On Sun, Oct 25, 2009 at 1:08 AM, igrigorik <[email protected]> wrote:

>
> This doesn't answer roster management, but an OPML export from the hub
> of all the available feeds would certainly work for me.
>
> @Nick: Does the hub really need to have a subscriber? If as a
> publisher I register my feed with the hub it could still keep it in
> the roster -- the hub just doesn't have to do anything if there are no
> subscribers, just discard the pings. Although, if there was a firehose
> delivery mechanism, then you could implicitly call that a subscriber
> to every feed.
>

It could - but the reference implementation, at least, ignores publisher
pings for feeds with no subscribers. I don't have hard numbers, but I
suspect doing this eliminates a significant chunk of redundant work.

-Nick Johnson


>
> ig
>
> On Oct 22, 9:37 am, Alexis Richardson <[email protected]>
> wrote:
> > I don't think that's crazy at all.  I suppose the question would then
> > become how to make this 'standard' for roster discovery and
> > management.
> >
> > On Thu, Oct 22, 2009 at 2:22 PM, igrigorik <[email protected]> wrote:
> >
> > > Ok, so let me try rephrasing the problem. The major problem is not the
> > > Hub, or the spec, but the need to crawl thousands of sites to find the
> > > feeds in the first place. Of course, the hub already knows about them,
> > > hence this discussion.
> >
> > > Would it be crazy to then expose a mechanism to enumerate all of the
> > > feeds that a hub tracks, and let the client then subscribe to them?
> >
> > > An obvious obstacle is private feeds, but I wonder if that can be
> > > handled as a special case?
> >
> > > ig
> >
> > > On Oct 21, 1:55 pm, Marcus Herou <[email protected]> wrote:
> > >> Well... We can as well publish a firehose but currently our business
> > >> model is not aimed at that.
> >
> > >> I was not talking about a service rather a technology which could take
> > >> the crawling business to another level by aggregating hundreds of hubs
> > >> and creating something which effectively can deliver tb/s bandwidth by
> > >> having decentralized servers and data. We are still limited you know
> > >> by our infrastructure even though it have gb/s to the internet.
> >
> > >> Since the realtime web is currently still very small all of us need to
> > >> poll something even you I presume to be able to create a pub/sub arch.
> > >> In that remark our companies are quite similar, you chose to aggregate
> > >> and publish your data and make a business of it. We aggregate and
> > >> refine the data and make business out of that.
> >
> > >> Dont take me wrong I really like what you do but i am not looking for
> > >> a data supplier at this time ( might change though ). But if I would
> > >> look in the data supplier direction you are currently in my/our top
> > >> ten list :)
> >
> > >> Skickat från min iPhone
> >
> > >> On Oct 21, 5:03 pm, Julien Genestoux <[email protected]>
> > >> wrote:
> >
> > >> > Hum...http://superfeedr.com?
> >
> > >> > "Putting ressources in common" is definetely one of the key reasons
> why we
> > >> > built superfeedr. More about that there :
> http://blog.superfeedr.com/gospel/something-stupid/
> >
> > >> > And yes, we have a firehose available.
> >
> > >> > Julien
> >
> > >> > --
> > >> > Julien Genestoux,
> >
> > >> >http://twitter.com/julien51http://superfeedr.com
> >
> > >> > +1 (415) 254 7340
> > >> > +33 (0)9 70 44 76 29
> >
> > >> > On Wed, Oct 21, 2009 at 5:26 AM, Marcus Herou <
> [email protected]>wrote:
> >
> > >> > > Feedtree looks cool.... but updated 2006 ?
> >
> > >> > > On Wed, Oct 21, 2009 at 2:20 PM, Nick Johnson (Google) <
> > >> > > [email protected]> wrote:
> >
> > >> > >> On Wed, Oct 21, 2009 at 1:14 PM, Alexis Richardson <
> > >> > >> [email protected]> wrote:
> >
> > >> > >>> Hmmm ... gossiptorrent?
> >
> > >> > >> Feedtree.
> >
> > >> > >>> On Wed, Oct 21, 2009 at 7:23 AM, Marcus Herou
> > >> > >>> <[email protected]> wrote:
> >
> > >> > >>> > Hi.
