Simulator User Group/Transcripts/2014.04.22

Simulator_User_Group
Prev 2014.04.15	Next 2014.04.29
== List of Speakers ==
Duckie Dickins 	Inara Pey 	Jenna Felton
Kelly Linden 	Kennylex Luckless	Kitto Flora
Lexbot Sinister	Lucia Nightfire 	Mona Eberhardt
Nalates Urriah 	Oz Linden 	Qie Niangao
Simon Linden 	Talarus Luan 	Tankmaster Finesmith
Whirly Fizzle 	Yuzuru Jewell 	
== Transcript ==
[12:00] Mona Eberhardt: Hi Inara :)
[12:00] Inara Pey: Hi, All
[12:00] Simon Linden: Hello everyone
[12:01] Nalates Urriah: Hi
[12:01] Simon Linden: There's not much news this week for server releases ... nothing was updated today and tomorrow the Magnum RC will get a fix for a minor bug that was introduced
[12:02] Kelly Linden: https://jira.secondlife.com/browse/BUG-5763 is the bug on Magnum getting the update
[12:03] Simon Linden: I am going to have to go AFK to deal with a system issue right now, but I'll try to lurk here
[12:03] Kitto Flora: Is there a known problem with llHTTPRequest() messages being randomly delayed for up to a few minutes?
[12:03] Kelly Linden: Kitto: no, none that I'm aware of.
[12:04] Kelly Linden: Kitto: There are a few different queuing systems around various curl usages in the simulator though - it is possible to see significant delays if there are a *lot* of requests in flight.
[12:04] Kelly Linden: I'd expect the load that might cause minutes worth of delay to be huge
[12:06] Kitto Flora: The GSLRailway car position is mapped by the car sending a llHTTPRequest() POST message every couple of seconds as it moves through the sims. The receiver is located in Periwinkle. Received messages are randomly delayed buy up to a minute or two. This has started happening in the last week, afaik.
[12:07] Kelly Linden: Hrm.
[12:07] Jenna Felton: is there a way for not estate manager to detect how many URLs are used in the sim?
[12:07] Kelly Linden: If you have a reproducible case a jira would be helpful.
[12:08] Lucia Nightfire: I wish there was a way to detect an object's net timing and/or url usage in some manner, heh
[12:08] Kelly Linden: About Land: Script Info I think returns summary data (at the top) to everyone.
[12:08] Lucia Nightfire: or a way to detect an owner's total url or net timing usage
[12:09] Jenna Felton: true, for the parcell i can see that :)
[12:09] Lucia Nightfire: I mean rezzed objects as well
[12:09] Oz Linden: what problem are you trying to solve, Lucy?
[12:09] Kitto Flora: I would have to build test objects for someone else to work on the llHTTPRequest() message delay problem. The Railway system itself is complex.
[12:10] Lucia Nightfire: where a majority of a region's net timing is coming from
[12:10] Lucia Nightfire: if its rezzed objects, attached objects or an agent's viewer connect as well
[12:10] Lucia Nightfire: *connection
[12:10] Kitto Flora: The problem is not a disaster, just makes the map indicator jump randomly along the map. Looks bad.
[12:10] Oz Linden: that's not what I meant... I meant why do you want to know?
[12:10] Lucia Nightfire: troubleshooting region performance issues
[12:11] Lucia Nightfire: which I see in some sandboxes
[12:11] Lucia Nightfire: esp casino's
[12:11] Lucia Nightfire: where guest's objects or attachments interfere with the machines
[12:11] Lucia Nightfire: and region stability
[12:12] Oz Linden reflects that getting performance troubleshooting data using scripts that run on the sim you're troubleshooting sounds circular
[12:12] Kelly Linden: There isn't really a way to split up the timing reports in ctrl-shift-1 window to that level.
