[Opensim-dev] AssetServer Observations and Suggestions

[Alan M Webb]

A newly created region contains no assets (except for terrain?). Objects 
get rezzed from OAR files and by avatars moving things from their 
inventories, right? These objects reference other objects and assets 
(textures et al) either directly or via object inventory.

In principle, it is sufficient for the asset database to reflect only 
those assets required to support the set of objects considered to be part 
of the permanent region state at any given point in time. Of course, I'm 
assuming here that the assets needed by an objects that are subsequently 
rezzed can be resolved somehow. The approach we have been experimenting 
with locally is to extend the "Not Found" handling to search for an asset 
in a static/dynamic set of other known asset repositories. This should 
make the process transparent to all.

Weeding out abandoned assets can, as everyone has said, by examining the 
point-in-time configuration of the region's permanent state. This could be 
done by a separate process or low-priority thread. As part of this 
approach it would seem logical to have a secondary asset database. Moving 
the unreferenced assets to this "apparently unused asset" database. If an 
asset is not resolved in the local asset database then the first 
alternative location checked is the "apparently unused asset" database. 
The search continues with other independent asset servers according  to 
whatever search algorithm is in effect.

Best regards
Alan
-------------------
T.J. Watson Research Center, Hawthorne, NY
1-914-784-7286
alan_webb at us.ibm.com



From:
Melanie <melanie at t-data.com>
To:
opensim-dev at lists.berlios.de
Date:
02/09/2009 10:33 AM
Subject:
Re: [Opensim-dev] AssetServer Observations and Suggestions



In a normal grid use scenario (OSGRID) I believe that most assets 
are _initially_ created by uploading them through the viewer. Even 
though they can be deleted, few people delete their textures, since 
they are always needed for further building. The savings would be 
minuscule, IMHO. Assets being implicitly shared, any textures passed 
to another user will link to the same inventory item, so that 
deleting something from one user's inventory doesn't mean that it is 
deleted from all users' inventories. There is no way to determine a 
reference but by scanning all inventories and all object assets.

Melanie

Justin Clark-Casey wrote:
> Melanie wrote:
>> All assets have, at some point, been on a user's inventory. There is 
>> no way to upload anything without having it in inventory at some point.
>> The largest assets are textures, and they will always pass through 
>> user inventories. Also, they will remain in user inventories despite 
>> _also_ being on region objects. Making regions hold their own assets 
>> authoritatively would cause massive data duplication, albeit 
>> distributed, and not really unclutter the central database.
> 
> Assets can be loaded via OAR and other mechanisms that never flow 
through inventory.  Also, I believe it's quite 
> possible to completely delete items from user inventory.
> 
>> 
>> I believe a tag and reap mechanism that slow-scans all assets for 
>> contained assets and all inventories for referencs and tags all 
>> referenced assets, as well as regions transmitting "asset lists" of 
>> assets currently referenced inworld, and the last use flag. Let that 
>> run for 6 months, then reap all unflagged, reset all flags, and 
>> start a new cycle.
>> 
>> This doesn't have to be mutually exclusive, in fact it can be 
>> combined with persistent local asset caching (e.g. local texture 
>> storage for inworld objects) as well as a HG model.
>> 
>> Melanie
>> 
>> Diva Canto wrote:
>>> Diva Canto wrote:
>>>> Justin Clark-Casey wrote:
>>>> 
>>>>> An even more radical solution would be to switch osgrid to a pure 
Hypergrid model.  The osgrid UAI services could still 
>>>>> act as the home services for many people who don't want to run their 
own regions, but the responsibilty for maintaining 
>>>>> region-side assets would shift to other OpenSim instances (and some 
people would also use them for their home services 
>>>>> instead of osgrid).
>>>>>
>>>>> 
>>>>> 
>>>> I've been thinking about this too. I think it should be possible, 
>>>> although we need to rethink a little bit the association between 
users 
>>>> and UGAIM servers. Right now it's sort of bundled; we need to 
unbundle. 
>>>> We could make an interface for the User server that would allow users 
to 
>>>> set their servers.
>>>> 
>>> Actually, we don't even need to change the user base data. The 
inventory 
>>> assets are only a [relatively small?] percentage of all the assets in 
>>> the grid asset server. Most of the assets, I would say, are inworld 
>>> things that aren't on any inventory. They are on the "region's 
>>> inventory" so to speak. So we could move all regions into HG mode, 
>>> setting the proper local servers in their OpenSim.ini's. The users 
>>> inventory would still be OSGrid's Inventory server.
>>>
>>> Even so, there are a few things that need changing/improving for this 
to 
>>> happen. But it's not that far out.
>>>
>>>
>>>
>>>
>>> 
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>>>
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> 
> 
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