III: Medium: Scalable and Secure Database as a Service

CirrusDB项目寻求解决在构建“数据库即服务”时出现的几个关键挑战。这种服务的目标是为许多应用程序提供一个SQL接口，存储今天可能分布在数百或数千个独立的数据库管理系统中的数据。这很有吸引力，因为单个用户在软件许可、硬件、管理和能源方面的成本可以大大降低，因为可以将许多不同的数据库多路传输到更小的占地面积上。此外，成本可以与实际使用量成比例，从而节省了应用程序开发人员的大量前期投资。CirrusDB的智力优势与这一领域的三个关键挑战有关：1)多租户，在这种情况下，监控一组复杂的数据库工作负载的资源使用情况，并将数据库整合到最少数量的物理机上，同时确保性能隔离和实时迁移，而不会停机。与大规模多租户的现有工作不同，CirrusDB尝试共同定位具有类似模式的租户，这些租户的资源利用配置文件不会超过托管它们的计算机的容量。2)可伸缩性，其中查询处理(和相应的数据)的责任在服务中的多个节点之间划分，以实现高吞吐量。3)DBaaS基础设施执行应用程序对加密数据发出的SQL查询，从而实现对完全私有数据的完整SQL处理。CirrusDB将产生广泛的影响，因为它将产生广泛的数据库解决方案，使大型多节点数据库服务既可以部署在公共云上，也可以部署在私有数据中心中，从而为SQL查询执行提供多租户、使用自动分区的横向扩展和隐私保护。这将大大降低运行大型数据库所需的行政和资本成本。CirrusDB还将降低使用数据库的应用程序的进入门槛，因为即使在需要高事务性能的情况下，也不需要拥有内部数据库专业知识。有关更多信息，请参阅项目网站的网址：http://db.csail.mit.edu/cirrusdb/

The CirrusDB project seeks to address several key challenges that arise when building a "database as a service". The goal of such a service is to provide a SQL interface to many applications, storing data that today might be spread across hundreds or thousands of separate database management systems. This is attractive because the costs incurred by individual users in the form of software licensing, hardware, management, and energy can be substantially lowered because it will be possible to multiplex many different databases onto a smaller footprint. Moreover, the costs can be made proportional to actual usage, saving significant up-front investments by application developers. The intellectual merit of CirrusDB relates to three key challenges in this area:1) Multi-tenancy, in which the resource use of a complex set of database workloads are monitored and the databases are consolidated on to a minimum number of physical machines while ensuring performance isolation and live migration with no downtime. Unlike existing work on large-scale multi-tenancy, which has focused on co-locating tenants with similar schemas, CirrusDB attempts to co-locate tenants which have resource utilization profiles that will not exceed the capacity of the machine on which they are hosted.2) Scalability in which the responsibility for query processing (and the corresponding data) is partitioned amongst multiple nodes in the service to achieve high throughput, using a novel graph partitioning strategy.3) In which the DBaaS infrastructure executes SQL queries issued by applications over encrypted data, enabling complete SQL processing over fully private data. The key idea is to use the notion of "adjustable security" by encrypting the data in layers in a way that allows not just equality checks but also range queries, sorting operations, and joins to be executed efficiently.CirrusDB will have broad impact in that it will result in database solutions that will a enable large, multi-node database service to be deployed both on a public cloud as well as in private data centers, providing multi-tenancy, scale-out using automatic partitioning, and privacy for SQL query execution. This will result in significantly lower administrative and capital costs required to run large-scale databases. CirrusDB will also reduce the barrier to entry for applications that use databases, because it will not be necessary to have in-house database expertise even when one needs high transactional performance.For further information see the project web site at the URL: http://db.csail.mit.edu/cirrusdb/