[Opensim-dev] Global identifiers

diva at metaverseink.com diva at metaverseink.com
Sun Aug 29 16:29:47 UTC 2010


I already said this, but let me stress it again.

OpenSim does not use global identifiers for *local* resources (read 
local users). So if you change the name of your users while keeping 
their UUIDs, the names associated with the objects in *your* world will 
be always the latest ones. You don't need a table lookup.

Global identifiers are used *only* in references to external resources 
that have been imported in some way.


Ideia Boa wrote:
>   We see the same problem than Zonja with our grid
> 
> On 29-08-2010 5:27, Zonja Capalini wrote:
>> I see one small problem with this approach: UUIDs are immutable,
>> but it's conceivable that a world operator could allow certain form of
>> updating of user names, while still retaining the same identity
>> (I've had to manually edit user names in some cases in the worlds
>> I administer, for a number of reasons).
>>
>> In this scenario, if an URI is resolved to a name that has changed
>> this can potentially require a lot of updates in the database
>> (e.g., if the foreign user has created many objects in the local world).
>>
>> OTOH, if the URI -> username association is stored in a different table,
>> this table can also keep other, valuable, information, for example the
>> date of the latest resolution, whether the world appears to be active 
>> atm, etc.
>>
>>   /Zonja
>>
>> On Sun, Aug 29, 2010 at 1:44 PM, Melanie <melanie at t-data.com 
>> <mailto:melanie at t-data.com>> wrote:
>>
>>     We should.
>>
>>     Also, we should use extra info in the URI. Reson:
>>
>>     http://www.avination.net:8004/user/44626b40-13d6-4817-b61b-de5df7b5e7e8
>>
>>     The above is totally meaningless. It can't be used to do anything
>>     with unless www.avination.net <http://www.avination.net> exists
>>     and points to a gatekeeper.
>>
>>     However,
>>
>>     http://www.avination.net/user/44626b40-13d6-4817-b61b-de5df7b5e7e8/Melanie+Milland
>>
>>     makes more sense here.
>>
>>     The URI itself provides a "Display name" that the resolver at that
>>     URL can treat as extra path info and ignore, if it chooses.
>>
>>     This would allow us to create a temporary memory cache record of the
>>     UUID -> name mapping that would let us display a prim creator
>>     without a lookup, which is a potentially frequent process.
>>
>>     The sim can take the URL at face value and diassemble it, using
>>     44626b40-13d6-4817-b61b-de5df7b5e7e8 -> "Melanie
>>     Milland at www.avination.net <mailto:Milland at www.avination.net>" for
>>     the cache and returning that to the
>>     viewer as the creator, all without a lookup.
>>
>>     While this doesn't prevent verification of stale URI's from failing,
>>     it does allow to display a meaningful text if that happens.
>>
>>     Melanie
>>
>>     diva at metaverseink.com <mailto:diva at metaverseink.com> wrote:
>>     > Looks like ppl are reading more into this discussion than I
>>     intended.
>>     >
>>     > The hypergrid is up & running with all authentication and
>>     security in
>>     > place, and so are exchanges of content via HG and archives. What's
>>     > missing is *systematic* global identification of resources. OpenSim
>>     > already does that internally for resolving *certain* identifiers
>>     on the
>>     > Hypergrid, but nothing is stored persistently yet. That is going to
>>     > change soon, because 1) I want to make friends & IM work across
>>     the HG
>>     > (so, for example, your foreign friend needs to be identified by
>>     a global
>>     > ID); and 2) we really need to fix the b0rked "creator" field in
>>     OARs/IARs.
>>     >
>>     > This means that we need to write URIs persistently, both in certain
>>     > fields of the DB (which is already prepared for what's coming)
>>     and in
>>     > the archives.
>>     >
>>     > So the issue here is really narrow. Assuming everyone agrees that we
