Thanks Matt. From that I take:
-
Discovery in general is required for SOA (cannot function without
it)
-
Whether it is (what I will call) "fundamental" discovery - meaning your first
example below - or "registry-based" discovery depends on technical and business
requirements.
I
just cannot foresee trying to convince a current or potential customer that they
have to put up $XX,XXX for a registry product if the technical and business
requirements do not call for it, just to comply with someone's definition of the
term "SOA".
Kind Regards,
Joseph Chiusano
Booz Allen Hamilton
Strategy and Technology Consultants to
the World
From: Matthew MacKenzie
[mailto:]
Sent: Wednesday, December 15, 2004 11:57
AM
To: Chiusano Joseph; 'ebSOA OASIS TC'
Subject: RE:
[ebsoa] Does SOA Require Registry-Based Dynamic
Discovery?
My opinion is that a
registry is nothing more than a very explicit service discovery
device.
An SOA does need a
method of discovering services, and consuming them, but this method may in
some cases be subtle. For example, my SOA may operate on the premise
that consumers all are aware of an enumeration of service types, and their
port numbers (think /etc/services in the unix world), and allowable IP ranges
for finding services. Clients may be configured something
like:
{
Services imap, http, ssh, daytime, pop3, portmap
IPRange 192.168.0.0/24
}
A client with such a
configuration does have a way of discovering services that are available to
it, and of course, a way of binding to them.
Contrast this with a
registry driven SOA:
{
ServiceRegistry http://foo/registry
}
The only difference
is in the implementation detail and verbosity of information available.
Conceptually, they are the same.
--Matt
MacKenzie
From:
Chiusano Joseph [mailto:]
Sent: Wednesday, December 15, 2004 11:38
AM
To: ebSOA OASIS
TC
Subject: [ebsoa] Does SOA
Require Registry-Based Dynamic Discovery?
What is the TC's opinion on the
answer to the question of "does SOA require registry-based dynamic discovery"?
I know that Discovery is a pattern in the .047 spec, which leads me to believe
that the position is that SOA does not *require* registry-based
discovery.
For example, suppose
that:
- 2 organizations are using Web
Services in a "SOA-like" manner (meaning shared services represented as Web
Services, that are invoked by other Web Services).
- There is no registry-based
dynamic discovery, perhaps because the organizations agree that these service
locations are completely (or relatively) stable, and that if the locations
change, there will be some out-of-band mechanism for propagating updated WSDL
documents
Are these 2 organizations
therefore *not* using a service-oriented architecture? That is, does the
second point completely negate the first? Or, is it all really a matter of
business and technical requirements?
Kind
Regards,
Joseph
Chiusano
Booz Allen
Hamilton
Strategy and Technology
Consultants to the World
