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Subject: RE: [soa-rm] Types of Services (RE: [soa-rm] Definitionof"Service Consumer")
Duane, I don't want to harp on this but for terminology sake... I suggest that while one receives information related to an "originally consumed service", that the service is actually in the process of being consumed until one end terminates it, regardless of the communication protocol used. Further (and this is a general comment) I firmly believe that if we do not define service and SOA within the context of time (amongst a host of other domains as a set of constraints) the model will be too thin to be viable. For example, security is a domain that need not be concretely defined except as a set of constraints(s1, s2, s3...) where, say s1 is the authentication constraint, that bound the system but allow for infinite derivations. We cannot ignore reality, but we can describe it abstractly and we must be able to show we have considered those things that keep dragging us into the concrete (nice pun here) Wes -----Original Message----- From: Duane Nickull [mailto:dnickull@adobe.com] Sent: April 14, 2005 1:03 PM To: McGregor, Wesley Cc: klaskey@mitre.org; cbashioum@mitre.org; soa-rm@lists.oasis-open.org Subject: Re: [soa-rm] Types of Services (RE: [soa-rm] Definitionof"Service Consumer") Wesley: This would probably be true if one assumed the exclusive use of synchronous communication where sockets remained open at both ends, however I would assert that using asynchronous communication patterns, it physically represents more than one response per request if a socket if opened, used, then closed for each response. However, a counterpoint to my own point is that logically, I have invoked a service and "consume" entails all subsequent activity sent from the service to the consumer, regardless of the number of responses to the single request. In this respect, your observation would be correct. Luckily we probably don't have to worry about this unless it is directly relevant in terms of the RM. Duane McGregor.Wesley@tbs-sct.gc.ca wrote: >I finally got to this message and I have to take issue on the terminology.. > >I would suggest Duane that you have consumed the service only once but the longevity of the response is bounded but infinite. > >I think the issue of time needs to be considered as a fundamental component to our reference model. > >I apologize to all those who may have already sorted this issue out. > >Wes > > > -----Original Message----- >From: Duane Nickull [mailto:dnickull@adobe.com] >Sent: April 11, 2005 2:34 PM >To: Ken Laskey >Cc: Christopher Bashioum; soa-rm@lists.oasis-open.org >Subject: Re: [soa-rm] Types of Services (RE: [soa-rm] Definition of"Service Consumer") > >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 ***********
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