APPENDIX

Glossary of Terminology: The Event Processing Technical Society

(EPTS) Glossary of Terms—Version 2.0

Compiled by

David Luckham & W. Roy Schulte

and

EPTS Glossary Working Group Members:

Jeff Adkins

Pedro Bizarro

H.-Arno Jacobsen

Albert Mavashev

Brenda M. Michelson

Peter Niblett

David Tucker

February 2010

Permission to copy and display this glossary in any medium without fee or royalty is hereby granted, provided that you include the copyright notice as shown herein and link or URL to the Material on the EPTS website.

DISCLAIMERS:

This material is provided “as is,” and the Event Processing Technical Society (EPTS) and its members make no representations or warranties, express or implied, including, but not limited to, warranties of merchantability, fitness for a particular purpose, non-infringement, or title; that the contents of this material are suitable for any purpose; nor that the implementation of such contents will not infringe any third-party patents, copyrights, trademarks, or other rights.

To the fullest extent permitted by applicable law, the EPTS and its members will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of any use of this material or the performance or implementation of the contents thereof.

No other rights are granted by implication, estoppel, or otherwise.

© Copyright 2010 Event Processing Technical Society, All rights reserved.

Acknowledgments: We are indebted to many correspondents who have made contributions, suggestions, and comments over the past year. They are too numerous to mention individually, but we owe them our thanks.—David Luckham, Roy Schulte

PREFACE

Purpose

The purpose of the EPTS glossary of terms is to facilitate industry use of event processing technology by providing a common language for developing applications and software infrastructure that use event processing concepts.

The event processing glossary has three goals:

• Accelerate the learning of the event processing concept
• Further community communication by enabling practitioners to utilize common concepts and terms
• Provide a foundation for analysis and the development of best practices, publications, and industry standards

Organization

The glossary is presented according to the logical order of the terms. An alphabetical listing is available at the beginning of the document for convenience.

Content

This glossary covers a small set of basic terms related to event processing. It will be frequently periodically updated with additional terms in response to suggestions from the event processing community for improvements and additions.

Our approach is to define each term independently of any particular implementation, product, or domain of application. So, for example, the term event object has popular meanings as a tuple, a vector, a row, etc. These are all realizations of events in particular approaches and products. Even the most basic term, event, is problematic. Essentially, there are two distinct meanings:

• An activity that happens
• Something that represents that activity in a computer system

It is tempting to introduce two separate terms such as event and event object. However, in any discussion longer than a paragraph or two, this becomes intolerably clumsy and one finds the distinction being misused, forgotten, or dropped altogether. For example, using the two separate terms would dictate that event processing (see below) should be event object processing. The best solution is to overload the word event. The context of each use becomes the indicator of which meaning is intended. This has been standard practice in the field of event driven simulation for the past thirty years. It was the approach taken by the physicists of the early twentieth century in discussions of relativity where event also has two meanings. We have chosen to follow their example in the knowledge that it did not lead them into ambiguity problems.