[Opensim-dev] Always mutable assets in OpenSim -- does it make sense?

[Frisby, Adam]

Well, it in theory makes a degree of sense - it's just a case of doing it properly.

Regards,

Adam

> -----Original Message-----
> From: opensim-dev-bounces at lists.berlios.de [mailto:opensim-dev-
> bounces at lists.berlios.de] On Behalf Of Melanie
> Sent: Wednesday, 17 December 2008 2:38 AM
> To: opensim-dev at lists.berlios.de
> Subject: Re: [Opensim-dev] Always mutable assets in OpenSim -- does it
> make sense?
>
> That is why it needs to be optional. I would never want it for my grid.
>
> Melanie
>
>
> Frisby, Adam wrote:
> > Be careful here however,
> >
> > Because if the hashing algorithm you choose ever gets 'broken' where
> it's possible to calculate a binary against a desired result, then
> people can potentially overwrite existing assets, etc.  A long hash
> tends to act as a good barrier against this. (256bit+ is ideal.)
> >
> > Regards,
> >
> > Adam
> >
> > From: opensim-dev-bounces at lists.berlios.de [mailto:opensim-dev-
> bounces at lists.berlios.de] On Behalf Of Stefan Andersson
> > Sent: Wednesday, 17 December 2008 12:59 AM
> > To: opensim-dev at lists.berlios.de
> > Subject: Re: [Opensim-dev] Always mutable assets in OpenSim -- does
> it make sense?
> >
> > First step would probably be to implement the sha-based binary store
> that you bring up and that we've discussed earlier, so that the
> immutables at least share the same binary data row. Right now, I
> believe we're seing massive duplication when people export/import
> content between worlds. Storing the binaries separately by sha key
> would probably be an low hanging fruit.
> >
> > I would say that it's probably very much up to the service (aka 'the
> grid') how assets should be managed. On an grid that employs a
> consumer/producer division (like a fantasy game) you could probably
> reap dead assets quite aggressively. In a SL business model, it becomes
> harder, as they have to ensure consistent user experience in a
> heterogenous environment.
> >
> > Best regards,
> > Stefan Andersson
> > Tribal Media AB
> >
> >> Date: Sun, 14 Dec 2008 14:48:01 +0900
> >> From: mmazur at gmail.com
> >> To: opensim-dev at lists.berlios.de
> >> Subject: [Opensim-dev] Always mutable assets in OpenSim -- does it
> make sense?
> >>
> >> Hi,
> >>
> >> Melanie's recent thread[1] on updating assets prompted me to put in
> >> writing some thoughts on this topic I've been having.
> >>
> >> I'm curious whether it may be beneficial to make assets mutable.
> AFAIK
> >> assets are currently immutable because of a LL decisions early on to
> >> re-use one asset instance for very popular items sold no-modify.
> This
> >> makes sense for them because they can:
> >>
> >> * clean up unused assets since they own the entire infrastructure
> >> (regions & DBs)
> >> * save on space because they anticipate more identical copies rather
> >> than slightly modified copies
> >>
> >> Perhaps taking the opposite approach in OpenSim would be a better
> fit?
> >> I mean, copying assets when they are transferred between owners, and
> >> modifying them if they are modified in-world. I can see a few
> reasons
> >> this might be beneficial:
> >>
> >> * OpenSim's databases are distributed so cleaning them (reaping dead
> >> assets) is more difficult
> >> * with the advent of distributed asset servers and the long-term
> >> vision of a wide open 3D Internet (like HyperGrid), when an item is
> >> transferred in-world its assets should probably be stored in that
> >> avatar's own inventory DB *anyway*
> >> * disk is cheap, and I wonder which is more wasteful -- multiple
> >> copies of an asset, each differing slightly due to minor edits over
> >> time, or multiple copies of identical assets because they correspond
> >> to different objects in-world
> >>
> >> I see this as a cleaner approach to assets for the future. Sure,
> >> storing duplicate identical assets in a DB can be wasteful, but this
> >> could be alleviated with hashes of the asset or whatnot (I believe
> >> this was brought up on this list before).
> >>
> >> I realize this change would mean deep, possibly breaking, changes
> >> throughout the source code, would take a long time to hash out, etc.
> I
> >> thought I'd throw it out there anyway.
> >>
> >> Your thoughts -- or perhaps clarifications on why this absolutely
> >> cannot be done -- appreciated :)
> >>
> >> Thanks,
> >> Mike
> >>
> >> [1] https://lists.berlios.de/pipermail/opensim-dev/2008-
> December/004025.html
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> >
> >
> >
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