[12:12] Lucia Nightfire: I wasn't sure if there was Kelly, it was wishful thinking initially, heh
[12:14] Kitto Flora: If you think that visitor's attached scripts are affecting sim's performance, use the available script functions to read Avatar's script usage, warn and eject those who are excessive.
[12:14] Lucia Nightfire: I have a theory that guests with poor connections or corrupted caches are causing excessive net timing
[12:15] Lucia Nightfire: and it only take one of them to cause an influx
[12:15] Lucia Nightfire: I just don't have teh tools to isolate such a claim
[12:16] Whirly Fizzle: Hmm Ive often wondered how avatars with very low or very high max bandwidth setting affects the region.
[12:16] Kitto Flora: Theres a listed 'drop packet' test in Advanced menu, does that do anything useful for you?
[12:17] Tankmaster Finesmith: no
[12:17] Whirly Fizzle: You can cause the viewer to throttle down max bandwidth if you hit drop packet a lot of times. You can see the throttle happen in the logs
[12:17] Kelly Linden: Working off that debug option, it wouldn't be too hard to make a viewer that faked a lossy connection.
[12:17] Lexbot Sinister: how low would you say low is?
[12:21] Duckie Dickins: It got quiet....I think they lindens might be debugging the coffee maker......lack of caffeine brings coding to a halt.....
[12:21] Whirly Fizzle: hehe
[12:22] Kelly Linden: :) The table is open if you have some topics.
[12:22] Lexbot Sinister: i've been told 500 for max bandwidth is pretty low. it does seem to help me with an unstabile connection though (i got fast but unreliable wifi) and it doesn't appear like i'm affecting the sims im in.
[12:23] Tankmaster Finesmith: hows the group chat lag improvement fix coming along?
[12:23] Kelly Linden: a low bandwidth setting shouldn't adversely affect simulator performance
[12:23] Whirly Fizzle: What about if the avi has lots of packetloss Kelly? Would that adversly affect the region?
[12:23] Mona Eberhardt: I think it frees up bandwidth for other apps that are running simultaneously with SL.
[12:23] Kelly Linden: tankmaster: working out some kinks this morning.
[12:24] Tankmaster Finesmith: we recommend 500 for a wifi connection, lex
[12:24] Tankmaster Finesmith: good to hear, simon
[12:24] Oz Linden: turning max bandwidth down should help with lost packet issues, especially http connections being throttled due to contention with the udp traffic (because it slows down the udp)
[12:24] Kelly Linden: whirly: it is possible, but I don't think we've really seen it be a problem before.
[12:24] Lexbot Sinister: can't complain, works like a charm for me.
[12:25] Kelly Linden: The bandwidth limit in the viewer only applies to UDP data already, which is the most adversely affected by lossy connections
[12:26] Nalates Urriah: Oz, does the viewer detect dropped UDP and throttle the HTTP?
[12:27] Oz Linden: I don't think so, Nal... not explicitly
[12:27] Kitto Flora: A high-load Avatar's effect on a Sim depends on how loaded the Sim is. If the sim has some 'Spare Time' then a high load Av arriving may have little effect. If the Sim has zero spare time then the Av has niticeable effect. Point is - you must check the effect of Av changes in a sim that has a stable and high load.
[12:27] Tankmaster Finesmith: HTTP should throttle itself if its adhering to the protocol correctly
[12:27] Whirly Fizzle: High load as in high script load or high render laod?
[12:27] Whirly Fizzle: *load
[12:27] Nalates Urriah: HTTP Protocol is evaluating UDP packet fails?
[12:28] Tankmaster Finesmith: http and udp are 2 different protocols
[12:28] Kitto Flora: Script and physics load - thats Server(sim) side. Render load problems are in Clients.
[12:28] Oz Linden: but UDP has no congestion control... without the throttle, it would send arbitrarily large numbers of packets, which would increase loss at the weakest point in the path between viewer and sim. That loss would include HTTP packets, and the TCP congestion control under HTTP would then throttle those connections (a lot)
[12:28] Kitto Flora: (Sims do not render)
[12:28] Nalates Urriah: I know that is why HTTP slowing for UDP confuses me...
