Re: Proposal for Remote Procedure Call extensions to VISS.

>>  Or you introduce some “RPC” endpoints in the data model that expect
some complex input data and specifying return values. My feeling is that
the latter is too much.
I fully agree.

>> Maybe there is some middle ground, where one can define that there is an
RPC mechanism (which means, transports need to have a support  a generic
query/response scheme that can do more than “writeInt()->Done()”), but not
defining/modelling detailed RPC signaturess in VSS?

I think it is necessary to put proposals of this on the table to be able to
say yes or no to the question.
The JLR proposal is one, which has the advantage that it does not require
any modification of the standard (I believe?).

BR
Ulf


On Tue, Feb 11, 2020 at 10:26 AM Schildt Sebastian (CR/AEX1) <
Sebastian.Schildt@de.bosch.com> wrote:

> Hi,
>
>
>
> so I feel the main issue here  is one of scope for VISS:
>
>
>
> We definitely can have HTTP, “Classic”-Websocket, WAMP, MQTT, etc. as
> “transports”, and the VISS specification might just reference them as
> optional parts such as “IF you want to do REST with VISS ; HERE is how we
> suggest you do it, in case of WAMP map it like this, for MQTT….” A little
> bit like convergence layers in Bundle Protocol.
>
>
>
> But the question really is should the underlying data model understand the
> notion of RPCs? If an actor is just a node in the tree you can write to,
> and what will really happen is sort of hidden. Or you introduce some “RPC”
> endpoints in the data model that expect some complex input data and
> specifying return values. My feeling is that the latter is too much. (It
> might make VISS a feature monster….). Maybe there is some middle ground,
> where one can define that there is an RPC mechanism (which means,
> transports need to have a support  a generic query/response scheme that can
> do more than “writeInt()->Done()”), but not defining/modelling detailed RPC
> signaturess in VSS?
>
>
>
>
>
>
>
> Mit freundlichen Grüßen / Best regards
>
>
>
> *Sebastian Schildt CR/AEX1 *
> Tel. +49 711 811-15765 | Mobil +49 173 7124227
>
>
>
>
> * ► Take a look at Bosch Research: www.bosch.com/research
> <http://www.bosch.com/research> *
>
> *From:* Ulf Bjorkengren <ulfbjorkengren@geotab.com>
> *Sent:* Dienstag, 11. Februar 2020 09:36
> *To:* Magnus Feuer <mfeuer1@jaguarlandrover.com>
> *Cc:* public-automotive@w3.org
> *Subject:* Re: Proposal for Remote Procedure Call extensions to VISS.
>
>
>
> Thanks for the explanation.
>
>
>
> I see this as a rather lightweight wrapper on top of VISS(/Gen2) that
> provides a different interface style. Which is fine with me, but I am
> doubtful in it being a formal part of the standard.
>
> I also conclude that this is a different thing than WAMP that Gunnar
> mentioned.
>
>
>
> BR
>
> Ulf
>
>
>
> On Mon, Feb 10, 2020 at 11:03 PM Magnus Feuer <mfeuer1@jaguarlandrover.com>
> wrote:
>
> I forgot the most important bit, the function call itself:
>
>
>
> call_rpc("Vehicle.Cabin.Door.Row1.Left.Window.SetPosition", Position=50);
>
>
>
> The argument (Position) can either be defined locally in the RPC
> definition, as per my previous email, or be a reference / anchor to a
> signal (tree) living somewhere else in the spec
>
>
>
> /Magnus F.
>
>
>
> -------------------
>
> *System Architect Manager*
>
> *Jaguar Land Rover*
>
> *Email*: mfeuer1@jaguarlandrover.com
> *Mobile*: +1 949 294 7871
>
>
>
> [image: http://www.jaguarlandrover.com/email/jlr.jpg]
>
> Jaguar Land Rover North America, LLC
>
> 1450 NW 18th Ave, Portland, OR 97209
>
> -------------------
> Business Details:
> Jaguar Land Rover Limited
> Registered Office: Abbey Road, Whitley, Coventry CV3 4LF
>
> Registered in England No: 1672070
>
>
