Cache in hand

Apologies in advance for extreme geekism in this post – if you’re not at all technically minded, you might want to skip to the end and just pretend you’ve read the lot; you can always just look at the pictures – I won’t mind, i promise – failing that, grab an early mince pie and a coffee and pop across to the library for a bit… all the techie stuff will be over by the time you come back!

In a gentler age, before computers had become commonplace, a cache was somewhere that squirrels hid their nuts in preparation for the long winter ahead… oh, i how long to return to those less stressful days! (Guess who was brought up on Enid Blyton’s Uncle Merry!).

Anyway, i digress – nowadays, the IT crowd has stolen the cache for their own nefarious use and turned it into a digital repository – a handy place to keep all your frequently used bits and bytes – think of it as a kind of spice rack: all your most-used condiments; Basil, Rosemary and pepper, handily within reach, right next to the hob; whilst those less frequently used, the black onion seed, galangal and mace, hide away at the back of the cupboard, (behind that strange bottle of marinade you bought on a whim in a Moroccan market).

That’s exactly how sl operates its cache: As you wander around the virtual world, all the textures, objects, co-ordinates and various other bits and bobs that go to make up the world we see around us are downloaded into our cache, so that next time we visit, rather than all our computery whizzy-electro-trons having to trek all the way to the States and back again, a quick visit to your hard disk is all that’s required. (Of course if you live in the States, and happen to be next door to a sl datacentre, you might not want a cache at all – let Linden Lab shoulder the burden – unless you have a totally rubbish connection!). This means familiar and regularly visited places will rez nice and quickly and those big shops, with lots of products on display that we’ve never been to before, (and will not therefore be cached), will take forever to resolve into something more recognisable than a grey maze of shapes. Our inventories are also squirreled away in our cache – (although non-prim clothing textures are kept on the Linden asset servers – don’t ask why, it’s just one of the arcane mysteries of sl).

The cache is slightly magical, which is why clearing our cache will often fix intractable problems that nothing else will shift – a bit like flushing a big jobbie away down the loo, followed by frenzied activity with the toilet brush and copious squirtings of Domestos. The only trouble with this approach is that you flush away all the useful stuff too, so it’s only recommended when nothing else will work – clearing the cache on a regular basis slows sl down for you and uses a heck of a lot more bandwidth than simply leaving it alone.

Well done if you’ve persevered this far – i’m afraid it’s going to get rather more geeky from this point on!

Frontier trading post

You may remember my recent inventory disaster (i certainly do!), when i managed to delete half my worldly goods – well, i haven’t given up on trying to retrieve them just yet – although i think i’m probably flogging a dead horse. i had a cunning plan, based around something that not a lot of people may know… On the main Grid – Agni – our assets, that is everything that makes us who we are; all our belongings and all our personal effects, are refreshed on a fairly frequent basis. However, over on the Beta Grid – Aditi – things are a bit more anarchic, (it’s one of the things i like about Aditi; it’s a bit like a frontier town… edgy and lawless, and people fight in the street. i guess i’m a bit of a closet anarchist at heart). They don’t care over there, so assets are hardly ever refreshed – usually only when a major revision of software is being tested, like mesh. In practical terms, what this means is that, provided you don’t mess around with it, the contents of your inventory on Aditi, stays pretty much in pristine condition for a long, long time – no matter how much you change it on Agni. So, theoretically, if you clear your cache before logging into Aditi, your inv. will be re-built from the Aditi asset set when you rez – and it’s likely this will be a much older asset set than you had on Agni, (still with me?)

Anarchic garden centre

Well, it turns out that the theory works – it did for me anyway. Unfortunately, it’s not going to solve the problem of my missing items – the Aditi and Agni asset sets are entities in their own right, they’re not shared – so, even though all my missing items might be in my inv. on Aditi, they won’t be there when i log back in to Agni 😦  Nor can i send transferable items to myself across Grids and, since neither Grid has any commonality with the other, (unless anyone out there knows differently), i can’t simply drop a pile of objects on the floor in Aditi, log into Agni at the same place and pick them up again, more’s the pity! Those lovely Linden chappies do have the power to copy items between Grids, but you’ve more chance of finding a full set of hen’s teeth than persuading them to do it on an individual basis.

What’s the point then? Well, there’s a few useful things i’ve gleaned from the exercise… first, i know my items still exist ‘somewhere’ – this would be extraordinarily useful if i’d accidentally deleted a pile of my own creations: It would be a simple matter to rez them on Aditi, export them into XML files and import them back into Agni as linksets, which is useful to know for when i inevitably manage to do such a stupid thing in the future – sadly, I can’t do this with items for which i’m not the creator.

Erm... Teddy bear anarchy?

Second, at least i now know exactly what i’ve lost – since a lot of the items have LMs, i now have a reminder of where they came from and, even without these, i can look up their creators and search for them inworld and on the marketplace. It won’t help me with purchases from stores that are now closed, but it sure makes replacing some of those treasured items a lot easier.

Finally, it leaves me with the barest shred of hope that, maybe, somehow it might not be beyond the bounds of possibility that there’s still a chance of recovery… never say die, eh?

All this fiddling has, of course completely confused sl – back on the Main Grid, i now have an apparent inv. of over 10,000 items, even though there’s really only 8,000 in there. i have a sneaky feeling that the extras are Aditi assets indexed in my cache but which therefore, can’t be found on Agni – it’s sort of comforting to know that my missing things are there, it’s just a shame i can’t get to them!

