DCS: Mobile Applications in Computational Grids

背景网格计算为开发新的应用程序类别创造了机会。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恢复能力的应用程序。这两个都是计算网格中移动应用的实例。为了实现完全的移动性，应用程序必须能够将其状态从一个平台移动到另一个平台，该平台可能具有不同的处理器架构（处理器无关性）和不同数量的处理器（平台无关性）。将现有的静态应用程序转换为移动的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。一个理想的解决方案是（i）对应用程序编写者的兼容性，（ii）允许异构平台之间的移动性，（iii）使应用程序在硬件故障方面具有鲁棒性，（iv）产生最小的性能损失。PI将使用编译器技术和运行时系统的组合来解决这个问题。该解决方案基于应用程序级检查点，一种方法，在这种方法中，应用程序被检测，以便它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标，编译器技术将被用来自动仪器代码在这种方式。MPI程序的应用程序级检查点需要一个分布式协议，以确保进程在获取检查点时得到协调。PI已经实现了这样一个系统，用于获取不可移植的检查点（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，系统的管理费用很小。我们的计划是扩展这个系统，使它所采用的检查点既独立于架构，也独立于平台。在C和C++的环境中做这件事是很有挑战性的。 将与匹兹堡超级计算中心（PSC）共同对由此产生的系统进行实验评估。智力优点移动的应用程序的广泛部署有望释放新兴网格系统的潜力。为了证明我们的方法和系统的有效性，PI计划将大量的静态应用程序转换为移动的应用程序。这些应用程序本身将是有用的。因此，拟议中的系统将使计算科学家开始使用网格，而不必成为网格专家。更广泛的影响该项目产生的工具将公开提供。一些研究生参与了这个项目--格雷格·布罗涅韦茨基、丹·马克斯、米林德·库尔卡尼和罗希特·费尔南德斯。Bronevetsky是NSF的研究生研究员。因此，该项目将有助于美国训练有素的科学家和工程师的人才库。PI有一个传统的外展代表性不足的群体。在NSF研究基础设施拨款的支持下，PI接待了来自马萨诸塞州史密斯学院的一些女学生，她们花了一个夏天做研究项目。国际康复会项目的供资刚刚结束。如果该提案得到资助，PI可以继续开展该推广活动。

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.