Simulation Distance Changes on Own

[Chrisspy36]

Modpack

FTB Skies 2

Modpack version

1.8.0

Launcher

CurseForge

Describe the bug

The simulation distance continuously changes, I normally keep it on 16 chunks, it varies from going down to 5 chunks to 8 to 15 at random. I can't seem to pin point if any action causes it.

Steps to reproduce

Play as normal
Randomly check settings to see the change

Log Files

No response

Expected behaviour

The simulation distance stays on the number I set it to.

Has the pack been modified

No

Additional information

No response

[Appulcake]

This is (very likely) because of Servercore included in the pack, which by default dynamically adjusts a couple settings based on your performance. Check config/servercore/config.yml in the instance to change this behaviour. I think every time this change occurs it also gets logged in logs.

By default it dynamically lowers simulation distance to between 2 and 8 based on performance in MSPT (ms per tick), if your ticks start taking longer than 35ms (which would be 28 TPS, so approaching the point where soon you'll dip below 20 TPS and lag), it'll adjust various settings there like chunk tick distance, mobcap percentage, simulation distance, and view distance.

[Chrisspy36]

I have noticed also that in my pink slime farm that it won't let me spawn anymore animals when it's well below the point of them dying to entity cramming or anything of that sort. Is there a way to disable this? Would my world suffer catastrophic issues if I do disable it?

[WyFryMU]

@Chrisspy36 , the whole job of servercore is to keep the server/world running at it's normal speed of 20 ticks per second. By disabling it, you could start lagging if your laptop/pc isnt strong enough or if you poorly make machines/chunks/automations. You can remove the servercore mod from the modpack and see how if you lag or not, but if you begin to lag again, you can re-add the mod. So nothing catastrophic can go wrong besides lag.

[Appulcake]

The mob and breeding caps are also in the same servercore config I mentioned previously. It by default also handles mobcaps, lowers mob cap limits based on dynamic performance (in default setup, it first lowers chunk tick distance from 10 to 2, then mobcap percentage from 100 to 30, then simulation distance from 8 to 2, then view distance from 10 to 6, as long as there's a performance deficit it goes through that in that order of priority).

By default there's also a breeding cap enabled for villagers and animals, which gives them a certain cap (32 by default) within a certain range (64 blocks by default). You can set up all of this in there, but as WyFryMU's reply, servercore doing this means your game is getting close to lagging and if it didn't do this, there's a chance it'd already have started to lag. If you need assistance diagnosing performance issues, we'd gladly help out in the #java-support channel in FTB Discord.

[Chrisspy36]

Okay thank you both, so if when I go to the config that @Appulcake mentioned once I get all the way down to the actual file can I just remove the file intact, save it on my desktop as not to loose it, then if it lags too much to be playable I can just put the file back?

[Appulcake]

If you remove a config like that, it'll just be regenerated on next launch on the mod's default settings. If you wish to change the functionality in the config, you could edit the file, with e.g. Notepad.

The config used in Skies 2 is somewhat changed from the default, with a couple performance improvement features on and also cross-mod compatibility. So ideally yes back up the file before doing anything with it so you can restore it later, otherwise if you delete it or it gets messed up, and it regenerates the config again fresh, it'll be all different settings from what the pack ships it with.

Otherwise here's an included version of the default servercore/config.yml as of Skies 1.8.0 if something happened to it now before backing it up: config.yml