RE: Question regarding the availability of services (and resources)

SOAP-POWDER? That will never wash... 

Hi Michael - I would have thought the use case below was more
efficiently dealt with in either the transport layer (load balancer
configurations) or in front-end application logic (e.g. HTTP
proxy/Access layer/Application container) than with a POWDER DR.  

Cheers
Kevin



-----Original Message-----
From: public-powderwg-request@w3.org
[mailto:public-powderwg-request@w3.org] On Behalf Of Phil Archer
Sent: 20 July 2007 11:32
To: Hausenblas, Michael
Cc: SWD WG; public-powderwg@w3.org
Subject: Re: Question regarding the availability of services (and
resources)


Michael,

I may have misunderstood but I'm not sure that POWDER is the best helper

here. We deal with generalised metadata that can be applied to lots of 
things at once rather than the sort of use case you describe.

That said, I can see that we're going to face the same issue before 
long. Some of us are working on a project that will see a service that 
will handle Description Resources and talk to its clients over SOAP (the

inevitable SOAP-POWDER made manifest...) but if our service is slow, 
clients will want to talk to a mirror or some other service. Hmmm... 
maybe this is a job for the Rule Interchange Format folk 
(http://www.w3.org/2005/rules/)?

Phil.

Hausenblas, Michael wrote:
> 
> All,
> 
> I've got a (maybe dumb) question regarding the availability of
> services (and resources), or better say how to describe and handle
this.
> This may as well concern the 'Best Practice Recipes for Publishing RDF
> Vocabularies' deliverable [1], but might also touch POWDER-WG [2]
issues
> -
> I'm unsure about it ...
> 
> 
> Now, here comes our problem. When developing SW applications, we
> frequently 
> encounter the following situation: Say, there are two external
services
> A and B.
> In our SW application I'd like to state that per default service A
> should be used,
> but in case A is not available (or has too big latency), service B
must
> be used.
> 
> What I've gathered so far (but I must admit, I did not read each and
> every post in all the mailing lists ;) is that:
> 
> + The 'POWDER: Use Cases and Requirements' document [3] also tackles
>   this issues, IMHO, but I can't find a hook for our problem;
> 
> + The Web Services Policy Working Group [4] has published a policy
>   model in its 'Web Services Policy 1.5 - Framework' [5]; though AFAIK
>   this is not based on RDF, and I don't know if REST-interfaces are
> addressed
>   equally.
> 
> So, I guess the question would be: Is there a common (RDF-based)
> vocabulary
> (along with some standardised rules) available that would allow us to
> handle
> the above described setup on a generic, declarative level?
> 
> Any thoughts & pointers welcome!
> 
> Cheers,
> 	Michael
> 
> BTW: Please note that - in my understanding - the same might 
>      be applicable for resources (or repositories), and equally
>      one could extend it regarding QoS issues.
> 
> [1] http://www.w3.org/TR/2006/WD-swbp-vocab-pub-20060314/
> [2] http://www.w3.org/2007/powder/
> [3] http://www.w3.org/TR/2007/NOTE-powder-use-cases-20070525/
> [4] http://www.w3.org/2002/ws/policy/
> [5] http://www.w3.org/TR/2007/PR-ws-policy-20070706/
> 
> ----------------------------------------------------------
>  Michael Hausenblas, MSc.
>  Institute of Information Systems & Information Management
>  JOANNEUM RESEARCH Forschungsgesellschaft mbH
>  Steyrergasse 17, A-8010 Graz, AUSTRIA
> 
>  <office>
>     phone: +43-316-876-1193 (fax:-1191)   
>    e-mail: michael.hausenblas@joanneum.at
>       web: http://www.joanneum.at/iis/ 
> 
>  <private>
>    mobile: +43-660-7621761
>       web: http://www.sw-app.org/ 
> ----------------------------------------------------------
>

Received on Friday, 20 July 2007 10:47:20 UTC