> >
> > >> > >>> > We host a search app which is based on feeds of
> blogs/twitter/forums/
> > >> > >>> > news etc. We are as you are mentioning polling everything like
> crazy
> > >> > >>> > and it seems like a total waste of everyones resources.
> >
> > >> > >>> > So this means that subscribing to something which would
> potentially
> > >> > >>> > deliver the material to us would be great not just for us but
> as well
> > >> > >>> > all sites we are crawling.
> >
> > >> > >>> > However who would like to open up a firehose for free for
> everyone to
> > >> > >>> > consume ? It will for sure consume a lot of bandwidth and a
> few
> > >> > >>> > subscribers will consume most of the bandwidth with this
> model.
> > >> > >>> > I thought of something that might solve this issue. Consider
> the
> > >> > >>> > following:
> >
> > >> > >>> > 1)
> > >> > >>> > * Charge for the bandwidth (wordpress.com does this with flat
> fee)
> >
> > >> > >>> > 2)
> > >> > >>> > * Everyone that have firehose consuming needs should as well
> start a
> > >> > >>> > hub to show good faith and morale.
> > >> > >>> > * Add support in firehose enabled hubs to share state (with a
> > >> > >>> > master ?)
> > >> > >>> > * A firehose enabled hub can subscribe to a master hub which
> makes
> > >> > >>> > sure that the subscriber as well fulfils some form of contract
> (i.e.
> > >> > >>> > actually updating/delivering feeds)
> > >> > >>> > * Each firehose enabled hub must be public and everyone can
> subscribe
> > >> > >>> > to the feeds like as of current.
> > >> > >>> > * To share load equally (morale part) then subscribers should
> > >> > >>> > subscribe to a loadbalanced dns name or some form of delegate
> > >> > >>> >  lb.pshb.com = master hub
> > >> > >>> >  Example 1: lb.pshb.com resolves to pshb.tailsweep.com
> > >> > >>> > pshb.google.com, effectively DNS-roundrobin
> > >> > >>> >  Example 2: lb.pshb.com delegates to any active master
> connected hub
> > >> > >>> > in some way.
> >
> > >> > >>> > This might be too complex to implement and bottlenecks occur
> at the
> > >> > >>> > master but systems like Hadoop have bottlenecks in terms of
> the
> > >> > >>> > NameNode (master) and it seems to perform just perfect so it
> can be
> > >> > >>> > done. However each firehose hub probably need to persist each
> feed for
> > >> > >>> > a certain amount of time before purging it.
> >
> > >> > >>> > Anyway this was just a thought. We at Tailsweep probably could
> help in
> > >> > >>> > making this happen if there exists some interest.
> >
> > >> > >>> > Cheers
> >
> > >> > >>> > //Marcus
> >
> > >> > >>> > On Oct 20, 8:41 pm, Bob Wyman <[email protected]> wrote:
> > >> > >>> >> On Tue, Oct 20, 2009 at 11:22 AM, igrigorik <
> [email protected]> wrote:
> > >> > >>> >> > Specifically, if we treat 'firehose' as any bundle of
> > >> > >>> >> > feeds (all, or some), then a hub could define
> > >> > >>> >> > multiple firehose streams.
> >
> > >> > >>> >> There should be no question that there is tremendous utility
> in being
> > >> > >>> able
> > >> > >>> >> to compose all sorts of "bundles" of topics into distinct
> feeds. It is
> > >> > >>> >> probably also the case that we can identify some number of
> such
> > >> > >>> bundles that
> > >> > >>> >> would be useful to a large number of subscribers. On the
> other hand,
> > >> > >>> many
> > >> > >>> >> bundles will be very specific and only useful to one or a
> small number
> > >> > >>> of
> > >> > >>> >> subscribers. In fact, I think what we'll see is that once we
> have the
> > >> > >>> core
> > >> > >>> >> PSHB defined, we'll then see innovation in the definition of
> "down
> > >> > >>> stream"
> > >> > >>> >> services whose function is precisely to build and deliver
> such
> > >> > >>> bundles. Some
> > >> > >>> >> of these services will aggregate groups of topics while
> others will
> > >> > >>> focus
> > >> > >>> >> instead on creating content-based streams -- they will bundle
> together
