Factorio Forums

Hello,

Ive got the following problem. I rented a Factorio server (on low.ms, Upgraded today to 1.1.7) and my two mates and I got after about 10h of playtime constant desyncs (in the first 10h we got no problems).
The desyncs aren't connect to a specific action, sometimes I can play over 30min without one sometimes less than 1min, it happens if I build stuff or only standing still without doing or clicking anything. And the desyncs don't happen at the same time for us.

The game runs with a huge load of mods (around 60, biggest is Krastorio 2) and I know that any mod can cause this but if I host a Game (with the same mods, settings etc) direct on my computer we got no problems. And that's what confuses me, if a mod causes desyncs shouldn't the desyncs keep happening?

Is there anything I can do on the server settings to prevent desyncs? I made a file integrity check on steam and reinstalled the server. Latency on the headless server is about 9-11 ticks for everybody (the same if I host a game directly).

If needed I can provide a desync report a save and all mods, but since I have potato internet it would take a while to upload it.

See 53851, you can remove mods until it works. Without the report no one can tell you what the cause is.

The latest Desync Report (done nothing on desync and alone on the server)
https://drive.google.com/file/d/1MPSyRm ... sp=sharing

And the Save
https://drive.google.com/file/d/18DIO2S ... sp=sharing

Server is now 1.1.8 and until now the desyncs only happen on the headless Server (today we got a solid two hours without any problems and then desyncs every few seconds). If I host the game directly on my computer for my two friends it's all fine.
I tried some mods but without success.

The main difference flagged in the heuristics file is tagged <random-generator>. I don't really know how to parse these files (very few people do) but it makes me suspect that one of the mods you are using is using some kind of multiplayer-unsafe method for picking random numbers. There is no information about which mod it is (at least as far as I can see).

Thanks for looking into the Report. At the moment we don't play on my server but one of us host the game direct and that works without any disturbance.

Sunabouzu09 wrote: ↑

Sun Jan 10, 2021 12:42 pm

Thanks for looking into the Report. At the moment we don't play on my server but one of us host the game direct and that works without any disturbance.

Desyncs are more likely to happen if you have a non-hosting player who connects and disconnects and reconnects. They are often caused by some state changing on the host while the other player is "away" and not being transferred back to the player when they rejoin - mods are supposed to make sure that this can't happen but it's not very obvious to new modders that this can be a problem. So if just a couple of people are playing and joining at the same/very similar times and the hosting player shuts the game down to resume later, the desync is much less likely to happen; with a headless remote server, both the players are non-hosting and in theory they could both become desynced with the server, but if you are hosting it yourself and the other player is only connecting to you, then only they can get desynced with your game, and the less time your hosted game runs without them present, the less likely it is some state will change to cause any desync. Plus whatever it is in the mod may be rare/minor in the first place, so you are making it even rarer this way. But if there really is an MP-unsafe issue in one of the mods, it could strike at any time.

Disclaimer: I can't tell if it really is one of the mods that is causing the problem and you're using too many mods for me to volunteer a lot of time to check them all out, someone with more experience in reading desync reports might be more help.