Re: An opes usage question.

John,

	As far as I can see, your use case is 100% within the OPES
scope. However, you are probably thinking at the protocol level and,
hence, considering OCP protocol and not just OPES in general. If that
is the case, please read on.

	Your use case is a case of two application proxies using OCP
between each other: the data is pipelined via OCP from one application
hop to another, possibly with some other data returning to the first
hop. This use case has been discussed, but I do not think it was
explicitly documented.

	OCP protocol can be used to do what you want. You will need to
document and negotiate an OCP Core profile that specifies the details,
including sending trace data and billing information back to the first
proxy as an option. While doing that, you will need to be careful not
to be confused by terminology that targets classic "callout" rather
than classic "proxying" use cases.

	OCP protocol allows you to "pipeline" application messages
very efficiently. It has a few features targeted at classic "callout"
use cases, such as data preservation optimization. You will not
need/use those.

	You can take OCP Core and document an application profile that
changes OCP focus from callout to proxying. I cannot say whether OCP
is the best protocol for your needs since I do not know the details of
your environment. It may be a good candidate. Another option would be
to use the native/original application protocol in one direction and
return tracing/billing data via some other means.

	Please also see the following related message:
http://www.imc.org/ietf-openproxy/mail-archive/msg02830.html


	It would be great if you can contribute your use case (and
your OCP profile, if any) to OPES Framework. Please keep us posted on
your progress and do not hesitate to discuss any related issues on
this list.

Thanks,

Alex.


On Wed, 7 Jan 2004, John G. Waclawsky wrote:

> I have been looking over the opes drafts and trying to understand
> the efficiency of a distributed opes framework with a large volume
> of activity (and also trying to gauge how useful it would be for
> time dependent service execution activities). Consider an opes
> service where application data is transformed (or adapted) in some
> way. My question is, If I send the data flow to a callout server to
> perform some opes service task (or a string of call out servers),
> does the data always have to return to the data dispatcher at the
> opes data processor that directed the flow to the call out server in
> the first place (an ancillary question is: can just trace data and
> billing information only be sent back)?. Basically, will an opes
> framework allow the use of a piplining approach where once the
> service is complete at the call out server, the adapted application
> data can be forwarded directly to the data producer or data consumer
> (what ever the case may be)?  Any information, advice or council
> would be greatly appreciated. Thanks. Regards John