> This e-mail and any attachments contain confidential information for a
> specific individual and purpose.  The information is private and privileged
> and intended solely for the use of the individual to whom it is addressed.
> If you are not the intended recipient, please e-mail us immediately.  We
> apologise for any inconvenience caused but you are hereby notified that any
> disclosure, copying or distribution or the taking of any action in reliance
> on the information contained herein is strictly prohibited.
>
> This e-mail does not constitute an order for goods or services unless
> accompanied by an official purchase order.
>
>
> ------------------------------
>
> *From:* Magnus Feuer <mfeuer1@jaguarlandrover.com>
> *Sent:* Monday, February 10, 2020 13:52
> *To:* Ulf Bjorkengren <ulfbjorkengren@geotab.com>
> *Cc:* public-automotive@w3.org <public-automotive@w3.org>
> *Subject:* Re: Proposal for Remote Procedure Call extensions to VISS.
>
>
>
>
>
> Ulf,
>
>
>
> The idea is that the function name, and its arguments, live outside the
> VSS spec, driving our JLR principle of "RPC to actuate. Signal to sense".
> We are using a separate YAML file format for our service specifications.
>
>
>
> That said, the idea of integrating function names into the VSS spec is
> probably worth exploring, although it may be too much feature packing into
> a single spec.
>
>
>
> An RPC call in a VSS spec file would look something like:
>
>
>
> # Signal to report window position
>
> - Position:
>
>   datatype: uint8
>
>   type: sensor
>
>   min: 0
>
>   max: 100
>
>   unit: percent
>
>   description: Window position. 0 = Fully closed 100 = Fully opened.
>
>
>
>
>
> # RPC to actuate window position
>
> - SetPosition:
>
>   type: rpc
>
>   description: Move the window to a spcific position
>
>   arguments:
>
>     - TargetPosition:
>
>       datatype: uint8
>
>       min: 0
>
>       max: 100
>
>       unit: percent
>
>       description: The target position to move the window to. 0 = Fully
> closed 100 = Fully opened.
>
>   return:
>
>     - Result:
>
>       datatype: uint8
>
>       description: The result code (from a standard set of result codes)
>
>
>
>     - CurrentPosition:
>
>       datatype: uint8
>
>       min: 0
>
>       max: 100
>
>       unit: percent
>
>       description: The position of the window at the start of the window
> move
>
>
>
> Complex arguments (structs and nested structs) would look much like a
> signal tree.
>
>
>
> Thoughts?
>
>
>
> /Magnus F.
>
>
>
>
>
>
>
> -------------------
>
> *System Architect Manager*
>
> *Jaguar Land Rover*
>
> *Email*: mfeuer1@jaguarlandrover.com
> *Mobile*: +1 949 294 7871
>
>
>
> [image: http://www.jaguarlandrover.com/email/jlr.jpg]
>
> Jaguar Land Rover North America, LLC
>
> 1450 NW 18th Ave, Portland, OR 97209
>
> -------------------
> Business Details:
> Jaguar Land Rover Limited
> Registered Office: Abbey Road, Whitley, Coventry CV3 4LF
>
> Registered in England No: 1672070
>
>
> This e-mail and any attachments contain confidential information for a
> specific individual and purpose.  The information is private and privileged
> and intended solely for the use of the individual to whom it is addressed.
> If you are not the intended recipient, please e-mail us immediately.  We
> apologise for any inconvenience caused but you are hereby notified that any
> disclosure, copying or distribution or the taking of any action in reliance
> on the information contained herein is strictly prohibited.
>
> This e-mail does not constitute an order for goods or services unless
> accompanied by an official purchase order.
>
>
> ------------------------------
>
> *From:* Ulf Bjorkengren <ulfbjorkengren@geotab.com>
> *Sent:* Monday, February 10, 2020 02:20
