2008/12/5 Udi Dahan <[EMAIL PROTECTED]>:
> I'd argue that the windowing system example is Interrupt driven, rather than
> event driven. That being said, I agree with your statement:

Potentially true with MS windows but X Windows was certainly event
based, hence the HMVC model.

>
>
>
>> Getting "order placed" to interested parties does not need to be via
>> pub/sub. Or at least, not necessarily via a message broker.
>
>
>
> However, I'd assert that there are advantages to a pub/sub approach over a
> non-pub/sub approach, not the least being that additional subscribers can be
> added into the ecosystem without changes to pre-existing members.

Which is where pub/sub works, the point is that EDA doesn't have to be
pub/sub and that pub/sub works in certain cases (broadcasts being a
good example).  In other words you need a flexible approach that uses
lots of different technology solutions to cover all of your business
problems.

>
>
>
> The crux is, IMO, what is the semantic thing that you are pub/sub-ing?
>
>
>
> If the thing represents a business event (past tense), like order placed,
> customer billed, etc, I'd say that pub/sub is a very good solution.
>
> If the thing represents a command (imperative, present tense) like place
> order, bill customer, etc, I'd say that pub/sub is a poor solution.
>
>
>
> I'd like to submit we might call this join of business events, pub/sub, EDA,
> and SOA an Event Service Architecture, or ESA, just as a convenience for
> comparing approaches.

Another new name....  the principle is sound however (IMO).

Steve

>
>
>
> Thoughts?
>
>
>
> --
>
> Udi Dahan - The Software Simplist
>
>
>
> From: [email protected]
> [mailto:[EMAIL PROTECTED] On Behalf Of Rob
> Eamon
> Sent: 04 December 2008 20:29
> To: [email protected]
> Subject: [service-orientated-architecture] Re: Roch Clarifies Some Key Terms
>
>
>
> Which is primarily an issue brought to the fore in a pub/sub approach.
>
> EDA != pub/sub. For example (very low-level), windowing systems are
> event driven (mouse clicked, window closed, etc.) but are not pub/sub.
>
> Getting "order placed" to interested parties does not need to be via
> pub/sub. Or at least, not necessarily via a message broker. IMO,
> pub/sub is often used in interactions when it shouldn't be. Indeed, IMO
> pub/sub is rarely the right mechanism to use.
>
> -Rob
>
> --- In [email protected], "Steve Jones"
> <[EMAIL PROTECTED]> wrote:
>>
>> And then when you add in non-repudiation you have a whole other set
>> of challenges.
>>
>> Steve
>
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