I could implement a subscription service that pushed news headers to my
desktop. I request the service once and I consume it every time my
system is turned on.
Logically, this may be a pattern of 'request-consume' yet there is no
direct correlation between a specific request message and any response
message exists. 1 to *.
Duane
Ken Laskey wrote:
> Duane,
>
> Do you have an example in mind?
>
> Ken
>
> At 12:14 PM 4/11/2005, Duane Nickull wrote:
>
>> It is possible to request a service once and consume it multiple
>> times thereafter.
>>
>> Duane Nickull.
>>
>> Christopher Bashioum wrote:
>>
>>> 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:]
>>> Sent: Monday, April 11, 2005 12:34 AM
>>> To: Chiusano Joseph
>>> Cc: Christopher Bashioum;
>>> 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.
>>>
>>> Ken
>>>
>>> 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
>>> requester**.
>>>
>>> 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
>>> request.
>>>
>>> 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
>>> perferred term
>>>
>>> (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
>>> services).
>>>
>>> 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.)
>>>
>>> Thoughts?
>>>
>>> Joe
>>>
>>> Joseph Chiusano
>>> Booz Allen Hamilton
>>> Visit us online@ http://www.boozallen.com
>>>
>>>
>>> -----Original Message-----
>>> From: Christopher Bashioum [mailto:]
>>> Sent: Thursday, April 07, 2005 12:49 PM
>>> To:
>>> 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
>>> own service).
>>>
>>> So...to re-word your statement a little: An entity that
>>> binds
>>> with a service is playing the role of service consumer.
>>>
>>> -----Original Message-----
>>> From: Vikas Deolaliker [mailto:]
>>> Sent: Thursday, April 07, 2005 12:21 PM
>>> To: 'Frank McCabe';
>>> 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
>>> entity that
>>> finds may or may not be the consumer but the entity that
>>> binds is certainly
>>> the consumer.
>>>
>>> So an entity that "binds" with a service would be the
>>> closest
>>> to a service
>>> consumer.
>>>
>>> Vikas
>>>
>>> -----Original Message-----
>>> From: Frank McCabe [mailto:]
>>> Sent: Thursday, April 07, 2005 9:00 AM
>>> To:
>>> 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
>>> business logic
>>> to apply to a service request will depend on many factors:
>>> the means by
>>> which the request was delivered, the request itself and the
>>> person (or
>>> persons) for whom the request was made. This last aspect is
>>> completely
>>> independent of mode of requesting and is purely
>>> business/application
>>> specific.
>>>
>>> Incidentally, the above definition: "an agent that
>>> interacts with a
>>> service in order to achieve a goal" seems to be a
>>> reasonable
>>> definition
>>> of a service requester.
>>>
>>>
>>> On Apr 7, 2005, at 7:23 AM, Gregory A. Kohring wrote:
>>>
>>> Matthew,
>>>
>>> OK, here a fewer other choices which might be deemed
>>> more
>>> "respectful"...
>>>
>>> Service Consumer:
>>>
>>> 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
>>> service.
>>>
>>>
>>> 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...
>>>
>>>
>>> -- Greg
>>>
>>>
>>>
>>> Matthew MacKenzie wrote:
>>>
>>> I think services deserve respect, lets try not to
>>> exploit them :-)
>>> Gregory A. Kohring wrote:
>>>
>>> Thomas,
>>>
>>> Perhaps one should use a somewhat broader
>>> definition
>>>
>>> which captures
>>>
>>> the human user as well:
>>>
>>> Service Consumer: An entity which exploits a
>>> service.
>>>
>>>
>>> -- Greg
>>>
>>>
>>> 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
>>>
>>> "Software that
>>>
>>> invokes an instance."
>>>
>>> Thomas
>>>
>>>
>>>
>>>
>>>
>>> --
>>>
>>> ======================================================================
>>>
>>> G.A. Kohring
>>> C&C Research Laboratories, NEC Europe Ltd.
>>>
>>>
>>> ======================================================================
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> ------------------------------------------------------------------------------------------
>>>
>>> Ken Laskey
>>> MITRE Corporation, M/S H305 phone: 703-883-7934
>>> 7515 Colshire Drive fax: 703-883-1379
>>> McLean VA 22102-7508
>>
>>
>> --
>> ***********
>> Senior Standards Strategist - Adobe Systems, Inc. - http://www.adobe.com
>> Vice Chair - UN/CEFACT Bureau Plenary - http://www.unece.org/cefact/
>> Adobe Enterprise Developer Resources -
>> http://www.adobe.com/enterprise/developer/main.html
>> ***********
>>
>
> --
>
> ---------------------------------------------------------------------------------
>
> / Ken
> Laskey \
> | MITRE Corporation, M/S H305 phone: 703-883-7934 |
> | 7515 Colshire Drive fax: 703-883-1379 |
> \ McLean VA 22102-7508 /
>
> ----------------------------------------------------------------------------------
>
>
>
--
***********
Senior Standards Strategist - Adobe Systems, Inc. - http://www.adobe.com
Vice Chair - UN/CEFACT Bureau Plenary - http://www.unece.org/cefact/
Adobe Enterprise Developer Resources - http://www.adobe.com/enterprise/developer/main.html
***********
