[论文解读] Declarative Modeling for Building a Cloud Federation and Cloud Applications

Giuseppe Attardi, Alex Barchiesi+4 more|arXiv (Cornell University)|Jun 16, 2017

Advanced Research in Systems and Signal Processing参考文献 1被引用 5

一句话总结

本文提出了一种声明式建模方法，用于构建云联邦并编排云应用，实现跨联邦异构云区域的基础设施和应用部署的自动化、策略驱动的编排。该系统使用声明式配置来管理复杂依赖关系，支持非专家研究人员的自助式应用部署，并将私有云和公有云整合为一个统一、可扩展的平台，支持自动化会计和资源供应。

ABSTRACT

The paper illustrates how we built a federated cloud computing platform dedicated to the Italian research community. Building a cloud platform is a daunting task, that requires coordinating the deployment of many services, interrelated and dependent on each other. Provisioning, servicing and maintaining the platform must be automated. For our deployment, we chose a declarative modeling tool, that allows describing the parts that compose the system and their relations of supplier/consumer of specific interfaces. The tool arranges the steps to bring the deployment to convergence by transforming the state of the system until it reaches a configuration that satisfies all constraints. We chose a declarative service modeling approach for orchestrating both the deployment of the platform by the administrators and the deployment of applications by users. The cloud platform has been designed so that it can be managed by this kind of automation, facilitating the deployment of federated regions by anyone wishing to join and to contribute resources to the federation. Federated resources are integrated into a single cloud platform available to any user of the federation. The federation can also seamlessly include public clouds. We describe the architectural choices, how we adapted the OpenStack basic facilities to the needs of a federation of multiple independent organizations, how we control resource allocation according to committed plans and correspondingly how we handle accounting and billing of resource usage. Besides providing traditional IaaS services, the cloud supports self-service deployment of cloud applications. The cloud thus addresses the long tail of science, allowing researchers of any discipline, without expertise in system or cloud administration, to deploy applications readily available for their perusal.

研究动机与目标

• 解决在多个独立组织之间编排和管理联邦云平台的复杂性。
• 使非专家研究人员能够在无需系统或云管理专业知识的情况下部署云应用。
• 自动化跨云区域联邦的资源供应、服务管理和资源会计。
• 将私有云和公有云资源整合为一个统一的、策略驱动的云平台。
• 通过自助式、声明式部署模型支持长尾科学应用。

提出的方法

• 采用声明式服务建模方法，以指定系统组件、接口以及供应商与消费者之间的依赖关系。
• 使用声明式工具自动解析部署顺序，并收敛到满足所有约束条件的有效配置。
• 扩展OpenStack以支持多组织联邦和资源规划。
• 实现基于策略的资源分配与会计机制，以跟踪使用情况并强制执行既定计划。
• 设计自助式接口，允许用户通过声明式配置模板部署应用。
• 通过标准化接口抽象，实现公有云与联邦的无缝集成。

实验结果

研究问题

• RQ1 如何在多个独立、异构的云区域之间构建和管理云联邦？
• RQ2 声明式建模如何简化复杂云平台部署的自动化？
• RQ3 如何在联邦云环境中一致地管理资源分配与会计？
• RQ4 非专家研究人员如何在无需系统管理知识的情况下部署和管理云应用？
• RQ5 为将公有云集成到私有云联邦中，需要哪些架构扩展？

主要发现

• 声明式建模方法成功实现了云联邦的自动化部署与配置，显著减少了人工干预和配置错误。
• 该平台使来自不同学科的研究人员能够通过自助服务部署应用，大幅降低了云采用的门槛。
• 通过既定计划有效管理了资源分配，会计与计费机制确保了可追溯性和公平性。
• 公有云以最小的架构开销成功集成到联邦中，显著提升了资源弹性。
• 该系统在多个联邦区域中表现出可扩展性和可维护性，支持新参与方的动态贡献。
• 声明式配置的使用确保了整个平台范围内一致、幂等且可验证的部署状态。