User:Babbage Linden/Office Hours/2008 11 12

Transcript of Babbage Linden's office hours:

[8:16]	Nock Forager:	Hi Babbage fallin
[8:16]	Babbage Linden:	hi everyone
[8:16]	Babbage Linden:	sorry i'm late
[8:16]	Imaze Rhiano:	hi
[8:16]	Fake Fitzgerald:	hi
[8:16]	Babbage Linden:	stuck in a meeting
[8:16]	Babbage Linden:	let me ping the lists
[8:16]	WolfPup Lowenhar:	that is ok
[8:17]	Imaze Rhiano:	Arawn... move bit - let Babbage to sit his throne chair :P
[8:17]	Chaley May:	hi
[8:17]	Arawn Spitteler:	Your heart is mechanical, so you must nly be tardy
[8:18]	WolfPup Lowenhar:	hey sheet
[8:18]	Sheet Spotter:	G'day, eh.
[8:18]	Babbage Linden:	thanks arawn :-)
[8:19]	Babbage Linden:	so, we haven't been working on any specific scripting tasks this week
[8:19]	Babbage Linden:	but there has been more discussion about script limits for open spaces
[8:19]	Babbage Linden:	and we've also been talking about embedding mono in the viewer for scripting
[8:20]	Babbage Linden:	and we've built a proof of concept viewer which embeds mono and iron python
[8:20]	Babbage Linden:	which has been interesting
[8:20]	Babbage Linden:	we've got a meeting at 9 to talk about whether we want to take that forward
[8:20]	Babbage Linden:	the initial goal will be to use it for automating testing
[8:21]	Babbage Linden:	but ultimately it would be nice if we could also use it for resident scripting
[8:21]	Chaley May:	err it dont work like that
[8:21]	Chaley May:	oops wrong chat
[8:21]	Sheet Spotter:	Are there any plans to show an AV the scripting impact they have on a sim?
[8:21]	Joshewa Daniels:	we need a way to get useable websites on prims interactive abilitys, i know it will work i have seen it in other 3d world games
[8:21]	Babbage Linden:	sheet, good question
[8:21]	WolfPup Lowenhar:	that is already built into the virewer
[8:22]	Sheet Spotter:	Similar to Avatar Rendering Cost, but focussed on the load their scripts are creating.
[8:22]	Babbage Linden:	for the script limits work, we're creating parcel and avatar pools for script resources
[8:22]	Joshewa Daniels:	really need better parcel prim limits as well
[8:22]	Joshewa Daniels:	thats something that has been needed for a long time
[8:23]	Joshewa Daniels:	and i know 98% of all us members would agree
[8:23]	Babbage Linden:	there will be ll* library calls for scripts to find out the used and available script resources in the current pool
[8:23]	WolfPup Lowenhar:	kewl
[8:23]	Babbage Linden:	so you will be able to attach and object which could tell you how many script resources in your pool are being used
[8:23]	Babbage Linden:	and are available
[8:23]	Babbage Linden:	we are also talking about making that visible in the ui
[8:24]	Sheet Spotter:	Awesome.
[8:24]	Babbage Linden:	but there's lots of work being done on the ui
[8:24]	Sheet Spotter:	Most AVs are not aware of the impact they have.
[8:24]	Babbage Linden:	so i'd prefer not to add more ui complexity where there are lots of people try to remove complexity
[8:24]	Sheet Spotter:	If they were aware, they might moderate their impact.
[8:24]	Babbage Linden:	yes, i agree
[8:24]	WolfPup Lowenhar:	that would help builders out cause then they could better script there items to use less of the pool
[8:24]	Babbage Linden:	making people aware of their impact would help
[8:25]	Babbage Linden:	we are likely to first expose script resource usage
[8:25]	Nock Forager:	What "resources" parameters will be shown?
