平台，这个平台可能具有不同的处理器架构（处理器无关）和不同数量的处理器（平台无关）。将现有的静态应用程序转换为移动应用程序的问题可以在语言、编译器、中间件或操作系统级别上解决。理想的解决方案应该(i)对应用程序编写人员透明，（ii）允许在异构平台之间移动，（iii）使应用程序在硬件故障方面健壮，以及（iv）产生最小的性能损失。PI将结合使用编译器技术和运行时系统来解决这个问题。该解决方案基于应用程序级检查点，这是一种对应用程序进行检测的方法，这样它就可以保存和恢复自己的状态，而无需操作系统或体系结构的任何帮助。为了达到机制透明的目的，将采用编译器技术对代码进行自动检测。MPI程序的应用程序级检查点需要一个分布式协议来确保进程在采取检查点时得到协调。该协议由一个瘦运行时层执行。PI已经实现了这样一个系统，用于接受不可移植的检查点（也就是说，检查点只能在与创建它的平台完全相同的平台上启动）。对该系统的研究表明，开销很小。我们的计划是扩展这个系统，使它所使用的检查点既独立于体系结构又独立于平台。在C和c++环境中做到这一点是具有挑战性的。最终系统的实验评估将与匹兹堡超级计算中心（PSC）联合进行。移动应用程序的广泛部署有望释放新兴电网系统的潜力。所提出的系统将使许多现有的并行代码能够快速安全地转换到汽车应用中。为了证明我们的方法和系统的有效性，PI计划将一些静态应用程序转换为移动应用程序。这些应用程序本身就很有用。因此，提出的系统将使计算科学家不必成为网格专家就可以开始使用网格。项目产生的工具将向公众开放。许多研究生都参与了这个项目——Greg Bronevetsky， Dan Marques， Milind Kulkarni和Rohit Fernandes。Bronevetsky是NSF的研究生。因此，该项目将为美国培养训练有素的科学家和工程师做出贡献。PI有向代表性不足的群体伸出援手的传统。在美国国家科学基金会基础设施研究基金的支持下，PI接待了许多来自马萨诸塞州史密斯学院的女学生，她们在夏天做研究项目。国际扶轮计划的资助刚刚结束。如果这项建议得到资助，PI可以继续这种推广。

BackgroundGrid computing has created the opportunity for developing new classes of applications. Two such classesare applications that move between computing resources to exploit computational resources, and applicationsthat migrate between servers to achieve resilience to hardware faults. Both of these are instances ofmobile applications in computational grids. To achieve full mobility, applications must be able to movetheir state from one platform to another one that may have a different processor architecture (processor independence)and a different number of processors (platform-independence).The problem of converting existing static applications into mobile applications can be addressed atthe language, compiler, middleware or operating systems level. An ideal solution would (i) be transparentto the application writer, (ii) permit mobility among heterogenous platforms, (iii) make applications robust with respect to hardware failures, and (iv) incur minimal performance penalty.The PI will address this problem using a combination of compiler technology and runtime systems.The solution is based on application-level checkpointing, an approach in which an application is instrumented so that it can save and restore its own state without any assistance from the operating system orarchitecture. To achieve the goal of mechanism transparency, compiler technology will be used to automatically instrument codes in this way. Application-level checkpointing of MPI programs requires a distributed protocol to ensure that processes are coordinated when they take their checkpoints. This protocol is executedby a thin runtime layer.The PI has implemented such a system for taking non-portable checkpoints (that is, checkpoints that canonly be started on a platform identical in every way to the platform on which it was created). Studies of thissystem show that the overheads are small. The plan is to extend this system so that the checkpointsit takes are both architecture-independent and platform-independent. Doing this in the context of C andC++ is challenging. Experimental evaluation of the resulting system will be carried out jointly with the Pittsburgh Supercomputing Center (PSC).Intellectual MeritThe wide deployment of mobile applications promises to unlock the potential of emerging grid systems.The proposed system will enable many existing parallel codes to be quickly and safely transformed intomobile applications. To demonstrate the effectiveness of our approach and systems, The PI plans to convert anumber of static applications into mobile applications. These applications will be useful in their own right.Therefore, the proposed system will enable computational scientists to start using the grid without havingto become grid experts.Broader Impact The tools produced by the project will be made publicly available. A number of graduate students areinvolved in the project - Greg Bronevetsky, Dan Marques, Milind Kulkarni, and Rohit Fernandes. Bronevetsky is an NSF graduate fellow. The project will therefore contribute to the pool of trained scientists and engineers in the US.The PI has a tradition of outreach to under-represented groups. With support from an NSF ResearchInfrastructure grant, The PI has hosted a number of female students from Smith College in Massachusetts,who spent the summer doing research projects. Funding from the RI project has just ended. Ifthis proposal is funded, the PI can continue this outreach.