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Subject: [no subject]
An SOA without registry by definition is limited and private
An SOA with a registry is open and dynamic
John
-----Original Message-----
From: Chiusano Joseph [mailto:chiusano_joseph@bah.com]
Sent: Wednesday, December 15, 2004 9:01 AM
To: Matthew MacKenzie; ebSOA OASIS TC
Subject: RE: [ebsoa] Does SOA Require Registry-Based Dynamic Discovery?
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:mattm@adobe.com]
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:chiusano_joseph@bah.com]
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
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>My main beef with “registry”
is that it is entirely too prescriptive. I prefer to refer to the
mechanism we currently define as a registry as a “discovery mechanism”.
It is possible, for example, to do public service discovery using the DNS
system (DNS-SD), or its private equivalent (mDNS).<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>It just so happens that “registry”
is a good way of discovering services, but not the only way we could/should
perform such discovery.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>-matt<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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face="Times New Roman"><span style='font-size:12.0pt'>
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</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Yunker, John
[mailto:yunker@amazon.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 15, 2004
12:06 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Chiusano Joseph; Matthew
MacKenzie; ebSOA OASIS TC<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [ebsoa] Does SOA
Require Registry-Based Dynamic Discovery?</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>From my view the "registry
requirement" is more a function of the distributed nature of the
participants, the number and type of services, and the amount of change.
A registry provides a method for decoupling "the use of an SOA" from
"direct communication of the participants about HOW to use the
SOA".</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>An SOA without registry by definition is
limited and private</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>An SOA with a registry is open and dynamic</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>John</span></font><o:p></o:p></p>
</div>
<blockquote style='margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> Chiusano Joseph
[mailto:chiusano_joseph@bah.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 15, 2004
9:01 AM<br>
<b><span style='font-weight:bold'>To:</span></b> Matthew MacKenzie; ebSOA OASIS
TC<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [ebsoa] Does SOA
Require Registry-Based Dynamic Discovery?</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks Matt. From that I take:</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>- Discovery in general is required for SOA (cannot function
without it)</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>- Whether it is (what I will call) "fundamental"
discovery - meaning your first example below - or "registry-based"
discovery depends on technical and business requirements.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>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".</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Kind Regards,</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Joseph Chiusano</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Booz Allen Hamilton</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Strategy and Technology Consultants to the World</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<blockquote style='border:none;border-left:solid black 1.5pt;padding:0in 0in 0in 4.0pt;
margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabIndex=-1>
</span></font></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Matthew
MacKenzie [mailto:mattm@adobe.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 15, 2004
11:57 AM<br>
<b><span style='font-weight:bold'>To:</span></b> Chiusano Joseph; 'ebSOA OASIS
TC'<br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [ebsoa] Does SOA
Require Registry-Based Dynamic Discovery?</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>My opinion is that a registry is nothing
more than a very explicit service discovery device.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>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:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>{<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>
Services imap, http, ssh, daytime, pop3, portmap<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>
IPRange 192.168.0.0/24<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>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.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Contrast this with a registry driven SOA:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>{ <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>
ServiceRegistry http://foo/registry<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>The only difference is in the
implementation detail and verbosity of information available. Conceptually,
they are the same.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>--Matt MacKenzie<o:p></o:p></span></font></p>
<div>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabIndex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Chiusano Joseph
[mailto:chiusano_joseph@bah.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 15, 2004
11:38 AM<br>
<b><span style='font-weight:bold'>To:</span></b> ebSOA OASIS TC<br>
<b><span style='font-weight:bold'>Subject:</span></b> [ebsoa] Does SOA Require
Registry-Based Dynamic Discovery?</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>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.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>For example, suppose that:</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>- 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). </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>- 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</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>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?</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Kind Regards,</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Joseph Chiusano</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Booz Allen Hamilton</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Strategy and Technology Consultants to the World</span></font><o:p></o:p></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
</blockquote>
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