Desyncs from item manipulation between chests, vehicles, etc

[Adamo]

We have encountered desyncs when transferring items, especially from chests indirectly, such as ctrl-clicking the chest to transfer all items, or even ctrl-clicking an item type to transfer. Perhaps it is just the volume of items being transferred with this type of usage? Often the only solution to our desyncs is for the player to reconnect under a new name, however, that doesn't seem to be working anymore. I should mention this is with (usually no more than) 2 players over open internet. Please let us know what information can be helpful.

[Ethrel]

We've had this happen a couple times. I'm assuming it has something to do with the quantity, as you say.

When you are starting up the host, there's an option to set the latency. Try increasing that (higher value). That *may* help. Give both ends longer to deal with the stuff.

[Adamo]

Thank you, yes. I should have mentioned we've been operating at >150ms latency. We are attempting the game at 265ms, which is slightly greater than our maximum observed ping latency. I should have some results this evening.

[Ethrel]

Well, let us know the results!

Side note: Adamo, as in Steve from T&S? Or is that just coincidence?

[Adamo]

Still ran into some desyncs. One desync I was able to reproduce was when I replaced a damaged belt. Repairing the belt first fixed the error, and we were able to continue playing. I think I remember seeing another post about damaged items causing desyncs. Hard to track and reproduce errors for the most part, though, so not really sure how to productively proceed with debugging.

[kovarex]

All the damage related stuff might be (and probably is) caused by the determinism error in biter path finding logic.

Once the biters search (slightly) different path for two different players, they arrive at different time and damage someone at different time or damage building at different time.

Note, that the desync checks check only player data and some additional things (count of entities, production statistics sum etc.). It would slow down the game if it had to check everything.

This means, that for some time, it seems like everything is ok, but once the biter affects something, that is checked for the desync, the desync appears, but the reason is not giving the damage or destroying the building, but the difference between biter positions and states.

[Adamo]

Hmm, OK, thanks, I believe I understand. In addition to the global desync checks, it sounds like some things are checked for desync with greater resolution in the player's local area. Is that correct? So it seems at least a post-fix for this is to repair all of the affected items, but that during combat, the determinism error can and likely will cause desyncs not within our control. We're attempting some repairs to see if this helps stability. Thanks again.

[kovarex]

Well, there are many possible desync causes, so the best is to wait for 0.11.4