Michael,
I like that way that you put it. Hopefully what we wind up with is a
protocol that is fundamentally P2P but which interacts with servers as
ultra-efficient UI-less peers equipped with some super-powers and services
that may not be present in the P2P domain persistently. Call it p2p2P, so
to speak. John
On Fri, Jun 21, 2013 at 10:04 PM, Michael MacFadden <
michael.macfad...@gmail.com> wrote:
> MY humble opinion on the P2P issue is as follows. I think if we develop
> algorithms that can work in a P2P mode, then we can also support a
> client/server architecture as well by just controlling who the peers talk
> to. I think the problem with wave was not the client server architecture,
> but rather the way the servers interacted with each other. The servers
> themselves implemented something like a client/server relationship within
> federation. This meant that even if you were connected to your local wave
> server, if that wave server could not communicate with the wave server
> that initiated the wave, you were out of luck.
>
> I am not against having servers at all. In fact I think that things get
> very complicated if you have no servers what so ever (document storage,
> discovery, users, etc.). But if we need to make sure servers are peers.
> So we need a P2P style OT algorithm. Again do not confuse a P2P network
> topology (DHT, etc) with P2P OT Algorithms. A P2P OT Algorithm can also
> easily be made to behave like a Client/Server OT algorithm, where as the
> reverse is not feasible.
>
> ~Michael
>
> On 6/21/13 5:46 PM, "Sam Nelson" <so...@orcon.net.nz> wrote:
>
> >Wow, that was some heavy reading (:
> >
> >This section raised some questions for me:
> >
> >*4) Routing p2p messages/events in a pure P2P system (5 parts)*
> >How to manage to route all wave-stuff if we want to completely get rid of
> >servers completely, and only use peers.
> >The closest way would be to use a DHT, but huge latency is an unsolved
> >problem, and makes it impossible to use for real-time waving.
> >No other solution has been proposed.
> >
> >My question is simply, perhaps naively: why pure p2p?
> >Originally when I heard of p2p OT I saw it as a way to collaboratively
> >work offline in a LAN environment, and to sync pairs that are almost
> >always offline, by means of a proxy peer that moves between WAN and the
> >offline LAN. The peers would talk in much the same way that two
> >federating servers would, using their offline caches as a datasource
> >instead I'm guessingthis is like the MESH network John refers to.
> >
> >When talking about P2P between peers /over the internet/ - could
> >somebody please explain to be the purpose of and vision for this? Why
> >not just use a server, it seems to simplify things alot? (Firewalls,
> >authentication - can do offline like Windows 8 does with Microsoft
> >Account)
> >
> >Is purep2p just for privacy? Or is it really for alternate uses of the
> >protocol - other than the the documents and conversation use cases we
> >saw in Google Wave?
> >
> >Just an idea, in order to "open the eyes" of those drawn to this mailing
> >list, might it be beneficial to build up a wiki page of accepted use
> >cases so that everyone can read them and take them into account when
> >considering different ideas? That'd facilitate discussions like "well
> >this works for all our use cases except #13.... <discussion ensues about
> >this case>"
> >
> >Sam
> >
> >
> >On 22/06/2013 01:06, John Blossom wrote:
> >> Bruno,
> >>
> >> Thanks, this is an excellent summary. It helps me to get the gist of
> >>things
> >> more clearly.
> >>
> >> On the P2P latency, I don't think that it would be unacceptable to draw
> >>a
> >> line and say that P2P provides limited, non-guaranteed realtime OT or
> >>that
> >> it's not realtime OT and more of a syncing mode than a conversation
> >>mode.
> >> That would probably be sufficient for what needs to be done, especially
> >> since in some instances P2P-enabled Wave sessions may be using MESH
> >> networks for transport - a key factor in how a lot of experimental
> >> communications services are being deployed in developing nations (not
> >>just
> >> the Project Loon concept). In the MESH model, you're likely to have one
> >> node within range of another temporarily, which may sync with it, and
> >>then
> >> pass along data to another node when it comes in range of it. That's the
> >> most probable scenario for P2P in many instances, I would think. The
> >>other
> >> potential scenario: two people in a remote location, for the sake of
> >> argument two movie script-writers who have holed themselves up in a
> >>remote
> >> location to collaborate on a common script. They're on two devices that
> >>are
> >> very proximate to one another, so perhaps the latency issues will not
> >>be so
> >> severe.
> >>
> >> Things to think about, I will look at this more carefully later today.
> >>
> >> All the best,
> >>
> >> John Blossom
> >>
> >> On Fri, Jun 21, 2013 at 8:05 AM, Bruno Gonzalez (aka stenyak) <
> >> sten...@gmail.com> wrote:
> >>
> >>> Following Joseph's "A Very Wavey Plan (P2P!)" thread, a couple of
> >>> discussions have taken place at the irc.freenode.net #wiab channel,
> all
> >>> related to P2P.
> >>>
> >>> I've taken the liberty to restructure the IRC logs, remove some
> >>>chitchat,
> >>> and divide it into sub-discussions. Feel free to reply to any part of
> >>>this
> >>> email to continue a discussion.
> >>>
> >>>
> >>> *Summary of discussions:*
> >>> *====================*
> >>> *1) Underlying protocol for P2P federation*
> >>> Currently XMPP is used. HTTP and raw TCP are two suggested candidates
> >>>(HTTP
> >>> allowing to much more easily reach restricted networks).
> >>>
> >>> *2) Message/event types needed for P2P federation to work*
> >>> We'd need something similar in concept to certain git operations (git
> >>> clone, git push...). All will be based on hashes (not incremental
> >>> integers).
> >>>
> >>> *3) Routing p2p messages/events in a server-aided network*
> >>> One option is to somehow detect server clusters, send data to one of
> >>>them,
> >>> and let the rest of the cluster servers synchronize to it (locally).
> >>> Alternatively, the originator server can naively send stuff to all
> >>>possible
> >>> destination servers, regardless of the cost.
> >>>
> >>> *4) Routing p2p messages/events in a pure P2P system (5 parts)*
> >>> How to manage to route all wave-stuff if we want to completely get rid
> >>>of
> >>> servers completely, and only use peers.
> >>> The closest way would be to use a DHT, but huge latency is an unsolved
> >>> problem, and makes it impossible to use for real-time waving.
> >>> No other solution has been proposed.
