Under the grid: Calling cards
by Tateru Nino 
Apr 30th 2008 at 1:00AM
Filed under: Game mechanics, Second Life
Welcome to the eighth installment of "Under The Grid", an irregular look at the mechanics underneath Second Life. Last time we looked at Mono. This time, we're taking a quick look at part of the presence system, specifically: Calling cards.
You see, calling cards are a part of the system few people give much thought to, but can really represent a severe drain on your in-world performance.
You can obtain calling cards in one of two ways. Either someone gives you one, or there is an automatic exchange of cards when someone sends you a friend invitation, and you accept.
Calling cards can be copied, put in assorted folders, and those folders used for ad-hoc group IMs. Unlike other objects, they can't be transferred to other people or put in the inventory of an object.
The problem with calling cards is that they have two states: Online and offline -- and that this state is stored with the card in the viewer's copy of it in your inventory.
As people log into and out of Second Life, the presence system automatically sends out notifications to people who are their friends, and to people who have their calling card. That's where we run into problems.
You see, every time one of the people whose calling card you have logs in or out, the system sends you a notification. It may not be a popup (they might not be a friend, or you might have those notifications suppressed) but there's still extra work going on.
The viewer has to then search through every item in your inventory, and check to see if it is (a) a calling card, and (b) if it is the calling card of the person that it has received a login/logout notification for. If it is, it updates the status of that card. You might have more than one card for a given person, and they could be in pretty much any of your inventory folders, so a complete search is needed.
The larger your inventory is, the more work each update takes. The more calling cards you have, the more updates you get.
Ever have those situations where your viewer seems to freeze for half a second? A second? Possibly several seconds? And they happen just here and there? That's probably your viewer grubbing its way through your overly large inventory trying to update your calling cards.
There are certainly ways that this could be improved, but right now calling cards represent an invisible drain on your viewer resources, and one that you should be aware of.
Reader Comments (Page 1 of 1)
Jacek Antonelli said on 1:11AM 4-30-2008
I can feel a disturbance in the Grid... as if millions of year-old callings cards for people you can't even remember, suddenly cried out in terror... and then... were deleted.
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Peter Stindberg said on 2:55AM 4-30-2008
See JIRA issue VWR-3800:
http://jira.secondlife.com/browse/VWR-3800
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Jay said on 5:20AM 4-30-2008
Hmm, I deleted all mine about a month ago, 18 months of collecting them. My inventory was significantly lighter afterwards.
These are one thing, along with landmarks, that need an overhaul (and yes I know that letter on SLDev shows that landmarks are being looked at for a revamp)
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Uccello Poultry said on 9:49AM 4-30-2008
hmmm .. might be a good time to write all the names from my Calling Card collection on a notecard and dump the actual (actual-virtual?) cards. Thanks for the info!
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Dedric Mauriac said on 12:34PM 4-30-2008
I hadn't even given this a thought. I've been accepting friend requests from everyone and have built up a pretty large list. Now it seems I have to do some social cleansing ...
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Nock Forager said on 1:40AM 5-02-2008
I tought the state update is on-demand, but it's not!? Everytime state changed the cards send thier satus? ough.
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Cyn said on 1:37PM 5-03-2008
Interesting. I did some playing around with them today; looks like once you have the calling card (and the friend) they each function independently of the other. I can delete calling cards for friends, and I'm still friends, and I can remove a friend, and the calling card stays.
I remember a few months back when Mr. Shang said he'd had to axe his friends list because all the updating of their status was causing him to crash and hang and crash and hang, and the only solution was removing several hundred of them. I wonder if simply removing all the calling cards would have worked instead?
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Krissy said on 4:00PM 5-03-2008
@Jay - Did you notice a difference in client performance after you deleted the calling cards?
@Uccello - I agree, I think I shall take print screens of the names (for whatever reason) and delete them!
Thanks Tateru!
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Ghosty Kips said on 3:08PM 7-25-2008
If the system is sending me a notification, it must already know I have a calling card - else, *everyone* that logs in or out of SL is causing the system to send updates to *everyone* in the hopes they have a card!
If the system works as you've described it, deleting the cards has no effect anyway. Since you say the system searches through my entire inventory for the card, it obviously doesn't know that I have it ot not. I'm probably still going to get the notifications, card in inventory or no.
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