CORBA系统中截获机制研究与实现

Portable interceptors in CORBA

截获机制是CORBA系统集成新服务的规范的方法 .介绍了截获机制产生的背景 ,分析了截获机制的原理和截获点的定义及其功能 ,指明了截获机制的核心在于如何在客户方和服务器方之间获得并且传递ORB核心内部信息 ,截获器贯穿从对象创建到服务响应的整个系统调用过程 ,并明确了在扩展新服务时要正确使用截获点所需遵循的语义规则 .在此研究基础上 ,提出并实现了遵循可移植截获器规范的PI ORBUS系统方案 .针对该方案实现系统的性能测试结果 ,分析了服务器响应时间与截获实例数量之间的关系 ,探讨了影响服务器响应时间的主要因素 。

Interception mechanism is a universal way for CORBA systems to integrate new services. Background is introduces firstly. Specification of portable interceptors is studied and philosophy of interception mechanism is analyzed. Interceptor points and their corresponding functions are given. This paper manifests that the core of interception mechanism is how to obtain and transfer ORB information among clients and servers. Therefore, interceptors go through whole CORBA invocation procedure, from object creation to service reply. It also points out semantics rules necessarily abided by interceptors for new services. Based on these research results, a prototyped system called PI-ORBUS is designed and developed. With performance test results of PI-ORBUS, the paper shows the relationship between server response time and number of interceptors in a system. Main factors affecting performance are picked up. Furthermore potential ways to optimize such a system are discussed.