Collaborative Research: SI2-SSI: Expanding Volunteer Computing

志愿计算（VC）使用捐赠的计算时间消费设备，如家用电脑和智能手机来进行科学计算。事实证明，与组织计算中心和商业云等传统方法相比，风险投资可以以更低的成本提供更强的计算能力。BOINC是VC最常用的软件框架。基本上，计算时间的捐赠者只需要在他们的电脑或智能手机上加载BOINC，然后在BOINC网站上注册捐赠。VC提供“高吞吐量计算”：处理大量独立的作业，其性能目标基于作业的完成率，而不是单个作业的完成时间。这种类型的计算（都被称为高吞吐量计算）在大多数科学领域都有很大的需求。到目前为止，风险投资的采用一直受到其结构的限制。例如，VC项目（如Einstein@home和Rosetta@home）是由个人研究小组运营的，志愿者必须在许多这样的项目中进行浏览和选择。因此，风险投资项目相对较少，志愿者大多是精通技术的计算机爱好者。该项目旨在通过两项互补的开发工作来解决这些问题：首先，它将为两个主要的高性能计算提供商增加基于boinc的VC管道：(a)德克萨斯高级计算中心（一个超级计算机中心）和(b) nanoHUB（一个提供计算能力的纳米科学门户网站）。此外，将开发一个统一的VC控制界面，暂定名为Science United，捐助者可以在那里注册。该项目将使使用这些设施的数千名科学家受益，并将创造技术，使其他HPC提供商更容易添加自己的VC后端。此外，科学联合将为BOINC志愿者提供一个更简单的界面，他们将在那里注册以支持科学领域，而不是具体的项目。科学联合还将在项目之间分配计算能力。因此，新项目将不再需要自己做营销和宣传来招募志愿者。最后，创建一个单一的风险投资“品牌”（即科学联合）将允许风险投资向公众进行连贯的营销。通过建立一个巨大的低成本计算能力池，将使成千上万的科学家受益，并提高公众对科学的认识和兴趣，该项目计划将风险投资建立为美国科学网络基础设施的核心和长期组成部分。将VC添加到现有的HPC设施中涉及到几个技术问题，这些问题将被解决如下：(1)打包科学应用程序（通常在Linux集群节点上运行）以运行在家用计算机上（主要是Windows，一些Mac和Linux）；该团队正在开发一种使用VirtualBox和Docker的方法，其中应用程序及其环境（Linux发行版，库，可执行文件）被表示为包含Docker映像的一组层，然后在志愿者设备上的Linux虚拟机上作为容器运行。这有许多优点：它将包装应用的工作减少到接近零；它最小化了网络流量，因为一个给定的Docker层只被下载到一个主机上一次；(2)文件管理：输入和输出文件必须在现有的私人服务器和面向公众的服务器之间移动，这些服务器可以被外部互联网访问。为此，将开发一个基于Web rpc的文件管理系统。该系统将使用基于内容的命名，以便给定的文件只传输和存储一次。它还维护作业/文件关联，以便在不再需要文件时自动从公共服务器删除这些文件。(3)提交和监控作业：BOINC提供了一个web界面，可以高效地提交和监控大批量的作业。它们最初是作为将HTCondor作业迁移到BOINC的系统的一部分而开发的。该项目正在对其进行扩展，以支持TACC和nanoHUB的附加需求。请注意，这些新功能并非特定于TACC或nanoHUB：它们提供了将基于boinc的VC轻松添加到任何现有HTC设施所需的粘合剂。该团队还在用几种语言（Python、c++、PHP）开发RPC绑定。该项目的另一个组成部分是Science United，它是一个数据库驱动的网站，并为BOINC客户提供相关的web服务。科学联合将使用BOINC的“客户经理”机制控制志愿者主机（即告诉他们为哪些项目工作），其中每个主机上的BOINC客户端定期与科学联合联系并被告知运行哪些项目。分发作业和文件的将是项目服务器，而不是科学联合。科学联合将为科学领域（物理、生物医学、环境等）和地点（国家、机构）定义一组“关键词”。项目将标有适当的关键字。志愿者将有一个yes/no/maybe接口，用于指定他们想要运行的作业类型。因此，科学联合将提供一种机制，在这种机制中，总计算能力的一小部分可以在给定时期内分配给一个项目。由于总容量随时间变化缓慢，因此这允许几乎确定的保证分配。科学联合将体现一个调度系统，试图强制分配，尊重志愿者的偏好，并最大限度地提高吞吐量。最后，科学联合将对计算机进行详细核算。志愿者主持人将告诉Science United他们为每个项目完成了多少工作（通过CPU时间和FLOPs、GPU时间和FLOPs以及作业数来衡量）。科学联合将维护志愿者和项目的这些数据的历史记录，以及更细粒度的当前总数（例如，每个主机/项目组合）。最后，科学联合将提供网络界面，让志愿者看到他们的捐款状态和历史，并允许管理员添加项目、控制分配和查看会计数据。

Volunteer computing (VC) uses donated computing time consumer devices such as home computers and smartphones to do scientific computing. It has been shown that VC can provide greater computing power, at lower cost, than conventional approaches such as organizational computing centers and commercial clouds. BOINC is the most common software framework for VC. Essentially, donors of computing time simply have to load BOINC on their computer or smartphone, and then register to donate at the BOINC web site. VC provides "high throughput computing": handling lots of independent jobs, with performance goals based on the rate of job completion rather than completion time for individual jobs. This type of computing (all known as high-throughput computing) is in great demand in most areas of science. Until now, the adoption of VC has been limited by its structure. For example, VC projects (such as Einstein@home and Rosetta@home) are operated by individual research groups, and volunteers must browse and choose from among many such projects. As a result, there are relatively few VC projects, and volunteers are mostly tech-savvy computer enthusiasts. This project aims to solve these problems using two complementary development efforts: First, it will add BOINC-based VC conduits to two major high-performance computing providers: (a) the Texas Advanced Computing Center, a supercomputer center, and (b) nanoHUB, a web portal for nano science that provides computing capabilities.Also, a unified control interface to VC will be developed, tentatively called Science United, where donors can register. The project will benefit thousands of scientists who use these facilities, and it will create technology that makes it easy for other HPC providers to add their own VC back ends. Also, Science United will provide a simpler interface to BOINC volunteers where they will register to support scientific areas, rather than specific projects. Science United will also serve as an allocator of computing power among projects. Thus, new