> >>>
> >>> *5) Implementing "undo": invertibility, tombstones, edge cases, TP2*
> >>> No server means no canonical order of commits, which means that undo is
> >>> hard to do correctly.
> >>> (uhm... not sure if that's a good summary, some stuff went over my head
> >>> :-D, please read the log instead)
> >>>
> >>> *6) Usability of a pure p2p system in Real Life (tm)*
> >>> Being pragmatic, pure P2P is probably only usable in peers with good
> >>> connectivity. Rest of peers will need to rely on a server/proxy that
> >>>*does*
> >>> have good connectivity.
> >>>
> >>> *7) Comparison with BitTorrent and P2P-TV technologies*
> >>> Both technologies are much less restricted than wave with regards to
> >>> real-time responsiveness. So none are really a good reference for our
> >>> purposes.
> >>>
> >>> *8) Identifying participants (3 parts)*
> >>> Pure p2p means many peers don't have a name@centralized-server.comuser
> >>> handle, so an alternative has to be used.
> >>> However, it's easy to provide a traditional friendly handle, if the
> >>>user
> >>> prefers the tradeoff of having to often rely on a permanent server.
> >>>This
> >>> tradeoff can be mitigated by using a sort of userhandle cache.
> >>>
> >>> *9) P2P anonymity (lurking in a wave) (2 parts)*
> >>> In a pure p2p wave network, anonymous peers may want to read a public
> >>>wave,
> >>> without other peers knowing. A solution could be to make private the
> >>> required wavelets (where the anonymous participants IDs are stored).
> >>>
> >>> *10) Encryption of waves*
> >>> It's been proposed to use an AES key to encrypt all the wave data, and
> >>>only
> >>> allow participants to decrypt it.
> >>>
> >>> *11) Addition and removal of participants, and their ability to read
> >>>past
> >>> and future wave versions/deltas*
> >>> The aforementioned AES key can change over time, allowing a
> >>>finer-grained
> >>> restriction of what deltas new/removed participants can read.
> >>>
> >>>
> >>> *
> >>> *
> >>>
> >>> *Actual conversations:*
> >>> *====================*
> >>> *
> >>> *
> >>> *1) Underlying protocol for P2P federation:*
> >>> [in response to Joseph's email]
> >>> [23:42] <alown> I [...] agree with option 2 (make every root a JSON
> >>>blob)
> >>> [23:43] <alown> You haven't really detailed (at all) how the P2P
> >>>federation
> >>> is actually going to work (beyond 'not like IRC')
> >>> [23:44] <josephg> Personally, I'd love some raw TCP action
> >>> [23:44] <alown> I agree using KISS principle.
> >>> [23:44] <josephg> a few years ago (not long after wave was cancelled)
> >>>there
> >>> was a 'wave summit'
> >>> [23:45] <josephg> - and a few of us chatted about how we could make the
> >>> federation protocol simpler
> >>> [23:45] <josephg> we ended up (somehow) deciding that doing it over
> >>>http
> >>> woul dbe a good idea
> >>> [23:45] <josephg> because then we could sneak it into companies past
> >>>their
> >>> corporate HTTP firewalls, etc
> >>> [23:45] <josephg> but in any case, I'd like to figure out the protocol
> >>>and
> >>> (at least) have a TCP version
> >>> [23:46] <josephg> it should be pretty easy to wrap the same messages in
> >>> websockets if we want
> >>>
> >>>
> >>> *2) **Message/event types needed for P2P federation to work:*
> >>> [23:46] <alown> Do we need anything more complicated than the
> >>> waveletSubmit/Commit messages used currently?
> >>> [23:46] <alown> (Replace wavelet with 'abstract p2p ot container name)
> >>> [23:46] <josephg> um, yeah.
> >>> [23:47] <josephg> we'll also be able to rip out all the code that deals
> >>> with managing the tree of servers per wave
> >>> [23:47] <josephg> but yeah - the protocol will get a bit more
> >>>complicated
> >>> [23:47] <josephg> ... because we'll lose our beautiful integer version
> >>> numbers
> >>> [23:47] <josephg> so we'll need a protocol for syncronizing ops
> >>> [23:48] <josephg> yeah - ops will each have a hash
> >>> [23:48] <josephg> and two servers could each have ops the other server
> >>> doesn't have
> >>> [23:48] <josephg> so we have to be able to deal with that
> >>> [23:47] <alown> What other 'events' are cared about by any particular
> >>> server?
> >>> [23:47] <alown> For a SHA hash?
> >>> [23:48] <josephg> -> we'll need something like git's sync protocol
> >>> [23:48] <alown> So, initial server contact is 'git clone', and then
> >>>some
> >>> form of 'git push' on changes?
> >>> [23:49] <josephg> yep.
> >>> [23:49] <josephg> push on changes is easy - its basically the same
> >>>thing we
> >>> have now
> >>> [23:49] <josephg> just instead of saying "This should be applied at
> >>>version
> >>> 10" we say "This op has parents [abc123, def456]"
> >>>
> >>>
> >>> *3) **Routing **p2p **messages/events in a server-aided network:*
> >>> [23:49] <alown> With P2P do we have to broadcast to all peers? How do
> >>>we
> >>> coordinate that between them?
> >>> [23:50] <josephg> between servers? I dunno.
> >>> [23:50] <alown> How does BT handle this?
> >>> [23:50] <josephg> should we just connect every server to every other
> >>> server? That'd work fine...
> >>> [23:50] <josephg> I guess every server can address every other server
> >>> [23:50] <josephg> beacuse the wave will have al...@a.com and
> >>> josephg@b.comand so on on it
> >>> [23:50] <alown> This feels very inefficent...
> >>> [23:51] <josephg> so if you submit an op to your server, your server
> >>>can go
> >>> "Oh, I need to tell b.com about this too"
> >>> [23:51] <josephg> well, if there's 10 servers, presumably all 10
> >>>servers
> >>> need to find out about ops somehow.
> >>> [23:51] <josephg> - assuming we stick with the current model of having
> >>> servers store all your operations
> >>> [23:51] <josephg> .. and documents for all the users at their domain
> >>> [23:51] <alown> But server 'b' and 'c' might both be part of a wave,
> >>>but
> >>> also know each other, and know that they are 'closer' to each other
> >>>than
> >>> 'a' is. So, we would want a->b/c then b<->c
> >>> [23:52] <josephg> so actually, having the server which originates an
> >>> operation send it to all the other servers on that wave is actually
> >>>close
> >>> to ideal.
