Wierd bugs in vFG1 - position desync between client-server?

tommalmm

Yesterday I've run vFG1 ~15 times on my healer (still didn't get what I needed, but it's not a "I hate RNG thread"). I had to do reloadui after every few of them because I was starting to get terrible stutter (but that's pretty normal, something I'm used to). Every few of them the last boss would bug for me in some funny ways.

1. I've seen three AOE explosions in a row (like one after another, immediately), people have dodged out of the first one, then came back, then second one killed them (I don't know whether they couldn't see it or were out of stamina to get out quickly, but it seemed like they just totally ignored that), and the third one when I was ressing them (but it didn't damage me in any way).

2. This is the most hilarious of them. In one run someone has started the fight before tank did (so we couldn't read the scroll), so I wiped (should've just walked away to reset the fight, but who cares), others followed soon after. I respawned, someone has read the scroll, and that's where all the weirdness started to happen. I would die to the AOE explosion even though I was far away from it (like the other side of the room far). My healing springs didn't seem to reach people, my blockade didn't damage the boss. Rapid regen, bol and heavy resto still worked.

Then I've noticed one thing. Whenever I placed channeled focus, it didn't appear under me, but at some points far away from me, sometimes I couldn't even see it (might've ended up in a wall or something?). So I guessed that's where the server thinks I am. It wasn't probably simply a different point of origin, because when I moved around (without changing camera angle, so only translation involved), each time I casted the rune, it would appear in a different place, but would not keep the same distance and angle from me. The same actually happened with extended ritual.

On the other hand, when I casted healing springs, I've seen the animation exactly where I pointed, but others said I was casting it at a spot far away from them.

It's an easily soloable vet dungeon, so people had no issue completing it despite my inability to help them much, but it gave me a good laugh.

Now, that I think of it, in one run I've seen a very high level (cp800-950) players dying constantly to EVERY SINGLE AOE explosion and doing some really terrible DPS (like only heavy attacks were registered). At that time I thought they were simply trolling, but now I think they might've gotten the same or similar bug I did. So has anyone else experienced this issue?

Unfortunately, I can't give any steps to reproduce it, but if others have seen this bug too, it might be possible to figure something out.

3. This is merely an annoyance, but if someone has a quest in this dungeon, I see the friendly NPC arrow spray cones and endless hail circles as hostile (red/pink, whatever it is set to), even though these do not damage me. It's annoying because I keep avoiding them while there is no need to (can't help that, it's stronger than me ).

I'm on PC/EU if that matters.

Mystrius_Archaion

Welcome to connection lag. It's either your internet or the server connection or any link in between disconnecting and everything playing catch-up in super-speed once the connection reconnects.

Open your options and enable the pin meter in the user interface, near the fps meter. You will notice after these events that it usually turned red and has a high number. It only does that after it reconnects at least once and shows after the fact. It's less real time and more buggy than other games that have had such meters, but it helps explain problems.

tommalmm

Nah. That's not it. Lag means the server might see you where you have been, say, a second or two ago. If you stay in place longer than the lag is, your position matches perfectly. Here we're talking about constant (over ~90 seconds fight duration) desynchronization (?) of client and server position even when staying at one place for extended periods of time. Lag doesn't work that way.

FWIW, I have fps and latency meters always on (if latency gets to some really high values, like 90+, I have to slow my rotation a little bit, as I'm starting to miss a lot of light attack weaves, it helps me adjust a bit instead of headbutting the wall).

Usually my latencies are fine, but lag strikes every now and then, yet I have not seen anything like that in about two years I play the game.

rhapsodious

The multiple AOE explosions is something I've seen and it's really annoying as a melee DPS. It's almost like the boss tries to do the attack, can't "finish" it/can't flag it as complete for some reason (terrain issues?) and just keeps trying until it's satisfied. Kind of like how as a player when you try to put down a DOT like Endless Hail or the destro ult, you click to confirm the target area, and it does the shrinking circle animation but nothing happens.

