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Subject: Re: [soa-rm] Types of Services (RE: [soa-rm] Definition of"Service Consumer")
Ken and Joe,
do all services have a 2-way communication mechanism, or is it possible to have a service that just consumes messages (or just sends messages)? The reason I am asking, is that it looks like all the interactions mentioned so far involve a request and a response, but I am wondering about the idea of events or broadcasts.
From: Ken Laskey [mailto:firstname.lastname@example.org]
Sent: Monday, April 11, 2005 12:34 AM
To: Chiusano Joseph
Cc: Christopher Bashioum; email@example.com
Subject: Re: [soa-rm] Types of Services (RE: [soa-rm] Definition of "Service Consumer")
Let me suggest the following:
A data resource is a source of content. It accepts a request and returns a value or set of values in response. The return can be an entity (such as a particular schema), an attribute of an entity (such as when the schema was last modified), or any numerical or textual value or set of values. The content can be static objects stored in some repository or dynamically generated through the use of a processing resource. Data about a missile that is stored in a database is content. The weather forecast for tomorrow is content generated from a weather simulation. In a net-centric environment, the requester does not know the format from which the response is retrieved or how it is generated.
A processing resource is one that accepts a task and return a status indicating the extent to which the task was completed and information on how the state of entities changed as a result of the processing. One or more processing resources may be invoked as part of a process of submitting a query and being returned a response. From the standpoint of a user (either human or machine), it is unimportant what combination of data and processing resources are invoked as long as the request is satisfied.
Services interact with (i.e. use, invoke, access, ...) these resources.
On Apr 10, 2005, at 2:00 PM, Chiusano Joseph wrote:
I wonder if the roles a service can play - or, perhaps one can say, the
general types of services that can exist - have any bearing on our RM at
all, in an indirect way.
Put in simple terms, one may say that there are - in general - 3
overarching "types" of services. These correspond to 3 of the layers of
the general "integration stack" (data, application, and process):
(1) Data-Oriented Service: Primary role is to accept and process data,
or provide data based upon a request.
Two general types:
(a) Data Processor*: Accepts as input a set of data, processes that
data, and (optionally) sends a response. The response may simply be an
acknowledgement, or another set of data to be processed by the service
Ex: Simple form acceptance service, such as a loan application form
service acting on behalf of multiple banks (routes to proper bank and
sends back acknowledgement to form submitter)
(b) Data Provider: Provides streaming data, or a set of data upon
Ex's: RSS news feed (streaming data), stock quote (set of data upon
request - given stock ticker symbol)
*need better term - using this for illustration purposes only
**using term "requester" for now since we have not established our
(2) Application-Oriented Service (aka "Function-Oriented Service"):
Primary role is to accept a command and carry out processing based on
that command, in a singular fashion (i.e. does not invoke other
Ex's: Inventory verification service (accepts item #, responds with
whether or not it is in inventory), shipment cost calculation service
(3) Process-Oriented Service: Similar to Application-Oriented Service,
but invokes other services in carrying out its processing (i.e. it
embodies the definition of an overarching process).
Ex: Order processing service (checks customer credit, checks inventory,
does shipment cost calculation, etc.)
Booz Allen Hamilton
Visit us online@ http://www.boozallen.com
From: Christopher Bashioum [mailto:firstname.lastname@example.org]
Sent: Thursday, April 07, 2005 12:49 PM
Subject: RE: [soa-rm] Definition of "Service Consumer"
When we talk about service consumer vs. provider in this
sense, I think we need to separate the "static" entity from
the dynamic role that said entity plays. A given entity can
be both service provider (in which case it publishes it's
service description) and service consumer (in which case it
binds to another service provider in order to accomplish its
So...to re-word your statement a little: An entity that binds
with a service is playing the role of service consumer.
From: Vikas Deolaliker [mailto:email@example.com]
Sent: Thursday, April 07, 2005 12:21 PM
To: 'Frank McCabe'; firstname.lastname@example.org
Subject: RE: [soa-rm] Definition of "Service Consumer"
Using the publish/find/bind framework of SOA...
The entity that publishes is certainly not the consumer. The
finds may or may not be the consumer but the entity that
binds is certainly
So an entity that "binds" with a service would be the closest
to a service
From: Frank McCabe [mailto:email@example.com]
Sent: Thursday, April 07, 2005 9:00 AM
Subject: Re: [soa-rm] Definition of "Service Consumer"
There is a distinction between the software *entity*
(agent/component/J2EE bean/.../) that interacts with a
service in order
to achieve some goal, and the person or persons for whom that
interaction is taking place.
The reason that this distinction is important is similar to the
distinction between a service interface and the service itself:
accessing your bank account from an ATM or on-line will use different
interfaces but ultimately all use the same service.
Here is an example of why its important: the appropriate
to apply to a service request will depend on many factors:
the means by
which the request was delivered, the request itself and the
persons) for whom the request was made. This last aspect is
independent of mode of requesting and is purely business/application
Incidentally, the above definition: "an agent that interacts with a
service in order to achieve a goal" seems to be a reasonable
of a service requester.
On Apr 7, 2005, at 7:23 AM, Gregory A. Kohring wrote:
OK, here a fewer other choices which might be deemed more
1) End-user of a service.
2) An agent which, acting on behalf of its owner, uses a service.
3) An entity which utilizes a service
4) An entity which consumes the product or information produced by a
Note all of these definitions depend upon the definition of the
term "service". Have we agreed on this already? Perhaps we should
start there first...
Matthew MacKenzie wrote:
I think services deserve respect, lets try not to exploit them :-)
Gregory A. Kohring wrote:
Perhaps one should use a somewhat broader definition
the human user as well:
Service Consumer: An entity which exploits a service.
Thomas Erl wrote:
Now that we've decided on the term "service consumer" it may be
useful to formally define it. The term "consumer" is used by the
WS-I Basic Profile wherein it is simply defined as
invokes an instance."
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