"Elf Lag"

• Rydian wrote on 2016-01-20 23:19
  There's been a lot of talk about this one way or the other over the years, and a lot of supposed fixes that may or may not have worked over the years as well. Here's what I can say.
  
  

  • It's a client-side bug.
    
  • It appears to be an actual combat logic bug, not just a stuck animation causing a delay or whatever it may have manifested as in the past.

  
  
  Here's two packet logs of elf ranged combat, with most irrelevant packets filtered out. Red are outgoing (things your game tells the server), blue are incoming (things the server tells the game).
  
  [spoiler="Normal"]

  [Image: http://i.imgur.com/essbqiA.png]

  [/spoiler]This is the log of firing an arrow normally. You tell the server you're going to start aiming at the target, then you tell the server you're going to attack. The server responds and the attack fires off (once you have the server response).
  
  [spoiler="Elf Lag"]

  [Image: http://i.imgur.com/97tpQkx.png]

  [/spoiler]This is the log of what I see when I hit the "elf lag" issue. Things look mostly the same, but for some reason when I went to attack my client just started spamming this unknown packet instead. After a bit of that, that's when it made and sent the proper attack packet.
  
  Anybody got any more info on this?
• Baku wrote on 2016-01-21 00:32
  Way back when, I remember fiddling with some dll removing some frames from the elf animation, and that definitely used to fix the issue, as clear as dying constantly to being able to play just fine. While a couple of mods that mentioned to fix the issue didn't work for me, the modifications I performed fixed it without a doubt, unfortunately it has been so long now that I recall close to nothing as to what I modified precisely. It used to piss me off reading people saying it was just a placebo effect, or that there's no such thing as "Elf lag", when the results were clear as day.
  
  There's definitely a client-side bug with elves ranged attack, it may not be noticeable to some with lower pings, but it becomes much more pronounced as your ping increases.
  
  Mabinogi in general seems to have terrible network programming.
• Step29 wrote on 2016-01-23 17:24
  Elves has a special ability that allows you to "move in position while aiming". The packet 791F is suppose to communicate with the server letting you know you're moving while aiming.
  As for the bug. I don't know. When you use CTRL sometimes the client will tell the server that im going to walk to the enemies position. But I don't know if this occurs while moving while aiming
• tachiorz wrote on 2016-02-01 17:12
  Yeah, I noticed that. I worked on ranged in aura (a bit)
  https://mabimods.net/index.php?topic=16756.msg241592#msg241592
  [SPOILER="paste"]
  I think this is still a client bug. For some reason it starts to send elf aim packet like crazy, causing huge network lag and rendering elf not being able to move or cancel skill for WHOLE SECONDS.
  

  [Image: http://mabinogi.pp.ua/g/16e0d0cde2b3e013ab99ac825c5cd668.png]

  
  I haven't seen it on localhost with aura, but it happens on oficial server very often, I guess this bug is latency related (could be a reason koreans not fixing it for years)
  [/SPOILER]
  
  https://github.com/aura-project/aura/blob/master/src/Mabi/Network/Op.cs#L332
  https://github.com/aura-project/aura/blob/master/src/ChannelServer/Network/Handlers/Skills.cs#L607
• X wrote on 2016-02-02 02:32
  The fact that the ops of the elf packet and setAimR are adjacent is way too much of a coincidence, especially when taken with the fact that there seems to be one SetAimR packet for each elf packet.
  
  So elf lag is probably a bug in the client, where it mistakenly spams the packet until it gets a response. As you say, with Aura/KR, this response would come very fast, minimizing the effects of the spam. On NA, though, you'll wind up stuck.
  
  Juding by the timings on the packets, the client gets stuck in a tight loop of sending packets. Something like:
  
  [CODE]while (!responseReceived) {
  sendElfPacket();
  }[/CODE]
  
  If this is all true, it is probably a very easy fix, both for devcat and for anyone who memory edits the client *cough* step *cough*. I'm betting the proper functionality is to only send it once. I seem to recall people fixing it before by just disabling that packet, but I dunno what kind of effects that'd have.
• Madgamer13 wrote on 2016-02-09 21:53
  Greetings!
  
  I am curious to what the server is doing with these weird elf packets. If the server is receiving and processing them, they are likely having an impact on it's cycles, however minor. I would like to ask: Would it be possible to bombard the server with these packets under the right conditions?
• X wrote on 2016-02-09 23:18

  Quote from Madgamer13;1293713:

  Greetings!
  
  I am curious to what the server is doing with these weird elf packets. If the server is receiving and processing them, they are likely having an impact on it's cycles, however minor. I would like to ask: Would it be possible to bombard the server with these packets under the right conditions?

  
  
  
  The client already bombards the server with these packets because devCat.
  
  Anyway, judging by the timestamps of the packets, there's a 300ms delay between when the packet is sent and received. Network transport and other IO operations take the lion's share of that. it takes the server probably less than 10 milliseconds to process the packet. The handler probably involves a few dozen instructions, if that, since it's so simple a packet. Bottom line: you can't DDoS the game with this packet.
• Ghostmonkey wrote on 2016-05-11 05:27

  Quote from Step29;1293127:

  Elves has a special ability that allows you to "move in position while aiming". The packet 791F is suppose to communicate with the server letting you know you're moving while aiming.
  As for the bug. I don't know. When you use CTRL sometimes the client will tell the server that im going to walk to the enemies position. But I don't know if this occurs while moving while aiming

  
  
  now that you mention the skill like that.. "move in position while aiming" would sound a little complex because the server has to see where you are and aim right? no wonder elves have so much lag