The second issue definitely sounds like desync. It's not something unique to the dungeon since it happens in other areas (such as the fire mages you have to interrupt in round 8 of VMA...) where the server coordinates and your client coordinates somehow get knocked out of sync. But if it makes you feel any better it's not just you. :P

Mystrius_Archaion

tommalmm wrote: »

Nah. That's not it. Lag means the server might see you where you have been, say, a second or two ago. If you stay in place longer than the lag is, your position matches perfectly. Here we're talking about constant (over ~90 seconds fight duration) desynchronization (?) of client and server position even when staying at one place for extended periods of time. Lag doesn't work that way.

Uhh, yes it does.
The game server is constantly checking position and issuing corrections, but it can't do so when there is a complete disconnect for an extended period. It is also storing up ability activations for your client side to run when it reconnects. If it is long enough and information too far different then the server will often kick you when it reconnects, and only when it reconnects or hits a very much longer time-out.

You know why this game behaves as it does? It does so because the alternative way where both the server and client side must agree on position is worse.

Champions Online, another MMO, had the worst lag ever, and may still have it. As soon as you lag and it rubber-bands you back to a previous position, you better pray it gets perfect connection and fixes itself. If it doesn't then it will rubber-band you back to the previous position then forward once the server receives your forward position data then back again as it re-receives the after rubber-band position update and continues repeating not allowing you move or break out of the endless cycle until it crashes the game. If you login again quick enough, it will still be stuck in the rubber-banding loop and crash your game again. It would move you without any input just based on position updates that weren't error checked.
I quit that game when I had less reliable internet due to that happening nearly every 5 minutes for a while there. I called it the "infinite rubber-banding loop" or "infinite lag" and posted on their forums exactly how it worked and how they could fix it to work as other games due to avoid it.

Yes, this game does lag and desync completely, depending on your connection, where it has to play catch-up. It will not show the disconnect on the ping meter until several seconds after it reconnects. I have learned this from watching my own end of the game do this.
We're just lucky it doesn't stick us in an infinite loop and kick us out of the game every time.

Mystrius_Archaion

rhapsodious wrote: »

The multiple AOE explosions is something I've seen and it's really annoying as a melee DPS. It's almost like the boss tries to do the attack, can't "finish" it/can't flag it as complete for some reason (terrain issues?) and just keeps trying until it's satisfied.

Nope. It's literally all the skill uses being stored up on the server side waiting for your client side to render them. There is a disconnect/lag that causes them to not go through but the server knows this, because of no return confirmation that the information went through, so it keeps sending the same info over and over again and doing the calculations server side against your character health as if you did nothing in response.

The server is master, while the client side is slave, to ensure all players are synchronized. That's why this sort of disconnect and catch-up mechanic happens.
It's as if you just stop responding to the enemy and sit there letting it beat up on you even if you tried to move. The server receives your commands too late and doesn't "change the outcome" to include the supposed time-stamps of your commands. If it did then it would be easy to cheat by causing disconnects and forcing out of spec commands to go to the server.


Edit:
My above example of "infinite lag" on Champions Online is what happens when both the client and server are co-master. They apparently tried to lessen the effect of lag for players by letting the client side update the server position, but they still had the server be the true master and update the client position. So when they both updated to different positions and rechecked the new position against each end's data it got stuck in a recurring loop that guaranteed a crash.
World of Warcraft did it the opposite and much better way. That game allowed the client to be master as far as position and attack data so I, with consistent 1000 ping at the time(bad internet), was able to play as if I didn't have lag at all by timing my skill activations exactly 1 second apart. It was surprisingly playable. Movement was also similar. I once fully disconnected due to lag for over a minute and wandered down an empty cave only to reconnect and find myself trapped by all the enemy spawns I couldn't see or interact with on the way down. I had to fight my way out, but it was definitely cool smooth gameplay.