Comp stomp games de-synching on v4.8.6.0

[HOkay]

As per the title, myself and a few friends updated to the new v4.8.6.0 patch and we've played a few games against AI now and found that the games drift apart so we end up playing different games.

We're about to try a re-install but we're fairly sure it's only a problem with the latest patch. There's another topic titled "Lag in multiplayer" which I think is trying to describe the same problem.

Can anyone else confirm they are seeing the same behaviour?

[Krieger Blitzer]

That's true... I can confirm this but for sure not only through Comp Stomp games! This sometimes happen even during pvp games btw, as that the game becomes 'desynced' for some unknown reasons when each player suddenly gets into a different scenario or more likely a game on his own world although that all can still chat to each other inside the same running match However that I strongly believe it's nothing about specifically this patch or generally considering only the Bk mod.. simply because I have received some similar reports describing the same issue from several Vanilla CoH players.
So I assume it's probably the old CoH1 wrecked servers!! Not more.

[HOkay]

Hmm, my friends and I have played Blitzkrieg Mod a LOT of times, pretty much since release and in all those games we've never noticed this problem yet it's come up in the last 3 games in a row since we installed the v4.8.6.0 patch.

I'm not saying it wasn't possible before but this patch seems to have aggravated it a lot! Has anyone else noticed this in the past or since the patch?

[Wolf]

Its old issue with any version since the base version of the game got update, there is not a reason why current patch would elevate these problems.

[stadtbub]

Same Problems... 8 Player Maps are not possible to play.....desync after 5 - 10 Minutes....and then everybody play his own game

You wrote its a "old" issue....so is any solution available ? For me is the game with more then 3 Players not playable.....we cant finish any of the 8 Player Maps (Vanilla or BK).....one of us had always this sync Problem.....

[HOkay]

Thanks for the response Wolf, though it doesn't really help unfortunately. All I can comment on is my experience with a LOT of games with my friends and we never ever had the desync problem before the new patch. On v4.8.6.0 we desynched on every. single. game. We have now reverted back to v4.8.2.0 and have only played two games so far, but they were both fine.

It might be an issue with the underlying game but it was definitely brought to light by the latest patch. If it's just us then it's tough luck for us, I just wondered if it was affecting others too.

I'll report back if we get a chance to re-test v4.8.6.0! Happy Blitzing all this is still probably the best strategy game out (I just hope the guys can rescue CoH2 with a Blitz 2 mod someday...).

[Ghost]

My friends and I experience the same issue, wondering if theres a fix for this, or if its just Steam CoH servers being wonky. Very excited about the Blitz going to CoH2 as it is very much needed.

[snakerensky]

This has been an ongoing problem for myself and a couple of friends in compstomps (can't comment on PvP) for the past two or three patches inclusing 4.8.8.0 as we found out last night. It tends to begin with one player in particular who almost always seems to get 4-5 minute lag between him giving his units orders and them actually carrying them out before he gives up and logs out. I then notice my units 'doing their own thing' instead of following my orders which seems to be the sure indicator that the game between the other remaining player and myself have de-synched.

[Wolf]

Can you try playing without that one friend who gets the 4-5 minutes lag?

[snakerensky]

Can you try playing without that one friend who gets the 4-5 minutes lag?

Sure, i'll see if I can get the other one online on the weekend. The game doesn't always de-sync even with the laggy player and his lag seems random too, sometimes none, sometimes within 10 minutes and other times it might take an hour to appear and occasionally even disappears after a while. We always play the three player maps and have only played the German side in recent times, those are the only constants I can think of.

[drivebyhobo]

I upgraded from 4.8.6.3 to 4.8.6.8 yesterday and the one 2vAI comp stomp I played had this diverging games problem.

In my game my teammates units did not move and the newly produced units of my teammate after the desync did not show up. None of my actions appeared in my teammate's game. All of this was also true in my teammate's game.

Other relevant info
We had no issues with unit orders taking an unusual amount of time to process.
There's no lag issue as my teammate is only 10 miles away.
In-game chat messages sent and received normally with no lag.
Both BK installations were new.

[HOkay]

Hey all, me and 2 friends just installed the latest v4.8.8.0 patch and gave that a go, no desync issue at all! This is only one game test but that's already 100% better than the v4.8.6.0 whatever the devs did, kudos!

[Wolf]

Iam afraid we didn't do anything, in a good or bad way, its more Relic network code + steam servers doing these problems. It started right when they removed Sync error message with vCoH patch, which means it does also in vCoH sometimes and we can't or really don't know what should we do to help reduce it.

