A formal model for reasoning about adaptive QoS-enabled middleware
A formal model for reasoning about adaptive QoS-enabled middleware
复制标题
用于推理支持自适应 QoS 的中间件的正式模型
DOI：
10.1145/1005561.1005564
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
G. Agha
中科院分区：
文献类型：
--
作者：
N. Venkatasubramanian;C. Talcott;G. Agha
提供分布式多媒体服务的系统经历了不断的演变；需要可定制的中间件来有效地管理这种变化。用于资源管理的中间件服务彼此并行执行，并与应用程序活动并发执行，因此可能相互干扰。为了在分布式多媒体系统中保证高性价比的服务质量，资源管理服务的安全可组合性是必不可少的。基于并发活动对象的角色模型，提出了一种面向可定制服务质量中间件的元体系结构框架--两级角色模型(TLAM)。使用TLAM，一个描述和推理开放分布式系统组件的语义模型，我们展示了如何使用一个服务质量代理服务来安全、灵活和高效地协调多媒体资源管理服务。具体地说，我们展示了一个系统，其中的多媒体参与者的行为满足指定的要求，并提供所需的多媒体服务。行为规范为资源管理提供了多种算法的可能性。此外，识别了足以保证多个代理资源管理服务之间不干扰的约束，以及为附加服务的安全组合提供指导。
Systems that provide distributed multimedia services are subject to constant evolution; customizable middleware is required to effectively manage this change. Middleware services for resource management execute concurrently with each other, and with application activities, and can, therefore, potentially interfere with each other. To ensure cost-effective QoS in distributed multimedia systems, safe composability of resource management services is essential. In this article, we present a meta-architectural framework, the Two-Level Actor Model (TLAM) for customizable QoS-based middleware, based on the actor model of concurrent active objects. Using TLAM, a semantic model for specifying and reasoning about components of open distributed systems, we show how a QoS brokerage service can be used to coordinate multimedia resource management services in a safe, flexible, and efficient manner. In particular, we show a system in which the multimedia actor behaviors satisfy the specified requirements and provide the required multimedia service. The behavior specification leaves open the possibility of a variety of algorithms for resource management. Furthermore, constraints are identified that are sufficient to guarantee noninterference among the multiple broker resource management services, as well as providing guidelines for the safe composition of additional services.