[Opensim-users] [Opensim-dev] Grid Numberging

Mon Nov 3 15:49:17 UTC 2008

I am starting to see the 'problem' as two distinct issues, depending on
one's focus. In the provider-centric view of LL, with many nods to DRM, what
they do makes sense. They are, after all, trying to take a modicum of
responsibility for preserving the ownership and related rights on the asset.

In the more user-centric world we seem to feel pulled toward, a more
distributed scenario makes more sense, performance impacts notwithstanding.

The key to the most  reasonable architecture, as a result, will depend on
how one optimizes for these orientations.

The short story is, the shortcomings of the existing protocol are being
manifest in terms of the direction we are pushing it in with this
application; and we aren't going to to be able to influence the direction
taken except in the most limited ways, until we a) produce a client, so we
have control of both ends of 'the pipe', or b) get more thoroughly involved
in LL's open source client efforts.

The bottom line is, as long as they dictate the protocol, we have to play
ball on their field, by their rules. And as long as we refuse to take up
some leadership roles with respect to a/the client, they are in complete
control of the protocol. That they agree to play along with us at all is
just a courtesy.

Cheers,
James

On Mon, Nov 3, 2008 at 9:31 AM, Diva Canto <diva at metaverseink.com> wrote:

>  Sure, I'll do this so not to get stuck. But this is so wrong...
> Region servers should not *cache* assets. Period. It's an unnecessary
> burden in two dimensions:
> 1) Performance.
> 2) Security of assets.
>
> Any dealings between assets and the viewer should be done directly between
> the viewer and asset servers. Region servers should be out of the loop.
> Except, of course, for serving the objects that are inworld. But the act of
> dragging an object from inventory to the world should result in a *copy*
> being created (posted either from the viewer or from the user's asset
> server) in the region server's asset *storage* (not cache), and not this
> horrendous optimization that the LL system currently does, and that pretty
> much stops the idea of scalability on its tracks.
>
> Is anyone here involved with LL Viewer development? I wonder how hard it
> would be for them to interpret steganographic urls in uuids... or do the
> right thing and use decent global resource identifiers, but I suspect that's
> way off the radar.
>
> Stefan Andersson wrote:
>
> Diva,
>
> there's a blindingly simple remedy; start treating the asset guid
> as something private between the region and the client, and publicly refer
> to assets by url instead.
>
> In effect, the fact that we are storing the assets untampered in the
> database is just a legacy issue. If we were to start processing the asset
> data more intelligently, things would look a lot differently.
>
> Suppose we;
>
> a) on asset upload, processed the asset and changed guids to urls, firstly
> by lookup (is this already an asset guid known to the region) then by url
> synthetization (create an asset storage url (maybe using the users home
> asset server that we already said we would store... ;D ) , post the binary
> to that and change all guid references in the asset to that)
>
> b) on asset download (from asset storage) processed the asset and changed
> urls to guid, again firstly by lookup (is it already known to the region)
> then, by fetching the asset by url and assigning it a guid.
>
> This would mean that the client, when it refers to an asset, actually
> requests it by the local guid that the region has assigned it - more as a
> local cache key than a public asset id.
>
> I believe this would solve the whole thing, more or less. I would love to
> see a proof of concept - it should be fairly easily thrown together,
> probably as a custom asset cache.
>
> Best regards,
> Stefan Andersson
> Tribal Media AB
>
> Join the 3d web revolution : http://tribalnet.se/
>
>
>
>
> ------------------------------
>
> Date: Sat, 1 Nov 2008 07:52:33 -0700
> From: diva at metaverseink.com
> To: opensim-users at lists.berlios.de
> Subject: Re: [Opensim-users] [Opensim-dev] Grid Numberging
>
> The only reason why I'm suggesting the encoding hack as a horrible option
> not to be immediately discarded  is that it is probably the simplest thing
> to do for the LL Viewer to start pulling assets from different places on the
> internet. From all I know, the LL Viewer is deeply rooted on UUIDs for
> universal identification; refactoring this will be a massive undertaking on
> the viewer. But simply giving semantics to UUIDs would not be that big of a