>>     > should use URIs, should we add type information in the URI or
>>     not? Any
>>     > other thoughts on the *form* of these URIs?
>>     >
>>     >
>>     > mysticaldemina at xrgrid.com <mailto:mysticaldemina at xrgrid.com> wrote:
>>     >> May be good to share what your use case is.  As universal are
>>     you suggesting
>>     >> an identifier that separate, potentially un-trusted domains,
>>     would use to
>>     >> identify the same person?
>>     >>
>>     >> Is so I don't think you can do that with two parties, you need
>>     at least one
>>     >> more party to validate that they are the same person, like how
>>     we do with
>>     >> SSL certificates, or with some kind of authentication, like you
>>     send me an
>>     >> email address which gets me to a profile, but I still need to
>>     enter in a
>>     >> password or something to get access to that profile.
>>     >>
>>     >> M.
>>     >>
>>     >> -----Original Message-----
>>     >> From: opensim-dev-bounces at lists.berlios.de
>>     <mailto:opensim-dev-bounces at lists.berlios.de>
>>     >> [mailto:opensim-dev-bounces at lists.berlios.de
>>     <mailto:opensim-dev-bounces at lists.berlios.de>] On Behalf Of Ai Austin
>>     >> Sent: Saturday, August 28, 2010 4:59 PM
>>     >> To: opensim-dev at lists.berlios.de
>>     <mailto:opensim-dev at lists.berlios.de>
>>     >> Subject: Re: [Opensim-dev] Global identifiers
>>     >>
>>     >> diva wrote:
>>     >>> I'm about to introduce global identifiers, so that I can make
>>     friends
>>     >>> and IM work on the hypergrid, and would like feedback on the
>>     best form
>>     >>> of these identifiers.
>>     >>
>>     >>> Here are some options:
>>     >>> ... Thoughts?
>>     >>
>>     >>
>>     >> A couple of thoughts and observations Diva...
>>     >>
>>     >> Could the taxonomy of "types" you use cause problems if the chosen
>>     >> 1-1 mapping for a UUID is not felt to work well i future.
>>     >>
>>     >> "user" is also perhaps a different notion to a specific "avatar"
>>     >>
>>     >> It would be nice if any UUID in a URI you use can be resolved (e.g.
>>     >> to the avatar name) by any host that has the mapping (like the
>>     >> distributed nature of DNS works), so its not dependent on the host
>>     >> continuing to exist, or to be up at the time information on the
>>     >> avatar is sought.
>>     >>
>>     >> AS an example, we have shifted our data bases between machines and
>>     >> have done so 3 or 4 times since we started running OpenSim,
>>     carrying
>>     >> the UUIDs of avatars (and the UIIDs of regions we use) forwards to
>>     >> the new data bases.
>>     >>
>>     >> _______________________________________________
>>     >> Opensim-dev mailing list
>>     >> Opensim-dev at lists.berlios.de <mailto:Opensim-dev at lists.berlios.de>
>>     >> https://lists.berlios.de/mailman/listinfo/opensim-dev
>>     >>
>>     >> _______________________________________________
>>     >> Opensim-dev mailing list
>>     >> Opensim-dev at lists.berlios.de <mailto:Opensim-dev at lists.berlios.de>
>>     >> https://lists.berlios.de/mailman/listinfo/opensim-dev
>>     >>
>>     > _______________________________________________
>>     > Opensim-dev mailing list
>>     > Opensim-dev at lists.berlios.de <mailto:Opensim-dev at lists.berlios.de>
>>     > https://lists.berlios.de/mailman/listinfo/opensim-dev
>>     >
>>     >
>>     _______________________________________________
>>     Opensim-dev mailing list
>>     Opensim-dev at lists.berlios.de <mailto:Opensim-dev at lists.berlios.de>
>>     https://lists.berlios.de/mailman/listinfo/opensim-dev
>>
>>
>>
>> _______________________________________________
>> Opensim-dev mailing list
>> Opensim-dev at lists.berlios.de
>> https://lists.berlios.de/mailman/listinfo/opensim-dev
> _______________________________________________
> Opensim-dev mailing list
> Opensim-dev at lists.berlios.de
> https://lists.berlios.de/mailman/listinfo/opensim-dev



More information about the Opensim-dev mailing list