> >>> [23:52] <josephg> yeah maybe.
> >>>
> >>>
> >>> *4) **Routing **p2p **messages/events in a pure P2P system (part 1):*
> >>> [23:54] <alown> BT uses DHT for its P2P stuff...
> >>> [23:54] <josephg> ...I guess we could use a DHT storing all the ops,
> >>>but
> >>> thats pretty slow
> >>> [23:55] <josephg> and you still need to notify all servers with users
> >>>on
> >>> the wave that the wave was updated.
> >>> [23:55] <alown> Maybe, or perhaps only notify those within a certain
> >>> 'distance', with each server doing that. (Though could mean some
> >>>servers
> >>> are never updated)
> >>> [23:58] <alown> Perhaps we could make the network setup 'SuperWaves'
> >>>which
> >>> broadcast to all peers, and carry all information, but normal wave
> >>>servers
> >>> do not reach this status?
> >>> [23:58] <alown> By having it decide itself based on how 'connected' a
> >>> server is, this could find the most efficent ways to route it.
> >>> [00:01] <josephg> Do you think it'll really be a problem?
> >>> [00:01] <josephg> I mean, thinking about it - how many servers will be
> >>>on a
> >>> given wave?
> >>> [00:01] <alown> Depends.
> >>> [00:01] <alown> No idea.
> >>> [00:01] <josephg> If it were a public wave, I can imagine clients just
> >>> connecting to one (or more) centralized servers
> >>> [00:01] * josephg nods
> >>> [00:02] <josephg> ... But say if we were having a conversation on
> >>> wave-dev@apache, there's like, at most 20 people in a discussion from
> >>>5 or
> >>> so domains
> >>> [00:03] <josephg> ... I think we can deal with that kind of load.
> >>> [00:04] <josephg> but if the protocol lets any server tell any other
> >>>server
> >>> about an operation, then it should be pretty easy to set up something
> >>>like
> >>> that.
> >>> [00:04] <josephg> maybe.
> >>> [00:04] * josephg thinks
> >>> [00:05] <josephg> hm - you're right. I think I've just gotten used to
> >>>the
> >>> crappy state of doing routing for broadcasting messages to a network
> >>> [00:05] <josephg> if you can find / think of a better solution, I'm in.
> >>> [00:12] <alown> Heh, anyway replacing the network layer code SHOULD be
> >>> easy, since it SHOULD be cleanly seperated.
> >>> [00:13] <alown> Getting an initial implementation up using broadcast is
> >>> fine.
> >>> [00:13] <alown> (I was thinking of Wave's use in other apps as a
> >>>reason you
> >>> could have a lot of different participant domains)
> >>> *...4) Routing **p2p **messages/events in a pure P2P system (part 2):*
> >>> [08:53] <stenyak> as for the "how to *really* do p2p", i see two
> >>>options:
> >>> a) use a dht-like algorithm and/or b) use a helper server to route
> >>>stuff
> >>> for you
> >>> [08:54] <stenyak> a) can be pretty slow if you want all OPs to reach
> >>>all
> >>> peers (if I'm not mistaken)
> >>> [08:54] <stenyak> and b) is essentially makes it not-p2p
> >>> [08:55] <stenyak> additionally, using p2p, how are we going to deal
> >>>with
> >>> routing problems (such as firewalls on both sides, etc)?
> >>> [08:56] <stenyak> in my mind, the only universal solution is to have a
> >>> third party server available to go through if we want speed or if we
> >>>want
> >>> to work on all edge cases
> >>> [08:56] <stenyak> and wave being advertised as realtime, i don't see
> >>>how
> >>> something like dht can ever fly
> >>> [11:20] <alown> stenyak: This is why I was wondering about a DHT system
> >>> with 'Superwave' servers (to act as a first point of contact).
> >>> [11:59] <stenyak> that would be like skype dynamic supernode list?
> >>> [11:59] <alown> The original system, yes.
> >>> [12:02] <stenyak> so we would devise a method to identify candidates to
> >>> being a supernode, in order to prevent cellphone wave peers from
> >>>becoming
> >>> one, and in order to promot certain other nodes (like major peers that
> >>>have
> >>> 99% uptime, e.g. wave.google.com or whatever) to become one
> >>> [12:03] <stenyak> bandwidth, latency, open ports, uptime...
> >>> [12:04] <alown> Once a network has been bootstrapped using something,
> >>>it is
> >>> relatively easy to identify the hosts which are most densely connected
> >>>(and
> >>> would be good supernode candidates)
> >>> [12:05] <stenyak> what do you mean with "using something"?
> >>> [12:06] <alown> Somehow the network has to initially be able to make
> >>> contact with other nodes (before it knows anything about them)
> >>> [12:07] <alown> For a LAN you could get away with a broadcast
> >>>'announce',
> >>> but it is a bit less clear on an internet-sized scale.
> >>> [12:08] <stenyak> bittorrent sync uses a broadcast for LAN. for
> >>>internet it
> >>> uses a tracker server for fast discovery of peers, or you can disable
> >>>that
> >>> and force to use DHT (with the long wait that means)
> >>> [12:09] <stenyak> the tracker can also act as a meeting-point for
> >>> firewalled peer pairs (which in my experience is a lot of them)
> >>> [12:09] <alown> Precisely the problem, because we don't really want
> >>>long
> >>> waits or trackers.
> >>> *...4) Routing **p2p **messages/events in a pure P2P system (part 3):*
> >>> [12:42] <stenyak> hmmm... i'm not sure how a peer gets a list of waves
> >>>in
> >>> which he's a participant of
> >>> [12:43] <alown> Having a canonical source makes it all so much easier.
> >>>:P
> >>> [12:44] <stenyak> for pure p2p peers to "receive" new waves, either the
> >>> FROM or the TO peer (or both) would need to try to find their way to
> >>>the
> >>> other
> >>> [12:44] <stenyak> and we're assumign here that each person only runs
> >>>one
> >>> peer
> >>> [12:45] <stenyak> e.g. my privatekey may be used by 5 wave peers at the
> >>> same time, and we must make sure the new wave reaches all of them
> >>> [12:46] <alown> Looks like we may need to have mulitple DHTs then (one
> >>>for
> >>> ops, one for waves)
> >>> [12:46] <stenyak> in BT, it's the receiver end who actively looks for
> >>>peers
> >>> to receive from. in wave, it's not like that..
