ITR/SY: SmartApps: An Application Centric Approach to Scientific Computing

最先进的运行时系统与不同的、动态的分布式应用程序不太匹配，因为它们被设计为为各种应用程序提供支持，而不是针对个别特定需求进行太多定制。从应用程序到运行时系统的信息流很少或根本没有，从而使运行时系统能够根据应用程序完全定制其服务。因此，业绩令人失望。为了解决这个问题，该项目将采用以应用程序为中心的计算或智能应用程序(SMARTAPPS)。SMARTAPPS的压倒一切的哲学是“衡量、比较和适应(如果有益)”。也就是说，应用程序将持续监视其性能和可用资源，以确定应用程序是否可以通过重构提高其性能，以及提高多少。然后，如果潜在的性能收益超过了预计的管理成本，应用程序将相应地重新构建自身和底层系统。此过程持续进行，以适应应用程序的动态需求和系统资源的可用性。该自适应可以在各种级别发生，包括选择适用于当前问题的算法方法、运行时并行化和其他相关的编译器优化、调整可重新配置的OS服务(例如，调度策略)、以及系统配置(例如，选择使用哪些计算资源)。SMARTAPPS框架提供性能监控和建模组件，以及执行实际重构的机制，以集成这些级别的适应。本项目将在整个开发过程中在几个重要的计算科学应用程序和代表性平台上测试SMARTAPPS。从计算物理学的角度，它将研究模拟亚原子粒子传输的离散坐标代码。从计算生物学的角度，它将研究分子动力学代码和模拟蛋白质折叠和配体结合(也称为药物对接)的代码。SMARTAPPS将在当前的分布式、不同的平台上开发和运行，包括ASCI机器、大型NUMA机器、工作站网络，并最终在网格上运行。

State-of-the-art run-time systems are a poor match to diverse, dynamic distributed applications because they are designed to provide support to a wide variety of applications, without much customization to individual specific requirements. Little or no information flows from the application to the run-time system to allow the latter to fully tailor its services to the application. As a result, the performance is disappointing. To address this problem, this project will pursue application-centric computing, or Smart Applications (SMARTAPPS). The overriding philosophy of SMARTAPPS is "measure, compare, and adapt if beneficial." That is, the application will continually monitor its performance and the available resources to determine if, and by how much, the application could improve its performance by restructuring. Then, if the potential performance benefit outweighs the projected overhead costs, the application will restructure itself and the underlying system accordingly. This process occurs continuously to adapt to the dynamic needs of the application and the availability of system resources. The adaptation can occur at various levels including selection of an algorithmic approach suitable for the current problem, run-time parallelization and other related compiler optimizations, tuning reconfigurable OS services (e.g. scheduling policy), and system configuration (e.g., selecting which computational resources to use). The SMARTAPPS framework provides performance monitoring and modeling components, as well as mechanisms for performing the actual restructuring, to integrate these levels of adaptation.This project will test SMARTAPPS on several important computational science applications and representative platforms throughout the development process. From computational physics, it will study discrete-ordinates codes that simulate subatomic particle transport. From computational biology, it will study a molecular dynamics code and a code that simulates protein folding and ligand binding (also known as drug docking). SMARTAPPS will be developed and run on current distributed, heterogeneous platforms, including the ASCI machines, large NUMA machines, networks of workstations, and, ultimately, the Grid.