[12:29] Tankmaster Finesmith: thats not what we are saying, nal
[12:29] Nalates Urriah: Thx, OZ. Now I get it.
[12:29] Nalates Urriah: hx too Tank
[12:30] Tankmaster Finesmith: the http protocol has built into it congestion handling and will slow down on its own w/o any interaction from the program
[12:30] Tankmaster Finesmith: UDP is faster do to a lot le3ss overhead, but it also doesnt have any means of detecting when things are going wrong
[12:30] Oz Linden: see http://en.wikipedia.org/wiki/Network_congestion#Congestive_collapse
[12:31] Nalates Urriah: thx
[12:31] Tankmaster Finesmith: UDP doesnt even know if the host its sending data to is still there or not :P
[12:32] Talarus Luan: More to the point, it doesn't care. :P
[12:32] Whirly Fizzle: Hmm so if a user is getting bad packetloss so the throttle kicks in, is it the region/server doing thr throttling or the viewer? I wish I understood better how that all works.
[12:32] Tankmaster Finesmith: i believe either side can tell the other to throttle udp
[12:33] Nalates Urriah: I get that the slowing happens in the network layer. So, it could be either or both.
[12:33] Oz Linden: for the HTTP traffic, it's transport layer (TCP), and the congestion control operates independently in either direction
[12:34] Oz Linden: (as long as the required ACKs are getting through)
[12:34] Tankmaster Finesmith: udp is ideal for some situations, and http is more ideal in others
[12:34] Talarus Luan: TCP.. http is a protocol on top of either UDP or TCP
[12:35] Oz Linden: we use it only over TCP
[12:35] Talarus Luan: Right. Point is, different layer
[12:35] Oz Linden: (HTTP over UDP is a silly hack)
[12:35] Kitto Flora wants sctp
[12:36] Nalates Urriah: The basic take away is turning down max bandwidth on UDP may reduce lost packets.
[12:36] Nalates Urriah: ?
[12:36] Tankmaster Finesmith: in cases where if a packet is lost or corrupted, and that by the time that packet were resent it's info would be useless do to being out of date, udp is more ideal. for instance, agent updates. If a person is moving around, and the server is sending the viewer the agent's new location, if that packet is lost, by the time its resent the server would have already sent out a update for the next location point and therefor it wouldnt use any previous packets.
[12:36] Tankmaster Finesmith: yes, nal
[12:37] Nalates Urriah: Good explanation Tank, thx again
[12:38] Kitto Flora: Is not terse-update sent 'unreliable' ?
[12:38] Tankmaster Finesmith: in cases where a packet is needed, but its fastest timing isnt so relivent, like information for a texture or object info, then HTTP is preferred as getting reliable info is more important.
[12:39] Lucia Nightfire: hoe are those exp perms coming along, heh
[12:39] Lucia Nightfire: *how
[12:40] Kelly Linden: No updates this week Lucy, but progress is being made. :)
[12:40] Lucia Nightfire: when did that project start btw?
[12:40] Kelly Linden: I'm not sure.
[12:40] Talarus Luan: 2009ish?
[12:40] Nalates Urriah: About the time Linden Realms was released, almost a couple of yers, I think.
[12:41] Qie Niangao: "project" is such a limited term. "crusade" perhaps.
[12:41] Lucia Nightfire: saga
[12:42] Qie Niangao: more saga than Sega, anyway
[12:42] Nalates Urriah: March 2012+/-
[12:43] Oz Linden will be right back
[12:44] Talarus Luan: yay.. client crash.
[12:44] Qie Niangao: welcome back, Tal. You got all the action items.
[12:44] Talarus Luan: Action items?
[12:44] Object: Hello, Avatar!
[12:45] Qie Niangao: 1. Fix client, 2. ..., 3. Profit!