> >>> [12:46] <alown> Or could we have a pubkey->wave mapping in one?
> >>> [12:46] <stenyak> and in BT, you can assume *many* people has the data
> >>>you
> >>> want
> >>> [12:46] <stenyak> in wave, its possible and probably that only one
> >>>other
> >>> peer in the universe has the wave
> >>> [12:46] <stenyak> (because it's a personal wave sent to you)
> >>> [12:47] <alown> I would expect any long-running supernodes to be
> >>>implicitly
> >>> part of all waves they know about.
> >>> [12:47] <alown> Though on second thought, this seems like it would add
> >>>its
> >>> own problems to authentication, storage, promotion of supernodes etc.
> >>> *...4) Routing **p2p **messages/events in a pure P2P system (part 4):*
> >>> [12:51] <alown> Does it make sense for a peer to have your privkey,
> >>>since
> >>> you could be logged in anywhere, so it would be down to the place you
> >>>are
> >>> logged in, to 'subscribe' to that wave on the network, and attempt to
> >>> retrieve all data from it...
> >>> [12:55] <alown> I was expecting the network as a whole to act like a
> >>> WaveBus pubsub system, whereby once 'logged in' at some server (which
> >>>means
> >>> it gets your privkey from the authentication system), that server then
> >>> 'subscribes' to your waves on the 'network'. If somebody else at some
> >>>other
> >>> server changes it, then that server would be announcing to the network
> >>>of a
> >>> change (doesn't necesserily have to be a broadcast), which your server
> >>> would 'hear'.
> >>> [12:56] <alown> You could do this from any server where you logged in
> >>> (hence the concept of a domain is lost).
> >>> [12:57] <stenyak> by "server" you mean supernodes?
> >>> [12:57] <alown> Not necessarily.
> >>> [12:59] <stenyak> this pubsub network must be aware of nodes that are
> >>>in
> >>> it, in order to directly route wave updates to them, correct?
> >>> [12:59] <stenyak> and also, this network wouldn't be very volatile, but
> >>> would rather ideally be long-lived peers?
> >>> [13:00] <alown> It has no reason to have to directly route updates,
> >>>(though
> >>> it would hopefully be able to identify the best routes automatically).
> >>> [13:00] <alown> Yes it would require a few long-lived peers (which
> >>>would be
> >>> part of the requirement to be a supernode).
> >>> [13:01] <stenyak> so let's say i connect my laptop wave peer to the
> >>> "server" in the living room, at my firewalled home. this "server"
> >>>would be
> >>> already subscribed to the pubsub network, and in this specific case it
> >>> would route all wave updates to me
> >>> [13:02] <stenyak> in other cases (let's say, ipv6-enabled nodes
> >>>everywhere,
> >>> no firewall at home), the living room server could simply notify the
> >>> original "FROM" peer to send stuff to my laptop ipv6 ip, right?
> >>> [13:03] <alown> That sounds right. Supernodes are really only needed
> >>>for
> >>> getting the routing right.
> >>> [13:05] <stenyak> ok. in both these theoretical cases, the "server"
> >>>hasn't
> >>> necessarily been a wave node per se (nor a supernode either), but
> >>>rather a
> >>> second type of wave node that helps get stuff quickly wherever it's
> >>>needed
> >>> [13:05] <alown> Yes.
> >>> [13:05] <alown> I am not even sure where OT should be happening in this
> >>> picture...
> >>> [13:05] <stenyak> if OT happens, the "server" is a blind proxy i think
> >>> [13:06] <stenyak> so does not need the privkey to work
> >>> [13:07] <stenyak> unless we're also using OT in the wavebus pubusb
> >>>network
> >>> for some reason?
> >>> [13:07] <alown> Supernodes can be blind (though they might also just be
> >>> normal well-connected wave servers). I would expect normal servers to
> >>>still
> >>> be doing OT. The question is whether the 'client' (whatever that means)
> >>> should be doing it also.
> >>> [13:08] <alown> The network shouldn't need OT. (Algorithms exist that
> >>>allow
> >>> the incoming ops to be arbitarily queued and only processed when
> >>>needed).
> >>> [...]
> >>> [21:21] <josephg> alown: the client always needs to do OT because
> >>>otherwise
> >>> they can't both edit a document live and receive operations from
> >>>people who
> >>> didn't have their ops.
> >>> [21:22] <josephg> the server doesn't need to do OT, although if it
> >>>doesn't
> >>> do OT, it'll punt the OT work to its clients - which will result in a
> >>> higher CPU utilization on mobile devices.
> >>> [...]
> >>> [13:08] <stenyak> i pictured this "server" as being an optional item
> >>>that
> >>> shortcuts the long waits of DHT, rather than something necessary for
> >>> "clients"?
> >>> [13:08] <alown> Hmm.
> >>> [13:08] <alown> I suppose we should define what a 'client' is then...
> >>> [13:09] <alown> We have at least 2 layers of stuff going on here: 1)
> >>>Wave
> >>> OT/operation layer 2) Network routing/P2P layer
> >>> [13:13] <alown> But it is quite plausible something might be doing
> >>>both of
> >>> those
> >>> [13:10] <stenyak> with your pubsub net suggestion, i was picturing 2
> >>>kinds:
> >>> a regular pure p2p peer, and a helper kind of node to route stuff
> >>>quickly
> >>> when a peer is connected to it
> >>> [13:13] <stenyak> so with that picture in mind, layer 1 stuff could go
> >>> directly from peer to peer (if connectivity/firewalls allows), or
> >>>through
> >>> the "helper node" if available
> >>> [...]
> >>> [13:20] <stenyak> [...] all this discussion looks very similar to
> >>> discussing how to design internet+dns, i think the problems are the
> >>>same
> >>> really
> >>> [13:20] <stenyak> or at least we could take some inspiration from it
> >>>maybe
> >>> [13:20] <alown> This was my conclusion last night with josephg. ('The
> >>> problmes should already be solved (see The Internet)')
> >>> [14:09] <stenyak> and The Internets solved the problem how? By having a
> >>> large set of supernodes (dns servers), that may take a whole day to
> >>> propagate updates. The alternative being having the actual IP address
> >>>in
> >>> the first place, or to centralize stuff
> >>> [14:10] <stenyak> (aka use servers everywhere)
> >>> [14:22] <alown> Maybe, but the internet's design is X (where X > 20)
> >>>years
> >>> old, so may not represent the most modern thinking of how to make
> >>> distributed networks.