> *To:* Magnus Feuer <mfeuer1@jaguarlandrover.com>
> *Cc:* public-automotive@w3.org <public-automotive@w3.org>
> *Subject:* Re: Proposal for Remote Procedure Call extensions to VISS.
>
>
>
> Hi,
>
>
>
> I think this could be an interesting extension to the standard.
>
> At the same time I see it as a "wrapper" on the standard, which I do not
> think should be part of the normative standard, possible a non-normative
> note or the like.
>
>
>
> I have a few comments on what is presented on
> https://github.com/PDXostc/viss-rpc.
>
> - In "subscribe" calls the path is explicitly used, while in "call" calls
> this is implicit in the "function" parameter (which must then by the
> receiving server be mapped to a path). This means every leaf node in the
> tree would have to have a unique function value.
>
> - In the "call" example the "arguments" filed contain the format of
> provided data. This format is known already by the server from the VSS
> metadata of this node. Providing it in the call open for the problem of
> mismatch with the metadata in the tree.
>
>
>
> I do not think that neither this nor WAMP, or any other pub-sub solution,
> should replace HTTP and/or WebSocket as transports, but rather complement
> them.
>
>
>
> BR
>
> Ulf
>
>
>
> On Fri, Feb 7, 2020 at 12:45 AM Magnus Feuer <mfeuer1@jaguarlandrover.com>
> wrote:
>
> All,
>
>
>
> We have been exploring an extended VISS protocol that allows for remote
> procedure calls to be invoked over the same websocket that today runs
> signal pub/sub.
>
> Since we believe this extension may be of use to the wider community, we
> would like to explore the possibility of expanding the W3C standard
> accordingly.
>
>
>
> The proposal, and a working sample implementation, can be found at:
>
>
>
> https://github.com/PDXostc/viss-rpc
>
>
>
> All is open sourced under MPLv2.
>
>
>
> This is in no way a completed spec. Things such as nested arguments
> (structs) and callbacks missing, so questions, proposals, and criticism
> would be much appreciated.
>
>
>
> If we come to an agreement that this is the right way forward I will make
> sure that JLR matures code and documentation as needed to integrate them
> into the W3C standard.
>
>
>
> Regards,
>
>
>
> /Magnus F.
>
>
>
> -------------------
>
> *System Architect Manager*
>
> *Jaguar Land Rover*
>
> *Email*: mfeuer1@jaguarlandrover.com
> *Mobile*: +1 949 294 7871
>
>
>
> [image: http://www.jaguarlandrover.com/email/jlr.jpg]
>
> Jaguar Land Rover North America, LLC
>
> 1450 NW 18th Ave, Portland, OR 97209
>
> -------------------
> Business Details:
> Jaguar Land Rover Limited
> Registered Office: Abbey Road, Whitley, Coventry CV3 4LF
>
> Registered in England No: 1672070
>
>
> This e-mail and any attachments contain confidential information for a
> specific individual and purpose.  The information is private and privileged
> and intended solely for the use of the individual to whom it is addressed.
> If you are not the intended recipient, please e-mail us immediately.  We
> apologise for any inconvenience caused but you are hereby notified that any
> disclosure, copying or distribution or the taking of any action in reliance
> on the information contained herein is strictly prohibited.
>
> This e-mail does not constitute an order for goods or services unless
> accompanied by an official purchase order.
>
>
>
>
>
>
> --
>
> *Ulf Bjorkengren*
>
> *Geotab*
>
> Senior Connectivity Strategist | Ph. D.
>
> Mobile
>
> +45 53562142
>
> Visit
>
> www.geotab.com
>
>
>
>
> --
>
> *Ulf Bjorkengren*
>
> *Geotab*
>
> Senior Connectivity Strategist | Ph. D.
>
> Mobile
>
> +45 53562142
>
> Visit
>
> www.geotab.com
>
>
>


-- 
Ulf Bjorkengren
*Geotab*
Senior Connectivity Strategist | Ph. D.
Mobile +45 53562142
Visit www.geotab.com