[12:45] Oz Linden: test worked :-)
[12:46] Talarus Luan: Oh. Yeah. That always seems to be the case. :)
[12:47] Oz Linden: I expect to have a Project viewer out soon (hopefully this week, possibly early next) that will include the viewer reading LSL syntax & help from the simulator... would love to get people testing that
[12:47] Talarus Luan: Was funny.. client required me to update earlier, so I said "OK, do it". It downloaded, "installed", and restarted, and asked me to update .. again. O.o
[12:47] Kitto Flora: Its got the Adobe/Flash Player bug :)
[12:47] Talarus Luan: Had to manually download and install it to get it to install properly.
[12:48] Oz Linden: do you have it installed in a non-standard location?
[12:48] Talarus Luan: Define "non-standard"
[12:48] Oz Linden: not the default
[12:48] Whirly Fizzle: If you let it automatically install it just installs to the location of the last V3 viewer you installed. That drives me slightly bonkers
[12:48] Talarus Luan: Of course
[12:48] Talarus Luan: I only have one install
[12:49] Oz Linden: you may have just been unlucky
[12:49] Talarus Luan: Now it can't find itself anymore unless manually installed?
[12:49] Oz Linden: what viewer version do you have now (all 4 numbers)?
[12:49] Talarus Luan: Second Life 3.7.6 (289164) Apr 16 2014 15:15:22 (Second Life Release)
[12:50] Nalates Urriah: Or Talarus is using an old shortcut...
[12:50] Talarus Luan: I checked every shortcut I had. All were the same
[12:50] Oz Linden: that's the current default.
[12:51] Talarus Luan: Anyway.. not wanting to turn this into a client support issue. Just thought it was interesting
[12:51] Talarus Luan: The crashes don't appear to be abated much, though.
[12:51] Oz Linden: there are ways that we expect to have that happen if you're timing is especially bad, but we'd have to have the sequence of versions to figure out if yours was one of those cases. They should be very rare
[12:53] Talarus Luan: Any news on interest-list updates?
[12:54] Oz Linden: that viewer will, like other candidates, get an update shortly ... it's been looking good in the most recent iterations
[12:56] Kennylex Luckless: Meeting soon over, I think I go to Cirano and drive bumper cars :-)
[12:56] Seewo (siwo): seeing Rex isn't in here today, does it mean there is no chat log this time?
[12:56] Lucia Nightfire: CRAP
[12:56] Lucia Nightfire: lol
[12:56] Tankmaster Finesmith: probably, seewo
[12:56] Lucia Nightfire: I forgot I was able to do that too
[12:56] Seewo (siwo): I missed the first half :c
[12:57] Mona Eberhardt: If you guys want, I'll copy/paste what was said on to a notecard and I'll give it (after cleaning it up to remove extraneous notifications) to anyone interested.
[12:57] Kennylex Luckless: take care and have fun.
[12:57] Whirly Fizzle: Th log should go up on https://wiki.secondlife.com/wiki/Server/Sim/Scripting_User_Group soonish anyway
[12:57] Mona Eberhardt nods
[12:58] Yuzuru Jewell: Thank you, Whirly and Mona. I will get it because I was late, too.
[12:58] Jenna Felton: i have to go, too.
[12:59] Lucia Nightfire: Rex is gonna hate me now, lol
[12:59] Seewo (siwo): :D
[12:59] Jenna Felton: thank you Lindens for the meeting and everyone for coming, and have a nice week
[12:59] Mona Eberhardt: You too, Jenna.
[12:59] Yuzuru Jewell: Thank you, Oz and Kelly and Simon.
[13:00] Simon Linden: Thansk everyone - sorry to go afk during this but I think things are sorted out
[13:00] Kelly Linden: Cheers.
[13:00] Qie Niangao: Thanks, Lindens... have fun all.
[13:00] Mona Eberhardt: Thanks Lindens.
Simulator_User_Group
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