> >>> [14:59] <alown> (Don't forget that our aim for Wave is at the
> >>>cutting-edge
> >>> of academic research also).
> >>> [...]
> >>> [14:50] <stenyak> i just threw the question at some friends who should
> >>>be
> >>> more up-to-date with networking technologies than me... hopefully they
> >>> comeback with some revolutionary dns-2 design or something that we can
> >>>copy
> >>> [15:18] <stenyak> could give as some ideas: http://openpeer.org/
> >>> [15:18] <stenyak> (it's not a solution, but maybe they did the same
> >>> reasoning we're going through)
> >>> [15:46] <stenyak> another response i got goes along the lines of...
> >>>hard as
> >>> fuck, but if you manage to do it, you are a hero
> >>> [...]
> >>> [15:02] <stenyak> looking at it from a wider perspective, what we want
> >>>is
> >>> similar to having each peer shout at the whole world "here i am,
> >>>anything
> >>> got something for meeee?" in some way that doesn't clog the internet
> >>>tubes,
> >>> and that is so fast as shouting would be. i start to think it's not
> >>> physically possible to do that...
> >>> [15:03] <stenyak> if publickeys were handed to people based on the
> >>> location, then we could have routing tables similar to how internet
> >>> currently works
> >>> [15:03] <stenyak> but pubkeys are... well, random. so that kind of
> >>>routing
> >>> that allows anyone to connect to an arbitrary IP in a matter of
> >>> milliseconds is impossible, i believe
> >>> [15:04] <alown> So, we end up with DNS for public keys?
> >>> [15:04] <stenyak> something like dns, but much faster [wrt. propagation
> >>> times]
> >>> [15:05] <stenyak> so in essence, a tree of servers or whatever (which
> >>>is
> >>> similar to how wave currently works, right?)
> >>> [15:05] <alown> Heh. But the whole point was to avoid the tree system
> >>> currently (since it is susceptible to netsplits)
> >>> [...]
> >>> [15:56] <stenyak> maybe the real question could be: how do we make DHT
> >>>much
> >>> faster?
> >>> [16:14] <stenyak> once the initial discovery process is finished, the
> >>> transmission of data will not have the lag associated with DHT, so
> >>>even if
> >>> DHT takes 10 seconds, that could be acceptable
> >>> [16:15] <stenyak> i.e. a new peer takes 10 seconds to be discovered by
> >>>the
> >>> rest of participants collaborating in a wave
> >>> [16:16] <stenyak> (or viceversa.. the new peer takes 10 seconds to
> >>>discover
> >>> the participants)
> >>> [...]
> >>> [16:25] <stenyak> this could shed some light:
> >>>
> >>>
> >>>
> http://en.wikipedia.org/wiki/Distributed_hash_table#Algorithms_for_overl
> >>>ay_networks
> >>> [19:06] <stenyak> http://dsn.tm.kit.edu/english/2936.php
> >>> *...4) Routing **p2p **messages/events in a pure P2P system (part 5):*
> >>> [21:03] <josephg> [...] For now, I want wave to be p2p in the same way
> >>>that
> >>> git is p2p.
> >>> [21:04] <josephg> that is, I want the core algorithms & data
> >>>structures to
> >>> use P2P-capable algorithms, and probably the wave servers will do p2p
> >>> between themselves (this is easy because they'll all be both named and
> >>> accessable)
> >>> [21:06] <josephg> as for client-to-client p2p, there's a few options
> >>> depending on what kind of use cases we want to support - but I want to
> >>> worry about getting the algorithms p2p-capable first. If you're keen
> >>>to set
> >>> up an anonymous, distributed wave system over a DHT - well, I want to
> >>>first
> >>> make that possible
> >>> [21:15] <josephg> .... and as for ipv6, network admins _love_ NAT now
> >>>that
> >>> we have it
> >>>
> >>>
> >>> *5) Implementing "undo": invertibility, tombstones, edge cases, TP2:*
> >>> [00:17] <alown> I am not sure how an 'undo stack' is going to work (at
> >>>all)
> >>> with federation...
> >>> [00:18] <josephg> well, you just do undo at the application level
> >>> [00:19] <josephg> "submit op which inserts text" ... later "submit op
> >>>which
> >>> removes text"
> >>> [00:19] <josephg> you don't need OT for that.
> >>> [00:20] <josephg> I imagine like, a semantic undo. In the client you
> >>>can
> >>> imagine making an undo op (which might not necessarily rollback an
> >>> operation (because of tombstones and all that))
> >>> [00:20] <josephg> ... but would seem that way as far as the user is
> >>> concerned
> >>> [00:21] <josephg> then if the user hits ctrl+z, you can transform that
> >>> operation up to the current version and apply it
> >>> [00:21] <josephg> - the fact that its an undo isn't really relevant.
> >>> [00:21] <josephg> the bad thing about losing invertability is doing
> >>> playback
> >>> [00:21] <josephg> - because you can't scrub back through time
> >>> [00:21] <alown> But you have all the operations since the start, so
> >>>you can
> >>> play forward at least?
> >>> [00:23] <josephg> yeah exactly.
> >>> [00:23] <josephg> ... and make like, keyframes of the document
> >>> [00:23] <josephg> - and play forward from them or something.
> >>> [00:23] <alown> Hmm, so you can do the step-back without recalculating
> >>>the
> >>> entire document?
> >>> [00:24] <alown> I don't really like the idea of then having another
> >>> datastructure to have to pass around...
> >>> [00:24] <josephg> right - if you have a snapshot at version 1000, and
> >>>the
> >>> user is looking at 1010 and they try to step back to 1009, you can just
> >>> replay ops 1001-1009 on that version 1000 snapshot
> >>> [00:24] <alown> What was the problem with invertible operations (I
> >>>don't
> >>> understand OT enough yet to be able to properly comment on that side).
> >>> [00:25] <alown> (Other than it confuses people?)
> >>> [00:25] <josephg> hahaha actually people seem to love invertability
> >>> [00:25] <josephg> I don't know why.
> >>> [00:25] <josephg> I've been trying to remove it from sharejs, and
> >>>everyone
> >>> gets sad.
