Friday, December 12, 2008

More On Event Representation

CAC Japan is the only Japanese member of EPTS, some of their team have participated in the EPTS 4th Event Processing Symposium. One of the missions they have talked upon themselves the task to bring the event processing ideas and concepts of event processing closer to the Japanese market, they have sent me the URL of their Japanese portal
and in specific they have translated the EPTS glossary to Japanese
I salute the initiative, we indeed need to reach out for more parts of the universe. I don't understand the Japanese part of the site, but trust the CAC team. Hope to have an opportunity to visit Japan some day.

The issue of translation from language to language reminded me about the still chaotic situation in the area of event representation on which I have blogged about a year ago.

Much of the existing event processing systems see the event representation as an internal issue and make their own decision about which structure should be supported: flat positional like 1-NF in relational database, tagged semi-structured (XML), or Java objects. Furthermore the "header" of an event varies. This reminds me a discussion a few years ago with some of my IBM colleagues who worked on standard for management events. They included "managed entity" and "severity" as mandatory attributes, since in their domain -- event is always a reported problem. We explained them that there are other types of events, e.g. money withdrawal. For this type of event there is no severity and no "managed entity". This has been a funny discussion since they did not really think that what we are talking about is event, however, in their domain, what they have done made perfectly sense. This leads to a thought that we may have several layers of attributes:

  • Universal attributes that should be mandatory in any event --- there should be very few of them --- Marco from RuleCore has suggested in his recent Blog:
  • Id - every event is unique and have an unique id.
  • Type - Every event is of a specific type.
  • Detection time - every event is detected at a specific time.
  • Entity id - The entity that changed its state.
I agree to the first three, but not every event changes the state of a single entity, and in
some cases (e.g. derived events) it is not really important which entity changes it state, so I
would move the "Entity id" to the next category.
  • Domain common attributes (which also may have several level of domain, sub-domain, sub-sub-domain etc...) -- this may include: event-location, entity that changed its state, time-zone, severity and much more.
  • Event type specific attributes -- individual for each event type. Some of them may be reference to entities, some descriptive attributes.
There is even more interesting discussion about derived events - but I'll defer it to one of the next postings.

1 comment:

Anonymous said...

Hi Opher,
Thank you very much for referenceing cep-jp in your famous blog.
We intend the site to be educational and vendor neutral. Any contribution (articles, presentation,etc) that fits the purpose is very welcome.
We are looking for your help.
Abdelftah Elhabib
CAC Japan