Abstract

In this paper, we present the design of COBEA - a COrba-Based Event Architecture. A service that is the source of (parameterised) events publishes in a Trader the events it is prepared to notify, along with its normal interface specification. For scalability, a client must register interest (by invoking a register method with appropriate parameters or wild cards) at the service, at which point an access control check is carried out. Subsequently, whenever a matching event occurs, the client is notified.

We outline the requirements on the COBEA architecture, then describe its components and their interfaces. The design and implementation aim to support easy construction of applications by using COBEA components. The components include event primitives, an event mediator and a composite event service; each features well-defined interfaces and semantics for event registration, notification and filtering. We demonstrate that COBEA is flexible in supporting various application scenarios yet handles efficiently the most common event communications. The performance of server-side filtering for various registration scenarios is presented. Our initial experience with applications is also described.

• View the full text of this paper in HTML and PDF form.

• If you need the latest Adobe Acrobat Reader, you can download it from Adobe's site.

• To become a USENIX Member, please see our Membership Information.