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
>>>>>>
>>>>>
>>>>
>>>
>>
>

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