Gosh, you lot are suckers for punishment – i can’t believe you’ve hung on this long! Fair enough… i’ll warn you now, what follows is extreme geekism – not for the faint-hearted!

From what you’ve seen above, the advantages of a large cache are immediately apparent – the more of sl that you can store locally, the faster and better performance will be inworld. Only one problem with that, the Lindens limit us to a 1GB cache. However, if you’re using Phoenix or Firestorm, (may work with other viewers too, but i haven’t played with them to find out), you can expand your cache to whatever size you want – so if you’ve got a spare 1 or 2TB hard drive knocking around and you fancy a mega-cache, read on!

You’ll need to set up a local texture cache, using a caching server called Squid. However, before Squid will run, you’ll need to also be running Perl on your machine – some operating systems already have it; Windows doesn’t, (you can get it for Windows here – make sure you get the right one, if you have a 64-bit machine!). Install Perl – you’ll have to be comfortable working from the command prompt to do this… if you’re not, you should probably quit now! Install Squid and configure it, then set up Phoenix/Firestorm to use a proxy cache in your viewer’s preferences. You can find out how to do that and configure Squid here – at which point, i suggest you nod sagely, wander off to make some toast and marmite, and a nice cup of tea, by which time you’ll have forgotten all about it and can carry on as normal!

Seriously though, if anyone has implemented Squid and found it to be beneficial, let me know, so i can decide whether it’s worth committing any more of my precious hard disk space to sl.

Wow! It’s been quite a wordy entry and probably way too techie for a blog of this sort… sorry, it just slips out occasionally! Before i disappear and grab myself a quick glass of perspective and normality, if there is anyone out there who knows of a way i can move inventory from Aditi to Agni (Oz Linden, are you reading this?), please, please, please let me know! And if anyone has been a plonker like me recently and perma-deleted something they shouldn’t and needs to look it up, or recover their own deleted creations and import them back inworld, drop me an IM or notecard and i’ll be happy to talk you through it.

i think that’s probably more than enough for today… back to something less demanding after the weekend! Have fun folks!

S. x

Write it, cut it, paste it, save it,
Load it, check it, quick – rewrite it,
Plug it, play it, burn it, rip it,
Drag and drop it, zip – unzip it
Daft Punk – Technologic

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3 Responses to Cache in hand

  1. Tristam Cooke says:

    I know this is late, (I’ve been reading Backwards since I found your blog, almost got my computer taken away in class when i read the linden guide) but there is one way i can think of to move your objects over, though it’s pretty sketchy. Being at least an experienced in Second Life, you may have heard of copybotting. I don’t know if it was as big of an issue on MG as opposed to on TG, but, TSL being sort of an unlawed country, so it was rampant! If you don’t know, a copybotter is any underground/contraband viewer that can do things such as the export feature on emerald, but can copy all textures, primitives, clothing (right off the avatar wearing them, no less) and the advanced ones can steal sounds, animations, and some scripts. REGUARDLESS of rights on the object. They are all pulled form your cache and can be re-uploaded with FULL PERMISSIONS. the downside is, someone who knows their way around SL can tell they are copybotted. For one hand, you will be the creator, and if you inspect the item, a dead giveaway is that each primitive was created within milliseconds of each other. Being logged in on one is taboo (not to mention can get you banned), and some can be detected, but they have many practical uses, which is why I made contacts to get them.

    Some copybot viewers have functions to backup your ENTIRE INVENTORY TO YOUR HARD DISK!!! that’s what they were originally made for, but the technology leaked and was quickly abused.

    Anyways, from time to time my friends would start up an OpenSim server, and I always found myself upset at the fact that I was stuck using a awkwardly walking, ugly mullet haired naked chick. (an odd choice for a default avatar, opensim), so I would go to a discreet area in TSL, copy my avatar, and reupload it into opensim. It was a little tricky, considering they didn’t share asset servers(luckily uploading into opensim is free, but It sounds like the ones you want to transfer from one share an Asset server, at least probably for textures. If it’s something uique and REALLY treasures, this may be your only way. It certainly should be okay for objects you own, and im my opinion, you should have full rights to anything you buy in SL, for personal use (within your own person, not giving out to anyone else).

    So, if you have to, this might help, but it could end up sending you to the cornfield for a LONG time. But maybe you could get a copy of the tractor while you’re there!

    • Until sl and my blog become part of the syllabus, i don’t think it’s entirely wise to be reading it in class! 😉

      i’ve heard lot’s of arguments for and against tools to back up your inv., such as Second Inventory and they all have their merits, i don’t think i’ve ever seen a successful argument in favour of copybotting content that isn’t your own exclusive creation – whatever justification anyone can offer for it, and whether we agree with the rules or not is immaterial. Whatever moral stance we take on intellectual property rights has no bearing on it – legally, it’s considered wrong. It’s no different to breaking the speed limit on the motorway in the dead of night when there’s nobody else around – it’s still illegal, it’s still breaking the law and we can still be prosecuted for it, no matter what we might argue as mitigating circumstances.

      Copybotting will earn more than a spell in the cornfield – you could end up with a ban and a DMCA in the real world, costing real money and maybe even a real criminal record!

      All i’m asking for is a server-side inventory back up that LL can roll back to on a per resident basis – that would suit me just fine!

      s. x

      • Tristam Cooke says:

        If LL made Sense, we might have that. Unfortunately for the rest of us, it’s illegal to protect things we own. I can’t be the only one who thinks that’s messed up.

        Like I’ve said before, I am a firm believer that once you purchase something you are entitled to an infinite umber of copies for your own use. SL or otherwise.

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