[8:25]	Babbage Linden:	then work on determining reasonable limits
[8:25]	Babbage Linden:	based on both the current script usage
[8:25]	Babbage Linden:	and the script usage we can support on various configurations
[8:26]	Babbage Linden:	full regions get around 800MB of memory for example
[8:26]	Babbage Linden:	for scripts, physics, updates, texture transfers and everything else
[8:26]	Babbage Linden:	open spaces end up with far less memory
[8:26]	WolfPup Lowenhar:	im alwas wondering how big an impact im having on regions with my builds
[8:26]	Babbage Linden:	as there are 16 sharing the same host
[8:26]	Myla Moody:	when you say "script usage", are you speaking of memory use, instructions per second, events, etc? :)
[8:26]	Babbage Linden:	i'm mostly talking about memory in the first instance
[8:27]	Babbage Linden:	the biggest performance problem we have is when simulator processes grow and make the host swap
[8:27]	Babbage Linden:	so the first resource we'll look at is memory
[8:27]	Babbage Linden:	CPU is somewhat self limiting
[8:27]	Babbage Linden:	in that we give scripts a certain number of ms to run per frame
[8:27]	Babbage Linden:	if all the scripts aren't run, they are run next frame
[8:28]	Babbage Linden:	so, running many scripts that use lots of CPU
[8:28]	Babbage Linden:	makes the scripts slow down
[8:28]	Babbage Linden:	but shouldn't make the sim slow down
[8:28]	Babbage Linden:	whereas many scripts causing the host to swap
[8:28]	Sheet Spotter:	Are sims allocated to servers based on their historical memory usage? Can low usage sims be paired with high usage sims?
[8:28]	Babbage Linden:	will slow the entire region down
[8:28]	Babbage Linden:	and all the other regions on that host
[8:29]	Babbage Linden:	sims are allocated based on the software installed on hosts
[8:29]	Babbage Linden:	so, if you've used the preview grid
[8:29]	Babbage Linden:	you may have noticed that you get "this simulator is running a different version" message
[8:29]	Babbage Linden:	where we have hetrogenous grids
[8:29]	Babbage Linden:	ie grids where different hosts have different software
[8:29]	Sheet Spotter:	That message also appears on the main grid, during rolling upates.
[8:29]	Babbage Linden:	het grid has been a massive success for us
[8:30]	Babbage Linden:	it allows us to do rolling restarts
[8:30]	Babbage Linden:	and test multiple versions of second life
[8:30]	Babbage Linden:	at the same time
[8:30]	Arawn Spitteler:	Before Het Grid, we'd be closed right now.
[8:30]	Babbage Linden:	when hosts start up
[8:30]	Babbage Linden:	they find regions that should be running on the software that the host has installed
[8:31]	Babbage Linden:	so, we don't use load to determine where regions get run
[8:31]	Babbage Linden:	we use the region's channel
[8:31]	Babbage Linden:	and find a host with that channel's software
[8:31]	Babbage Linden:	the biggest problem with the memory bloat due to scripts
[8:31]	Babbage Linden:	is that one heavily scripted region
[8:32]	Sheet Spotter:	Without that assessment, all the high memory usage sims could be placed on one server; all the low usage on another.
[8:32]	WolfPup Lowenhar:	that is an interesting approach
[8:32]	Babbage Linden:	can affect the performance of lightly loaded regions
[8:32]	Babbage Linden:	and when regions swap hosts due to restarts
[8:32]	Babbage Linden:	a region that ran ok last week
[8:32]	Babbage Linden:	might struggle this week
[8:32]	Babbage Linden:	when we have resource limits
[8:32]	Babbage Linden:	the performance should be more predictable
[8:32]	Sheet Spotter:	Cool.
[8:33]	WolfPup Lowenhar:	that makes since
[8:33]	Babbage Linden:	no combinations of regions should cause bad performance
[8:33]	Sheet Spotter:	Will the limits trigger a throttle?
[8:33]	Babbage Linden:	the limits will work like prim limits
[8:33]	Sheet Spotter:	A progressive throttle.
[8:33]	WolfPup Lowenhar:	and that would improve the overall SL experience
[8:33]	Babbage Linden:	so we don't add yet another rationing system
[8:34]	Babbage Linden:	if there isn't enough memory availabe
[8:34]	Babbage Linden:	an object won't rez
[8:34]	Babbage Linden:	just as if there isn't enough prims for it
[8:34]	WolfPup Lowenhar:	i know thee are some places that no mater what when you go there you get hit with so much lagg it is horiable
[8:34]	Myla Moody:	how would scripted attachments be handled in such a case?
[8:34]	Babbage Linden:	myla, scripted attachments would use the avatar resource pool
[8:34]	Myla Moody:	ahh
[8:34]	Babbage Linden:	which is a constant size
[8:34]	Babbage Linden:	so that if you attach a bunch of scripts
[8:35]	Babbage Linden:	you will be able to teleport anywhere
[8:35]	Imaze Rhiano:	how is script initial memory usage decided? like classic lsl initial memory 16K - mono - initial memory usage 64k?