> >>> [00:26] <josephg> the problem is that if I make an op which deletes the
> >>> whole document (version 100, say) then I undo that operation
> >>> [00:26] <josephg> and you insert in the middle of the document at
> >>>version
> >>> 100, then your op gets transformed to do that insert at the start of
> >>>the
> >>> document instead at version 101 (because the content has disappeared)
> >>> [00:26] <josephg> and it never goes back to the middle of the document.
> >>> [00:27] <josephg> so, with tombstones you can get around that by
> >>>having a
> >>> 'resurrect' operation
> >>> [00:27] <josephg> (so deleting the whole document turns the whole
> >>>document
> >>> into tombstones, then we can resurrect them all again in the inverse)
> >>> [00:28] <josephg> but you can't invert an insert - because deleting
> >>>leaves
> >>> the tombstone there
> >>> [00:28] <josephg> and if you have a 'real delete' operation, then yeah,
> >>> you're back in the hole
> >>> [00:28] <josephg> also, with wave in particular, inverting is really
> >>> complicated
> >>> [00:29] <josephg> - see, if the wave says "<annotation bold:true>blah
> >>> blah<annotation bold:false> not bolded"
> >>> [00:29] <josephg> then if you insert at the end of the "blah blah",
> >>>it'll
> >>> automatically get bolded.
> >>> [00:30] <josephg> ... so if the text isn't bolded, and then you bold it
> >>> while I insert at the end of the text, you need to make sure my text
> >>> _isn't_ bolded or something
> >>> [00:31] <josephg> .... and yeah, I can't remember - but there's these
> >>> horror cases that I remember kept me from sleeping when I tried to
> >>> reimplement wave's OT code in C
> >>> [00:31] <alown> hmm
> >>> [00:31] <josephg> and it would have been fine if it wasn't invertible.
> >>> Well, at least it would have been tollerable.
> >>> [00:33] <josephg> So yeah. Conclusion: You can make invertability
> >>>work, but
> >>> its kind of a bitch, and you can't make it work for TP2
> >>> [00:33] <josephg> which means it won't work if we're federating
> >>> [00:33] <alown> How are we hacking around that currently then?
> >>> [00:33] <josephg> well, we don't do TP2
> >>> [00:34] <josephg> remember, federation just uses a bad version of the
> >>> current client-server protocol
> >>> [00:34] <josephg> - arranged in a tree of servers
> >>> [00:34] * alown goes and looks up which one TP2 was again
> >>> [00:35] <josephg> ... its the one that says you don't need a canonical
> >>> ordering of operations
> >>> [00:35] <josephg> sharejs and wave both use the server to pick the
> >>>order of
> >>> operations (based on which order they reach the server)
> >>> [00:35] <josephg> and then they use incrementing version numbers based
> >>>on
> >>> that order
> >>> [00:35] <alown> ah yep.
> >>> [00:35] <josephg> -> for p2p, that doesn't work because you don't have
> >>>a
> >>> centralized server, and anyone can send messages to anyone
> >>> [00:36] <josephg> and yeah, you need TP2 for that (which sort of says
> >>>you
> >>> can apply ops from 3 different sites in any order and it still works)
> >>> [00:37] <josephg> - and apparently someone proved that if you make it
> >>>work
> >>> for 3 sites, it works for any number of sites
> >>> [00:43] <alown> Anyhow, I can see leaving inversion out for
> >>>simplicity, but
> >>> don't yet understand why it can't be made to work with TP2.
> >>> [00:59] <alown> Hmm. Seen 'A Sequence Transformation Algorithm for
> >>> Supporting Cooperative work on Mobile Devices'?
> >>> [01:02] <josephg>
> >>>
> >>>
> >>>
> http://research.microsoft.com/en-us/um/redmond/groups/connect/cscw_10/do
> >>>cs/p159.pdf
> >>> ?
> >>> [01:15] <alown> The main feature is its use of storing local/remote
> >>> operations and processing them much later than receipt time.
> >>> [01:17] <alown> ABT satisfies TP1+2, so looks like this should(?)
> >>> [01:19] <josephg> need to read it
> >>> [01:19] <josephg> ... I'll go through it later
> >>>
> >>>
> >>> *6) Usability of a pure p2p system in Real Life (tm):*
> >>> [12:13] <alown> We also don't know if storing ops in a DHT is efficent
> >>> enough for our use case...
> >>> [12:14] <stenyak> in any case, let's say i fire up my wavep2p android
> >>> client and want to check for any new waves
> >>> [12:14] <stenyak> i definitely won't put up with a wait of 30 seconds
> >>>when
> >>> i have "this damn fast 4g connection!" in my cellphone
> >>> [12:14] <stenyak> i mean, that's the point of view of six pack joe
> >>> [12:14] <stenyak> and joe is definitely right..
> >>> [12:15] * alown thinks of the hours it took to download the bitcoin
> >>> blockchain from the p2p system
> >>> [12:15] <stenyak> or browse through freenet, or whatever... its painly
> >>>slow
> >>> [12:16] <stenyak> in the end, i think that most users won't be running
> >>>a
> >>> full blown peer, but will be relying on an external server instead
> >>> [12:16] <stenyak> i.e. nobody runs their own email servers nowadays
> >>> [12:16] <stenyak> and the same can happen with wave
> >>> [12:16] <alown> Should a mobile client be doing the full p2p
> >>>federation, or
> >>> simply talking to a server which does it...
> >>> [12:16] <stenyak> the few who decide to run a full-blown wave peer,
> >>>should
> >>> be aware of the problems
> >>> [12:17] <alown> So, this should be less of a problem since the only
> >>>nodes
> >>> doing p2p will be proper full-time connected servers?
> >>> [12:17] <stenyak> the thing is, we can assume most people wont fire up
> >>> their own xmpp server, but go for jabber.org account
> >>> [12:17] <stenyak> and the same thing will presumably happen for wave,
> >>> simply because it's easier to do
> >>> [12:18] <stenyak> which doesn't pervent me from running my own
> >>>full-blown
> >>> wave server
> >>> [12:18] <stenyak> but that's a use case in which the user knows the
> >>> limitations
> >>> [12:19] <stenyak> [...] you and i will run several full-blown wave
> >>>peers at
> >>> home, at our parent's house, or whatever, but we'll know and accept the
> >>> problems
> >>> [12:19] <stenyak> i think that's the way to think about the problem
> >>> [12:19] <stenyak> heck, most people use github for permanent [git]
> >>> connectivity ;-)
> >>> [12:19] <stenyak> instead of opening ports to their laptop in their lan
> >>> [12:19] <stenyak> and those are the tech-savvy people...
