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Subject: Re: [soa-rm] Types of Services (RE: [soa-rm] Definition of "Service Consumer")
So the question is whether a subscription service is fundamentally
different from other services. Need to chew on that.
Ken
At 02:33 PM 4/11/2005, Duane Nickull wrote:
>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:klaskey@mitre.org]
>>>> Sent: Monday, April 11, 2005 12:34 AM
>>>> To: Chiusano Joseph
>>>> Cc: Christopher Bashioum; soa-rm@lists.oasis-open.org
>>>> 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:cbashioum@mitre.org]
>>>> Sent: Thursday, April 07, 2005 12:49 PM
>>>> To: soa-rm@lists.oasis-open.org
>>>> 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:vikas@sonoasystems.com]
>>>> Sent: Thursday, April 07, 2005 12:21 PM
>>>> To: 'Frank McCabe'; soa-rm@lists.oasis-open.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
>>>> 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:frank.mccabe@us.fujitsu.com]
>>>> Sent: Thursday, April 07, 2005 9:00 AM
>>>> To: soa-rm@lists.oasis-open.org
>>>> 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
>***********
>
--
---------------------------------------------------------------------------------
/ Ken
Laskey \
| MITRE Corporation, M/S H305 phone: 703-883-7934 |
| 7515 Colshire Drive fax: 703-883-1379 |
\ McLean VA 22102-7508 /
----------------------------------------------------------------------------------
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