[8:35]	Babbage Linden:	without being told that resources are available
[8:35]	Babbage Linden:	imaze, LSO scripts will still be 16KB always
[8:35]	Babbage Linden:	if there is 16KB available, an LSL script will rez
[8:35]	Babbage Linden:	with Mono scripts, we'll probably use the same mechanism initially
[8:36]	Babbage Linden:	check to see whether there is 64KB availabe
[8:36]	Babbage Linden:	allow the rez to happen if there is
[8:36]	Babbage Linden:	but, in future
[8:36]	Nock Forager:	Currently, do you have in your mind what the memory limit should be?
[8:36]	Babbage Linden:	we would be able to have Mono scripts request memory
[8:36]	Babbage Linden:	so they might say I need 2KB
[8:36]	Babbage Linden:	and be able to rez whenever there is 2KB availabe
[8:36]	Babbage Linden:	on the other hand, they might say that they want 2MB
[8:37]	Babbage Linden:	and then be able to use much more memory than scripts can currently use
[8:37]	Babbage Linden:	without having to break the script up in to tiny parts
[8:37]	Sheet Spotter:	If the attachment limit is per avatar (i.e., not sim-specific), then high numbers of avatars could impact a sim.
[8:37]	Imaze Rhiano:	if mono's initial memory is going to be 64k then many script are going to stay in orginal LSL. At least those small one.
[8:38]	Babbage Linden:	until we allow Mono scripts to request less, yes
[8:39]	Nock Forager:	perhaps region owner should maintain that's limit maybe? Sheet.
[8:39]	Sheet Spotter:	Or some combination. The region owner could adjust the limit?
[8:39]	WolfPup Lowenhar:	but how can we determine whis would be better for a certin type of script?
[8:39]	WolfPup Lowenhar:	as builders
[8:39]	Babbage Linden:	we haven't talked about region owner adjustments yet
[8:40]	Babbage Linden:	i know there are prim bonus settings for prims
[8:40]	Imaze Rhiano:	wolfpup... initially for simple script LSL would be better - until Mono can request less memory
[8:40]	Sheet Spotter:	The region owner can adjust the max number of AVs.
[8:40]	Sheet Spotter:	That might be a crude proxy for limit the number of AV scripts.
[8:41]	WolfPup Lowenhar:	that is true sheet
[8:41]	flopsie McArdle:	hi everyone
[8:41]	Babbage Linden:	open spaces will likely have script limits first
[8:42]	WolfPup Lowenhar:	and then the regio owner when he parcels the the regein he could set how many AV's on a particular parcel
[8:42]	Myla Moody:	if the resource limits would initially consider all mono scripts to consume the full 64k memory, my concern is how it would affect multi-use avatar attachments which may contain 30-40 scripts. would these be an issue?
[8:42]	Myla Moody:	assuming those 30-40 scripts compile and work fine as non-mono, within the old 16k memory limits
[8:43]	WolfPup Lowenhar:	mayla babbage said that region and av pools are seperate
[8:43]	Myla Moody:	yes, i heard :)
[8:43]	Sheet Spotter:	In a heavily populated sim I would be concerned about the impact an AV with 30+ scripts in their attachments has on those around them.
[8:43]	Imaze Rhiano:	Myla... that would likely mean that only option would be use classic LSL until Mono can decide it's memory usage
[8:43]	Obi Woebegone:	is there a protocol for questions here?
[8:44]	Babbage Linden:	obi, yes, ask them :-)
[8:44]	Babbage Linden tries to keep up
[8:44]	Juls Rosca grins
[8:44]	WolfPup Lowenhar:	so their might be a limit of how many script would be availabe for say tinting windows and such in the region but the av's would have a different limit
[8:44]	Obi Woebegone:	I have an issue with physics here... I was hoping to apply forces from several places on a linked object (from child prims) but the results i'm getting are pretty unpredictable
[8:44]	Babbage Linden:	sheet, an av with 30-40 scripts on them wouldn't have an effect unless everyone had that many scripts and the region itself had many scripts
[8:45]	Arawn Spitteler asks, and might be heard: AD Scripting is something I'd think of, but would placing the scripting load where it belongs cost too much on the communications channels.
[8:45]	Babbage Linden:	only when the combined script memory usage makes the sim swap does it become an issue
[8:45]	Babbage Linden:	our next job is to work out good settings for the limits
[8:45]	Sheet Spotter <-- works and plays on heavily scripted sims with multiple heavily scripted AVs. :-)
[8:45]	Obi Woebegone:	It seems that only one force and one torque is considered for the entire object - but there is clearly room in the havok engine for forces to be applied locally from all around the object...