> > >> > >>> >> individual entries based on the content of those entries
> rather than
> > >> > >>> simply
> > >> > >>> >> combining all entries from some set of topics.
> >
> > >> > >>> >> I think we should be careful not to force too much of the
> burden of
> > >> > >>> bundling
> > >> > >>> >> or aggregating into the core PSHB hub specification. If we
> want to
> > >> > >>> address
> > >> > >>> >> the challenges of building bundles or aggregations, I think
> it best to
> > >> > >>> do so
> > >> > >>> >> in secondary or companion specifications. This will keep the
> core
> > >> > >>> cleaner
> > >> > >>> >> and easy to understand while also allowing the core to be
> deployed
> > >> > >>> without
> > >> > >>> >> being delayed by discussions over non-core issues.
> >
> > >> > >>> >> Having argued against making the core more complicated by
> extending it
> > >> > >>> to
> > >> > >>> >> include creating aggregate topics, I still suggest that it
> would be
> > >> > >>> useful
> > >> > >>> >> to have the core system define a common means to obtain a
> pure
> > >> > >>> "firehose"
> > >> > >>> >> feed of all topics. The current hub spec works for people who
> only
> > >> > >>> want
> > >> > >>> >> "none or some" of the topics served by the hub. I suggest
> that we
> > >> > >>> expand
> > >> > >>> >> this to have hubs know how to provide "none, some or all" of
> the
> > >> > >>> topics.
> > >> > >>> >> The reason for adding support of "all topics" is that we
> know, without
> > >> > >>> much
> > >> > >>> >> question, that such an "all topics" feed will be required by
> many of
> > >> > >>> the
> > >> > >>> >> downstream services that we will one day be relying on to
> create more
> > >> > >>> finely
> > >> > >>> >> defined aggregations. Given that this specific feed will be
> commonly
> > >> > >>> >> required, it would be best if we had a common mechanism for a
> > >> > >>> downstream
> > >> > >>> >> service/subscriber to request that feed and that we set some
> > >> > >>> expectations
> > >> > >>> >> for how that feed will be formatted and delivered (i.e. Atom
> entries,
> > >> > >>> >> persistent connections, chunked content model, ...). It would
> be very
> > >> > >>> >> cumbersome for a downstream filtering/aggregating service to
> need to
> > >> > >>> puzzle
> > >> > >>> >> through service specific mechanisms for discovering how to
> obtain a
> > >> > >>> firehose
> > >> > >>> >> feed of "all topics" from many different hubs.
> >
> > >> > >>> >> bob wyman
> >
> > >> > >>> >> On Tue, Oct 20, 2009 at 11:22 AM, igrigorik <
> [email protected]> wrote:
> >
> > >> > >>> >> > Right, so how does the smart hub aggregate the feeds? Does
> it then
> > >> > >>> >> > have to crawl to find the list? That wouldn't be very
> useful. Having
> > >> > >>> >> > said that...
> >
> > >> > >>> >> > +1 For 'smart, aggregating hub generating a synthetic feed'
> > >> > >>> >> > +1 For XRD discovery of the firehose endpoint.
> >
> > >> > >>> >> > Thinking a bit more about the firehose, what about making
> it more
> > >> > >>> >> > flexible. Specifically, if we treat 'firehose' as any
> bundle of
> > >> > >>> feeds
> > >> > >>> >> > (all, or some), then a hub could define multiple firehose
> streams.
> > >> > >>> For
> > >> > >>> >> > example, at PostRank we classify feeds by topic, so if
> someone
> > >> > >>> wanted
> > >> > >>> >> > to subscribe to "Technology", we could expose that as a
> firehose so
> > >> > >>> >> > the user doesn't have to subscribe to every feed in that
> topic. In
> > >> > >>> >> > essence, a firehose stream is then any bundle of feeds.
> >
> > >> > >>> >> > This may be overloading the hub spec but the overall
> mechanics would
> > >> > >>> >> > be:
> > >> > >>> >> >  - A (super)user can declare a
> >
> > ...
> >
> > read more »
>



-- 
Nick Johnson, Developer Programs Engineer, App Engine
Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number:
368047

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