> deal. I'm thinking a few conditionals here and there:
>
> url = RetrieveUrl(uuid)
> if ItsASyntacticallyValidUrl(url)
>    try to do the right thing, please
> else
>    do what you do now
>
> or something to this effect.
>
> Of course, we're hitting our heads again on the pre-condition of using the
> LL Viewer...
>
> Dickson, Mike (ISS Software) wrote:
>
>  We really don't want to start encoding info into a GUID. The RFC that
> describes them pretty much details what kinds of entropy can be used.
>
>
>
> I've been thinking for a while that the handle service (
> http://www.handle.net) might be a nice way to do a URL style mechanism to
> refer to assets and such not on a local server.  It's been a while since I
> looked at it but it's pretty much designed for the purpose and there's a
> proxy architecture already defined for it.
>
>
>
> Mike
>
>
>
> *From:* opensim-users-bounces at lists.berlios.de [
> mailto:opensim-users-bounces at lists.berlios.de<opensim-users-bounces at lists.berlios.de>]
> *On Behalf Of *Diva Canto
> *Sent:* Saturday, November 01, 2008 9:05 AM
> *To:* opensim-users at lists.berlios.de
> *Subject:* Re: [Opensim-users] [Opensim-dev] Grid Numberging
>
>
>
> Actually, I just realized that the problem is already much worse than I
> thought.
> The practices that we are all doing around opensim completely invalidate
> the concept of uniqueness in UUIDs. This comes from the fact that UUIDs are
> being externalized into DBs and XML representations, which are then being
> imported elsewhere. As people reuse entire DBs and XML files to recreate the
> same worlds in different grids, uniqueness goes down the drain. So
> definitely, forget about "Universal" Unique Identification with UUIDs;
> uris/urls are absolutely required for universal naming. The only way to
> savage UUIDs would be use part of their representation to deterministically
> code up the ip/port of where they come from.
>
> Stefan Andersson wrote:
>
> And the whole thread started with suggesting we allocate information bits
> to encode semantics. Which drastically heightens the risk of collisions,
> intentional or malicious.
>
> Just see guids as private to the trust domain, and we'll all fine. Grids
> should be publicly referred to by something riches, as an uri/url for
> example.
>
> Best regards,
> Stefan Andersson
> Tribal Media AB
>
> Join the 3d web revolution : http://tribalnet.se/
>
>
>
>  ------------------------------
>
>
> Date: Fri, 31 Oct 2008 20:10:41 -0700
> From: diva at metaverseink.com
> To: opensim-users at lists.berlios.de
> Subject: Re: [Opensim-users] [Opensim-dev] Grid Numberging
>
> Not to mention the dudes and dudettes who generate region UUIDs by hand...
> (a-hem)
> Purely random UUIDs that don't encode higher-order information are too
> fragile when there is a chance that people will get their hands on them. I'm
> not even talking about malicious manipulation, just simple human
> intervention.
>
> Frisby, Adam wrote:
>
>  Yeah, the reason I said 'almost' wasn't because of a good UUID generator, - it's the bad ones.
>
>
>
> IE, people using bad random sources, etc which dramatically increase the chance of a collision - ie if you are only getting 30 bits of randomness, you could run into a collision fairly quickly.
>
>
>
> Adam
>
>
>
>
>
>  -----Original Message-----
>
> From: opensim-users-bounces at lists.berlios.de [mailto:opensim-users <opensim-users>-
>
> bounces at lists.berlios.de] On Behalf Of Sean Dague
>
> Sent: Friday, 31 October 2008 4:48 PM
>
> To: opensim-users at lists.berlios.de
>
> Subject: Re: [Opensim-users] [Opensim-dev] Grid Numberging
>
>
>
> Dr Scofield wrote:
>
>
>
>  Frisby, Adam wrote:
>
>
>
>  Shouldn't UUIDs by definition be unique?
>
>
>
>
>
>
>
> IE – if your generating them randomly a collision is almost
>
> guaranteed to never ever occur.
>
>
>
>  "almost" being a key word here...
>
>
>
>  "...after generating 1 billion UUIDs every second for the next 100
>
> years, the probability of creating just one duplicate would be about
>
> 50%. The probability of one duplicate would be about 50% if every
>
> person on earth owns 600 million UUIDs." <http://en.wikipedia.org/wiki/UuidJusttokeep>
>
>   <http://en.wikipedia.org/wiki/UuidJusttokeep>
>
> http://en.wikipedia.org/wiki/Uuid <http://en.wikipedia.org/wiki/UuidJusttokeep>
>
>   <http://en.wikipedia.org/wiki/UuidJusttokeep>
>
> Just to keep " <http://en.wikipedia.org/wiki/UuidJusttokeep>almost" in perspective,
>
>
>
>         -Sean
>
>
>
> --
>
> Sean Dague / Neas Bade
>
> sdague at gmail.com
>
> http://dague.net
>
>
>
>
>
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