W3C Push Workshop, 8-9 September 1997

[Other Papers] [Briefing Package]

Abstract for W3C Workshop on Push Technology

Jim Randell // Hewlett-Packard Laboratories, Bristol, UK // <jmr@hplb.hpl.hp.com>

The Keryx Notification System


The Keryx Programme in Hewlett-Packard Laboratories, Bristol, has developed a real-time, notification system for distributing announcements of changes in the dynamic content of Internet-based services. The Keryx Notification System provides an architecture and supporting components that allows the rapid development, deployment and evolution of services in a distributed environment.

The Keryx system supports the real-time exchange of structured information (a notification) between service providers and service users. The communication model allows "unsolicited" (or informational) information to be passed to users based on their predefined "interests". Users define their interests by registering a filter that is applied to all notifications. Notifications satisfying the filter are sent to the user, thus services can be flexibly developed without the notification source or the user having prior knowledge of each other.

A notification is a self-contained, non-directed package of structured information reflecting the occurrence of some event. For example, a notification may be generated when Email arrives on a mail server, or when the content of a Web page is updated. Interested consumers may register an interest in such events and will be notified as the events happen, allowing the content itself to be retrieved using normal services (POP and HTTP in the above examples).

The Keryx Notification System provides a real-time, update service that saves the need for regular polling of the original content. This can support a host of Internet-based services.

System Principles


A Java based implementation of the Keryx Notification System will be available in the near future from the KeryxSoft WebSite at <URL:http://keryxsoft.hpl.hp.com/>.