Yes. Although that symmetry might be functionally or high level in practice
than meaning the exact same interface/protocol. In my mind, it means both
use HTTP POST. ;)

On Mon, Jan 11, 2010 at 12:36 PM, Alexis Richardson <
[email protected]> wrote:

> Symmetric: means that the model for a subscriber being updated by a
> publisher is the same as the model for a publisher updating a
> subscriber.
>
>
> On Mon, Jan 11, 2010 at 8:31 PM, Ivan Žužak <[email protected]> wrote:
> > Not sure what "symmetric" implies exactly, but if it means that
> > publisher, subscriber and hub define roles, not components, and that a
> > component may implement multiple roles -- then that's what I have in
> > mind also. A component may thus, for example, both subscribe and be
> > subscribed to. So, yeah, this sounds like an option to be specified.
> >
> > Cheers,
> > Ivan
> >
> > On Mon, Jan 11, 2010 at 20:45, Alexis Richardson
> > <[email protected]> wrote:
> >> Ivan
> >>
> >> Thanks!  I am cc'ing Mike.
> >>
> >> I reckon that our contention is that being BOTH a (publishing) hub AND
> >> a subscriber requires treating the protocol as symmetric.
> >>
> >> This may require specifying, ideally as an option for PSHB.
> >>
> >> alexis
> >>
> >>
> >>
> >> On Mon, Jan 11, 2010 at 7:42 PM, Ivan Žužak <[email protected]> wrote:
> >>> Thanks Alexis! I responded to Mike on the blog. In short -- chaining
> >>> of hubs would not require changing the protocol, just the types of
> >>> components which implement parts of the protocol. Instead of having
> >>> just pure publishers, subscribers and hubs, there would be components
> >>> that implement multiple roles (e.g. a hub that supports chaining would
> >>> be both a hub and a subscriber). As Jeff said - this can all be broken
> >>> down to webhooks.
> >>>
> >>> Regular PSHB subscription would still work as before.
> >>> Publishing/filtering would just be an extension which a hub MAY
> >>> support. Of course, this requires some kind of fallback negotiation
> >>> for cases when a component doesn't support an extension requested by
> >>> another component.
> >>>
> >>> Ivan
> >>>
> >>> On Mon, Jan 11, 2010 at 19:21, Alexis Richardson
> >>> <[email protected]> wrote:
> >>>> Ivan, all,
> >>>>
> >>>> Mike Bridgen has elaborated on this in the comments to the post.
> >>>>
> >>>> I am copying his comments here:
> >>>>
> >>>> ---
> >>>>
> >>>> pubsubhubbub (0.1, anyway) doesn’t chain together in the way you’ve
> >>>> illustrated, because it’s not symmetrical — hubs don’t get subscribed
> >>>> to other hubs (or indeed, subscribe themselves). While you wouldn’t
> >>>> have to change the protocol, you would have to change the idea of what
> >>>> a hub is. But I guess you are setting out to do that anyway.
> >>>>
> >>>> For processing I can subscribe the remote processing service to the
> >>>> hub, and subscribe myself to the remote processor. Taking into account
> >>>> the verification, it would probably go
> >>>> 1. Me -> Remote: Please give me a token for this hub to post to you
> >>>> 2. Me -> Remote: Please subscribe me to you
> >>>> 3. Me -> Hub: Please subscribe Remote using this token
> >>>> This requires me and the remote processing service to understand some
> >>>> generalised bits of PSHB, but nothing extra of the hub (I don’t
> >>>> think).
> >>>>
> >>>> ---
> >>>>
> >>>> Cheers,
> >>>>
> >>>> alexis
> >>>>
> >>>>
> >>>>
> >>>> On Mon, Jan 11, 2010 at 5:21 PM, Alexis Richardson
> >>>> <[email protected]> wrote:
> >>>>> Ivan
> >>>>>
> >>>>> Possibly related to what Jeff says: how do you think hub-hub chaining
> works?
> >>>>>
> >>>>> Separately does PSHB subscription still work in your model?
> >>>>>
> >>>>> Great article btw.
> >>>>>
> >>>>> alexis
> >>>>>
> >>>>>
> >>>>> On Mon, Jan 11, 2010 at 5:14 PM, Jeff Lindsay <[email protected]>
> wrote:
> >>>>>> You should look into the greater webhooks ecosystem (slowly being
> called the
> >>>>>> Evented Web). It's all about the things your talking about here.
> >>>>>> http://webhooks.org
> >>>>>> Of particular interest might be Scriptlets (currently undergoing a
> major
> >>>>>> upgrade) and DrEval.
> >>>>>> -jeff
> >>>>>>
> >>>>>> On Mon, Jan 11, 2010 at 5:20 AM, Ivan Žužak <[email protected]>
> wrote:
> >>>>>>>
> >>>>>>> Hi all,
> >>>>>>>
> >>>>>>> Just wanted to point to my new blog post - http://bit.ly/5PMXGq.
> In
> >>>>>>> short, it's about extending PSHB to support not only real-time
> >>>>>>> delivery of feeds but also their filtering and processing via 3rd
> >>>>>>> party services. As I write in the post, I've discussed some of
> these
> >>>>>>> ideas a few months back with Julien (over email) and Brett (over
> >>>>>>> FriendFeed) but never got around to starting a broader discussion
> with
> >>>>>>> concrete ideas.
> >>>>>>>
> >>>>>>> Feedback is welcome and if it's mostly positive I think that would
> be
> >>>>>>> a good signal to start defining an extension to the protocol which
> >>>>>>> supports this.
> >>>>>>>
> >>>>>>> Thanks,
> >>>>>>> Ivan
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> --
> >>>>>> Jeff Lindsay
> >>>>>> http://webhooks.org -- Make the web more programmable
> >>>>>> http://shdh.org -- A party for hackers and thinkers
> >>>>>> http://tigdb.com -- Discover indie games
> >>>>>> http://progrium.com -- More interesting things
> >>>>>>
> >>>>>
> >>>>
> >>>
> >>
> >
>



-- 
Jeff Lindsay
http://webhooks.org -- Make the web more programmable
http://shdh.org -- A party for hackers and thinkers
http://tigdb.com -- Discover indie games
http://progrium.com -- More interesting things

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