[8:46]	WolfPup Lowenhar:	< work the same place sheet dose :)
[8:46]	Nock Forager:	People may say "more!" if you choose any limit size :)
[8:46]	Obi Woebegone:	one could work around this if it was possible to apply a torque to an arbitrary point but I don't see a way to do that... does this make sense?
[8:46]	Babbage Linden:	nock, yes people will say more
[8:47]	Babbage Linden:	we're going from "unlimited" to "some limit"
[8:47]	Babbage Linden:	but we're doing it to avoid the tragedy of the commons
[8:47]	Babbage Linden:	currently, in some places, everyone over uses the simulators resources
[8:47]	Babbage Linden:	and so everyone suffers
[8:48]	Babbage Linden:	but there is also an upside
[8:48]	Babbage Linden:	we're going from arbitrary 16KB or 64KB limits per script
[8:48]	Imaze Rhiano:	so it is decided that limit comes? it is not anymore just talk?
[8:48]	Babbage Linden:	to script sizes only limited by the resources available in the parcel
[8:48]	Babbage Linden:	or avatar pool
[8:48]	Babbage Linden:	imaze, no this is still being discussed
[8:48]	Babbage Linden:	no final decisions have been made
[8:48]	Babbage Linden:	but it's looking likely
[8:49]	Chaley May:	if you create limits so people get their fair share of the sims server then you can increase prims :)
[8:49]	Myla Moody:	purely curiosity question, has anyone toyed with a timeline for beta deployment yet? :)
[8:49]	WolfPup Lowenhar:	well having the limits is understandable
[8:49]	Babbage Linden:	chaley, we could move to some super complicated over-engineered solution which allows people to trade of prims vs scripts vs foo
[8:50]	Babbage Linden:	but i'd really like to come up with something simple that works :-)
[8:50]	WolfPup Lowenhar:	i used to live on a soiim that has a club and a couple of stores and some time the lag there was awful
[8:50]	Babbage Linden:	ok, i need to go to another meeting in 10 minutes
[8:50]	Babbage Linden:	and i need a bio break first
[8:50]	Babbage Linden:	so, we need to wrap up in a minute
[8:50]	Arawn Spitteler:	If scripts are alocated by Parcel, not every parcel is going to be used, so there'd be left over resources, and sim owners could allocate multipliers.
[8:50]	Babbage Linden:	arawn, yes
[8:51]	Imaze Rhiano:	I hope that you will find to set Mono's memory usage to lower - 64K vs 16K will kill mono until it is fixed.
[8:51]	Babbage Linden:	we haven't talked much about that yet, but will do
[8:51]	Babbage Linden:	so, before i go
[8:51]	Babbage Linden:	i'd like to give you all a set of new carbon goggles
[8:51]	Babbage Linden:	i fixed a load of bugs last night
[8:51]	Babbage Linden:	so now it's much more usable
[8:52]	WolfPup Lowenhar:	kewl
[8:52]	Babbage Linden:	and it's open source so you have have a look and play with it
[8:52]	Babbage Linden:	to come up with lots of interesting augmented virtual reality applications in SL
[8:52]	Babbage Linden:	there you go
[8:53]	Babbage Linden:	it's set for sale for 0L$
[8:53]	Myla Moody:	thank you :)
[8:53]	Babbage Linden:	there's also a Carbon Goggles group you can join if you'd like updates
[8:53]	WolfPup Lowenhar:	thx
[8:53]	Sheet Spotter:	Thank you for this time, Babbage. Always interesting to see how the gears are turning within LL. :-)
[8:53]	flopsie McArdle:	thanks babbage
[8:53]	Babbage Linden:	let me know if you build anything interesting with it :-)
[8:54]	Imaze Rhiano:	thanks Babbage
[8:54]	Chaley May:	thanx
[8:54]	Babbage Linden:	and I'll be looking at http://carbongoggles.org to see if you annotate any objects
[8:54]	Chaley May:	still not sure what it is i have to read it
[8:54]	Chaley May:	i thought my avatar would be wearing goggles
[8:54]	Babbage Linden:	there's more information here: http://jimpurbrick.com/2008/07/01/collaborative-user-generated-ambient-augmented-virtual-reality-visualisation-size-denmark/
[8:55]	Babbage Linden:	ok, now i need to go
[8:55]	Babbage Linden:	thanks for coming everyone
[8:55]	Chaley May:	bye
[8:55]	Myla Moody:	have a great day :)
[8:55]	White Platini waves
[8:55]	Nock Forager:	Thanks for the meeting Babbage
[8:55]	flopsie McArdle:	bye babbage
[8:55]	Juls Rosca waves
[8:56]	Babbage Linden:	bye!