WebFrame:一种多层次可扩展的Web应用服务器

WebFrame:An Extensible Multi-layer Web Application Server

网络软件平台已成为当今软件技术发展的主流趋势和竞争焦点 .Web应用服务器是Web计算环境下产生的新型中间件 ,是网络软件平台的关键与核心 ,已逐步成为信息化基础软件设施之一 .该文重点介绍自主研制的WebFrame应用服务器的设计方法和思路 ,并分析了WebFrame的关键实现技术 ,给出了相应的解决办法 .针对目前主流Web应用服务器存在的开放性和灵活性低等不足之处 ,WebFrame的设计遵循一种开放工程的方法 ,采用基于微内核的多层次可扩展模型 ,使得WebFrame具备在其生命周期内支持不同级别定制和可重配置的能力 ,满足不断变化的QoS需求 .对比测试数据表明WebFrame具有较好性能 .

Web application servers (WASs) are middleware platforms for deployment and execution of component-based web applications. To cater for an increasingly diverse range of QoS demands, WAS must be capable of adaptation during execution to modify itself and to respond to changing conditions in its external environment. To accommodate such changes, WAS should provide both deployment-time configurability and run-time reconfigurability. Unfortunately, most of the mainstream web application servers adopt a monolithic architecture and black box philosophy to their design, and fail to properly address such requirements. In our point of view, reconfigurability of WASs should be available at any time of the whole lifecycle. In this paper, an extensible multi-layer model that supports multi-phase extension using computational reflection, microkernel, and component techniques is proposed for web application servers. The model is structured into four layers. Both deployment-time configuration and run-time reconfiguration at multiple layers is supported in this model. The model is applied in the design and implementation of a WAS, referred to as WebFrame. The comparative evaluation of the performance impact of reflection and multi-phase extension on systems are given. The experiments show that WebFrame takes on good performance.