projects will no longer have to do their own marketing and publicity to recruit volunteers. Finally, the creation of a single VC "brand" (i.e Science United) will allow coherent marketing of VC to the public. By creating a huge pool of low-cost computing power that will benefit thousands of scientists, and increasing public awareness of and interest in science, the project plans to establish VC as a central and long-term part of the U.S. scientific cyber infrastructure.Adding VC to an existing HPC facility involves several technical issues, which will be addressed as follows: (1) Packaging science applications (which typically run on Linux cluster nodes) to run on home computers (mostly Windows, some Mac and Linux): the team is developing an approach using VirtualBox and Docker, in which the application and its environment (Linux distribution, libraries, executables) are represented as a set of layers comprising a Docker image, which is then run as a container within a Linux virtual machine on the volunteer device. This has numerous advantages: it reduces the work of packaging applications to near zero; it minimizes network traffic because a given Docker layer is downloaded to a host only once; and it provides a strong security sandbox so that volunteer computers are protected from buggy or malicious applications, (2) File management: Input and output files must be moved between existing private servers and public-facing servers that are accessible to the outside Internet. A file management system will be developed, based on Web RPCs, for this purpose. This system will use content-based naming so that a given file is transferred and stored only once. It also maintains job/file associations so that files can be automatically deleted from the public server when they are no longer needed. (3) Submitting and monitoring jobs: BOINC provides a web interface for efficiently submitting and monitoring large batches of jobs. These were originally developed as part of a system to migrate HTCondor jobs to BOINC. This project is extending it to support the additional requirements of TACC and nanoHUB. Note that these new capabilities are not specific to TACC or nanoHUB: they provide the glue needed to easily add BOINC-based VC to any existing HTC facility. The team is also developing RPC bindings in several languages (Python, C++, PHP). The other component of the project, Science United, is a database-driven web site and an associated web service for the BOINC clients. Science United will control volunteer hosts (i.e. tell them which projects to work for) using BOINC's "Account Manager" mechanism, in which the BOINC client on each host periodically contacts Science United and is told what projects to run. Project servers, not Science United, will distribute jobs and files. Science United will define a set of "keywords" for science areas (physics, biomedicine, environment, etc.) and for location (country, institution). Projects will be labelled with appropriate keywords. Volunteers will have a yes/no/maybe interface for specifying the types of jobs they want to run. Science United will thus provide a mechanism in which a fraction of total computing capacity can be allocated to a project for a given period. Because total capacity changes slowly over time, this allows near-certain guaranteed allocations. Science United will embody a scheduling system that attempts to enforce allocations, honor volunteer preferences, and maximize throughput. Finally, Science United will do detailed accounting of computing. Volunteer hosts will tell Science United how much work (measured by CPU time and FLOPs, GPU time and FLOPs, and number of jobs) they have done for each project. Science United will maintain historical records of this data for volunteers and projects, and current totals with finer granularity (e.g. for each host/project combination). Finally, Science United will provide web interfaces letting volunteers see their contribution status and history, and letting administrators add projects, control allocations, and view accounting data.