> >>> [12:20] <alown> So, we have a p2p system between wave servers and
> >>>superwave
> >>> servers, with clients connecting to the server rather than doing the
> >>>p2p
> >>> itself...
> >>> [12:20] <stenyak> i'm not saying it's the way we should do it. i'm
> >>>saying
> >>> that's the way it most probably will pan out, because it's already
> >>> hapennign in 100% of the existing p2p protocols i know of
> >>> [12:20] <alown> Hmm...
> >>> [12:21] <stenyak> so we should plan for that instead of a theoretical
> >>>pure
> >>> p2p world
> >>> [12:21] <stenyak> if we assume there's servers like github, bitbucket
> >>>and
> >>> sourceforge, then suddently most of the problems go away, while still
> >>>not
> >>> preventing from people to run fully p2p if they want
> >>>
> >>>
> >>> *7) Comparison with BitTorrent and P2P-TV technologies:*
> >>> [12:21] <alown> BT doesn't have huge servers (and with magnet has
> >>>actually
> >>> move in the opposite direction).
> >>> [12:21] <stenyak> BT has no real-time needs
> >>> [12:22] <stenyak> that's why they can afford DHT
> >>> [12:22] <stenyak> dht could be used for simulating a forum-like
> >>>discussion
> >>> in wave. but we can't force that restriction from the server
> >>> [12:22] <stenyak> (i say forum-like, because people don't expect
> >>>reaction
> >>> within seconds there)
> >>> [12:23] <alown> How did iplayer do its live p2p broadcastinºg?
> >>> [12:23] * stenyak googles what iplayer is
> >>> [12:23] <alown> Sorry, BBC iPlayer is their TV-over-the-internet
> >>>system.
> >>> [12:24] <alown> Originally it used a p2p system, but got lots of
> >>>negative
> >>> press (because of assosciation with BT since it used p2p), so it now
> >>>uses a
> >>> centralized system instead. (And their bandwidth costs are much
> >>>higher).
> >>> [...]
> >>> [12:25] <stenyak> i seem to recall other [p2p] tv clients
> >>> [12:25] <stenyak>
> >>>
> >>>
> >>>
> http://wiki.xbmc.org/index.php?title=HOW-TO:Play_free_P2P_(peer-to-peer)
> >>>_online_streaming_TV
> >>> [...]
> >>> [12:26] <alown> Found a paper titled "RT-P2P: A Scalable Real-Time
> >>> Peer-to-Peer System with Probabilistic Timing Assurances" (google for
> >>>it)
> >>> [12:28] <alown> Lookt at the paper I mentioned. It relies on 'super
> >>>nodes'
> >>> to enable it to keep low latencies...
> >>> [...]
> >>> [12:27] <stenyak> but i'd be wary of using this (p2p tv) as an
> >>>inspiration.
> >>> i know there's delay of 10-30 seconds from my TV Formula1 image to the
> >>> telemetry that comes through HTTP from formula1.com website. this is
> >>> regular TV, and they don't care about 30 seconds of lag
> >>> [12:27] <stenyak> the only real problem of p2p tv is avoiding much
> >>>jitter
> >>> [12:27] <stenyak> as long as the stream arrives and is viewable, a
> >>>delay of
> >>> a minute doesn't matter that much
> >>> [12:28] <alown> True.
> >>>
> >>>
> >>> *8) Identifying participants (part 1):*
> >>> [12:09] <alown> I am also no longer sure what an 'account' should look
> >>> like, since it has no reason to be stuck to a domain...
> >>> [12:10] <stenyak> current wave discovery works by using the domain
> >>>name of
> >>> the email-address-like list of participants
> >>> [12:10] <stenyak> but here we're talking about hashes, public keys or
> >>> whatever
> >>> [12:10] <stenyak> which do not (necessarily) point to an particular
> >>>IP:PORT
> >>> or whatever
> >>> [12:10] <alown> Exactly the problem...
> >>> *...8) Identifying participants (part 2):*
> >>> [12:33] <stenyak> would it make sense that, while some participants are
> >>> identified by a pubkey (or whatever), many of them could be identified
> >>>by a
> >>> user@domain address, with which any peer can quickly locate
> supernodes?
> >>> [12:33] <stenyak> i mean some kind of dual "pubkey and optional domain
> >>> email-like addr" for the participants list
> >>> [12:34] <stenyak> the optional part being essential in the broader
> >>>internet
> >>> [12:34] <alown> Isn't that exactly what using Mozilla Persona would do
> >>>(map
> >>> user@domain to some public-key we can use)
> >>> [12:34] <alown> Removing the need for us to have to roll yet-another
> >>> authentication system.
> >>> [...]
> >>> [12:38] <stenyak> the idea would be that, for a person to be a
> >>>participant
> >>> in a wave, you *require* his pubkey. optionally, you may have acquired
> >>>ths
> >>> pubkey by asking "wave.google.com" about the user "joe", getting his
> >>> pubkey
> >>> as a result.
> >>> [12:39] <stenyak> and now that you have the pubkey and one of many
> >>>possible
> >>> email-like addresses (in this case j...@wave.google.com), then you can
> >>>use
> >>> the email-like address for displaying in the UI
> >>> [12:39] <stenyak> this means that, whoever wants to run pure p2p peers,
> >>> will have to give his pubkey
> >>> [12:39] <stenyak> and whoever uses the more traditional style, can
> >>>simply
> >>> give his email-like addr
> >>> [12:39] <stenyak> and the participants list will show a simple
> >>>email-like
> >>> address most of the time
> >>> [12:40] <alown> Do we then allow anyone to 'log in' to any wave server
> >>> running at any domain, since it should no-longer make any difference
> >>>where
> >>> they are in the network...
> >>> [12:41] <stenyak> yes, that's needed for world-wide-public waves,
> >>>which is
> >>> equivalent to a read-only forum on the net
> >>> [12:41] <stenyak> then there could be server-public waves, which is
> >>> equivalent to requiring sign-in to view a forum (and coincidentally the
> >>> current implementation of public waves in WiaB, right?)
