[sldev] Re: Exciting reuter's post about OpenSim - project to create open source version of SL Servers

[Callum Lerwick]

On Sat, 2007-09-08 at 16:38 +0200, Dale Glass wrote:
> On Saturday 08 September 2007 07:13:58 Callum Lerwick wrote:
> > On Sat, 2007-09-08 at 06:11 +0200, Dale Glass wrote:
> > > It also makes a lot of caching impossible as with no central server
> > > there's no universal ID for an object (probably fixable by using
> > > content based hashes)
> >
> > A content hash, of course.
> Ok, but do you want to preserve ownership on your grid?

That's up to the creator of the asset, to sign their work in some way.
Its what people already do.

> Say, who is the owner or the creator of a texture or object on this grid? 
> If it goes by content hash there can't be two separate copies by different 
> people.
> 
> Take a box for instance. The second box rezzed will have the same hash as 
> the first one. Does that give them the same LLUUID? If not, where does 
> that LLUUID come from?

You tag the asset with some kind of meta-data, which becomes part of the
asset thus part of the hash. This can be as simple as signing your name
in the corner of a texture, (Yeah yeah, wouldn't work so well if the
texture is tiled, but this would work nicely on avatar textures which
have areas that aren't shown.) or putting your name in the scripts you
write.

> > P2P-ish technology. Its nothing but a big distributed cache anyway. It
> > will become as basic an internet service as DNS is. All ISPs will run a
> > "seed" farm for its customers. Or at least contract it out to some
> > really big seed farms. :)
> 
> P2P from where to where? Example situations:
> 
> Situation A:
> I login in sim A, obtain a house and save it to my inventory.
> I cross to sim B, don't stop there and don't do anything, and cross to C.
> I try to rez the house in sim C.
> 
> How does it get rezzed?

Well, from your own point of view, its retrieved from your own cache.
Others query the "asset mesh", of which you participate in, so you can
seed your own assets.

> Situation B:
> I login in sim A, obtain a house and save it to my inventory.
> I logout, log back in to some completely different part of the grid, 6 
> months later.
> I try to rez the house.
> 
> How does it get rezzed? Does it get rezzed at all?

You rez it from your own storage, if you happen to still have a copy.
Otherwise your client, and other people's clients query the asset mesh
for your asset.

If its not out there, well its your own damn fault for not keeping a
copy. :)

> Easiest way to do it seems to have the user keep the inventory and transmit 
> it to the sim on rez, but that means that you lose your inventory if 
> anything happens to your computer.

Unless a copy is still out in the mesh somewhere.

But if you really care about something, its up to you to ensure a copy
is retained somewhere, somehow. Its really no different from now. Except
that if you have or make something that's popular enough, everyone else
will mirror it for you, for free. :)

" Only wimps use tape backup: _real_ men just upload their important
stuff on ftp, and let the rest of the world mirror it ;) "
  --Linus Torvalds, 1996-07-20

> If on the other hand, inventory is held by the sim that gave it to you, 
> then that means it's lost if that sim is removed.

The sim could very well also participate in the asset mesh, making
itself the preferred point of contact for clients connected to it, but
it wouldn't be required. No different from running apache and sendmail
on the same box.

> Also there either needs 
> to be a central DB to figure out which sim has the data, or you have the 
> same problem as above.

Easy. A Kademlia based DB.

http://en.wikipedia.org/wiki/Kademlia

> > Identify all avatars by a PGP key. Build a trust web with your friends.
> > All assets referenced or belonging to an avatar get signed with that
> > avatar's key. Combined with the referencing based on content hash, ta
> > da, can't slip anything in without detection.
> >
> > All the pieces are there, you just have to put them together. :)
> 
> While I really like PGP that doesn't sound like a very friendly system :-) 
> TrustNet is hard enough to explain already.

It doesn't have to be any more complex that the existing "offer
friendship" system.

This would possibly be a separate trust web from "normal" PGP though.

The trust web is just a bonus, really. Identifying avatars via a public
key, is the key thing. :)

> I have to agree with Laurent here. This could be very cool, but it won't be 
> a competitor to LL. It'll be a completely different beast.

Just like the internet vs. Compuserve.
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