[snakerensky]

We tried a two player game in version 4.8.8.0 today without our laggy friend which lasted three hours or so and had no desync issues, this of course is only one game but there was no sign of any problem. We will no doubt be trying again on Tuesday evening with our laggy buddy so will see again if we have issues.

[stadtbub]

And again

3 Player (Axis) vs 3 Computer (Allies) - after a while i get the desync.....My teammates see my airstrike...but the Tanks and Soldiers do in my game not the same as in the game from my buddies ....thats interessting....Air Recon is on our Multiplayergames no problem, when any body has desync and call the Airplane so everyone will see the plane and recon area....but the troops do not the same

[MeatshieldNZ]

Its a common problem that showed up after the last VCOH patch, Wolf bought it to Relics attention in the official forums but they never replied:

http://community.companyofheroes.com/fo ... vcoh-patch

You could try PM'ing one of their Community Managers (Noun has since left btw) but I honestly don't think they will do anything if it is only affecting Mods..

One guy I played with had the same issue until he upgraded his PC, still happens but not as bad.

[stadtbub]

And the problem is till alive -.-

Game ist not playable for me and my friends (4 High End PC and High Speed Internet) ..... After 15 Min every Player play his "own" game ....
Any Port Solution ? ...... With this issues the mod isnt playable for us

The Problem is on every map... with 4 pl vs 4 pc or with 2 vs 2 player .....same 15 - 25 Min and then.... Boom...every Player has his "own" game....

German :

Hat jemand das gleiche Problem und evtl schon eine Lösung ??

[JimQwilleran]

Yea, I know it sucks, but everyone here has that problem. Sometimes it happens often and then it's gone for a few weeks. There is no solution to this problem I am afraid. This is probably server's fault .

[Jalis]

it s not server fault. it occurs also in lan games. Form what I experienced It s even not completly related to a communication problem.

[Kasbah]

I play this mod since 2010 and the desync, as well as lag, only started happening with the new version with Sega. Before, with Relic, it was perfect

[Jalis]

Perhaps you changed you game style with steam version ?

I played about all my mp game on DVD version TOV or anthology and LAN, and have desynchro. depending game config, maps and mod, desync risk is more or less predictable.

[Akrean]

LAG:
me and some friends of mine, we have proven that the lag we are experiencing is caused by the pathfinding. Examining the stack-traces of the game while lagging showed, that most of the time is spend during pathing-related functions. Often the cause for such excessive pathfindings are bridges or other bottlenecks where the ai units get jammed. As the units do not move, the ai issues the same move orders over and over again, causing massive recomputations of pathes to occur. As the game is mostly singlethreaded (using only one cpu core) this causes the update-rate of the game going down. As the commands send over network have a timestamp that tells the game about the update cycle in which this command was issued and the different update-rates of the players, one player can start to lag behind (record almost 90min on hochwald gap 2 vs 4 experts), once his update-rate goes below the minimal update rate the game can handle flawlessly. once you (or your mate) unclog the bottleneck sucessfully (causing the ai to stop issuing massive amounts of move orders every cycle) and the lagging player reaches this time point on his machine, the game starts to catch up (units start to race across the battlefield), as the cpu has now the capacity to process more update cycles in the same time-span, thus allowing the lagging player to catch up with his mate (until the ai clogs again)


in order to verify this theory common knowledge about the inner workings of multiplayer rts games, the process explorer from sysinternals (to view the stack traces of the game's threads on the lagging player's computer) and experiments (on hochwald gap, as on this map the expert ai is most likely to clog - especially in fun-mode) where used

DESYNC:
here, we have observed, that the desync usually starts with one unit dying in a player's game-state, but beeing alive in the other players' states. If this unit affects the game state in any way, e.g. by killing another unit the game states now differ. This difference is now propagated, thus leading to multiple completely unrelated games.
Maybe it is possible to cushion the probability for a desync from within the mod. I'd suggest to pause an unit (== making it impossible for this unit to affect the game state in any way) everytime it dies in one player's state. Then all players vote for/the host decides this poor unit's fate. If death is chosen, the unit is killed in all game states, otherwise the unit is set on the common/host's state (all actions leading to this state are executed) and unpaused again. Thus it should be ensured, that whenever a unit dies it is dead in all game states. Potential delay caused by the pausing and voting could be concealed as death-struggle. A problem however would be the lags between the players. To fix this either the most advanced (temporal speaking) player has to dictate the state (suboptimal, as this player could change frequently) or when voting states, players that are too far behind are not allowed to vote.
As I am not sure on how much influence you can have on the game through coding, I am not sure if the proposed solution is implementable or feasible.