> >>> [12:43] * alown has never tested what happens with public waves in the
> >>> current federation system
> >>> *...8) Identifying participants (part 3):
> >>> *
> >>> [21:35] <josephg> - Who is a user? If a user is sten...@example.com,
> >>>then
> >>> we can put a server at example.com and it can hold operations for you
> >>> [21:36] <josephg> ie, if I add you to a wave, my computer (or my wave
> >>> server or something) can send a message to example.com to say "Yo,
> >>>here's
> >>> some ops you should know about"
> >>> [21:36] <josephg> that would be similar to a mailbox
> >>> [21:37] <josephg> ... and it would work pretty well. Bear in mind that
> >>> there's no reason operations have to go through the wave server at
> >>> example.com - if we're both on a LAN together, we could discover one
> >>> another through DNS service discovery and send ops directly
> >>> [21:37] <josephg> .. without going through our respective wave servers
> >>> [21:38] <josephg> However - if our identities aren't tied to a domain
> >>>(eg
> >>> bitcoin), then we'll need to use a dht or something.
> >>> [21:42] <stenyak> the conclussion i've arrived at is that "users"
> >>> ultimately are a publickey (for which they have the privatekey). this
> >>>is
> >>> inconvenient for people to "add you to a wave", so a possibility would
> >>>be
> >>> to have a friendlyname=>pubkey server converter. this way people can
> >>>add "
> >>> sten...@example.com", by first finding out what the pubkey for
> >>> sten...@example.com really is
> >>> [21:43] <stenyak> the friendlyname would be optional, and in LAN
> >>> environments you could directly use the pubkey (instead of the friendly
> >>> name)
> >>> [21:43] <josephg> I think people will be more than happy to use a
> >>>frienly
> >>> name in a lan environment too
> >>> [21:43] <stenyak> discovery in a local network could be done with
> >>>bonjour
> >>> or something too (not just dns)
> >>> [21:44] <josephg> I <3 dns-sd
> >>> [21:44] <stenyak> [...] maybe they already have a contact list (read,
> >>>list
> >>> of friendlyname<>pubkey equivalences) they can use in the UI (even if
> >>>the
> >>> underlying system will use pubkeys anyway)
> >>> [21:44] <stenyak> and by contact list, i really mean a cache of some
> >>>sort
> >>> [21:45] <stenyak> (not some specific, complex roster system)
> >>> [21:45] <josephg> and you can do friendlyname -> pubkey really easily
> >>>by
> >>> just storing the pubkey on the user's domain
> >>> [21:45] <josephg> so, have the example.com webserver host
> >>> https://example.com/.wellknown/stenyak
> >>> [21:46] <josephg> = your public key.
> >>>
> >>>
> >>> *9) P2P anonymity (peers that want to anonymously lurk in a wave) (part
> >>> 1):*
> >>> [12:48] <stenyak> by the way, what about non-participants that simply
> >>>want
> >>> to lurk a wave?
> >>> [12:49] <stenyak> e.g. i'm given a wave uri
> >>> (wave://look_at_these_kittens_wave), and want to view it
> >>> [12:49] <alown> Whilst a wave is public, as soon as they 'read' the
> >>>wave,
> >>> they would have a metadata wavelet created, so would become a
> >>>participant
> >>> (if read-only).
> >>> [12:50] <stenyak> and from then on, whenever the wave changes, someone
> >>>will
> >>> try to make the change reach the peers with my privkey
> >>> [12:50] <stenyak> supposedly..
> >>> *...9) P2P anonymity (peers that want to anonymously lurk in a wave)
> >>>(part
> >>> 2):*
> >>> [21:18] <josephg> stenyak: interesting point about people who want to
> >>>not
> >>> participate but follow a wave anyway - its really bad if other people
> >>>can
> >>> tell that they're there (assuming the wave is public).
> >>> [21:18] <josephg> I guess we just need to make sure that the metadata
> >>>wave
> >>> is invisible, and then its ok..
> >>> [21:21] <stenyak> invisible.. to what peer/s? surely those that are
> >>> transmitting deltas to the lurkers will need to know they exist?
> >>> [21:21] <stenyak> (maybe some of the algorithms behind freenet can help
> >>> with this)
> >>> [21:21] <stenyak> (or even TOR)
> >>>
> >>>
> >>> *10) Encryption of waves:*
> >>> [21:47] <josephg> for waves themselves, I'm imagining giving each wave
> >>>an
> >>> AES key
> >>> [21:47] <josephg> then storing an encrypted version of the key for each
> >>> participant on the wave
> >>> [21:48] <josephg> .... anyway, that way anyone who has the AES key can
> >>>read
> >>> all ops on the wave
> >>> [21:48] <josephg> and can participate (because they can encrypt ops
> >>>for the
> >>> wave)
> >>>
> >>>
> >>> *11) Addition and removal of participants, and their ability to read
> >>>past
> >>> and future wave versions/deltas:*
> >>> [21:48] <stenyak> what about removing a user from a wave?
> >>> [21:49] <josephg> worst case, we can just make a new key and re-add
> >>> everyone using the new key
> >>> [21:49] <josephg> and keep around the old key too
> >>> [21:49] <josephg> so people can still read the old ops as well
> >>> [21:49] <stenyak> the user can access their browser cache for all we
> >>>care..
> >>> if you ever read it, there will be ways to do it. "download now
> >>>wave-spy to
> >>> read waves you were removed from!"
> >>> [21:49] <stenyak> so providing an official way sounds better
> >>> [21:50] <stenyak> the AES key could change at any point in time, e.g.
> >>> whenever a new users is added (to prevent them accessing the history),
> >>>or
> >>> deleting them (to prevent them from reading future history)
> >>> [22:32] <josephg> um - in wave, we let new users see the whole history
> >>> [22:40] <stenyak> but that use case could be desirable, right? and if
> >>>we
> >>> support modification/versioning of the AES key, we might as well allow
> >>>that
> >>> too? the equivalent in email world would be to forward an email,
> >>>removing
> >>> the existing quotes
> >>> [23:17] <josephg> Yep definitely.
> >>>
> >>>
> >>> --
> >>> Saludos,
> >>> Bruno González
> >>>
> >>> _______________________________________________
> >>> Jabber: stenyak AT gmail.com
> >>> http://www.stenyak.com
> >>>
> >
>
>
>
