Major TPS lag when exploring the overworld

[EntityIridescent]

Massive TPS lag and freezing when opening a new world and exploring with Futurepack version 1.16.5 31.3.7008.

To Reproduce
Steps to reproduce the behavior:

1. Create new world with Futurepack mod installed.
2. Fly around a bit.
3. TPS standstill until Minecraft is force closed. Logs only indicated info spam with FPChunkScanner, and java.lang.NullPointerExceptions when attempting to interact with blocks.

Futurepack is included in a custom modpack, but error is minimized if not disappearing entirely when backporting to version 31.3.7005 (temporary fix).

Minecraft Version:
1.16.5

Forge Version:
1.16.5-36.2.34

Futurepack Version:
1.16.5-31.3.7008

Logs:
(https://gist.github.com/EntityIridescent/f3ff364bc943c908648f115cccacce67)

[mcenderdragon]

is jsut futurepack isntalled or are other mods present as well ?

[EntityIridescent]

There are other mods present, but issues resolve when Futurepack is removed. Issues also resolve when Magnesium/Rubidium and related mods (Mg/Rb extras and dynamic lights) are removed, possibly indicating some incompatibility.

[mcenderdragon]

There are other mods present, but issues resolve when Futurepack is removed. Issues also resolve when Magnesium/Rubidium and related mods (Mg/Rb extras and dynamic lights) are removed, possibly indicating some incompatibility.

well those mods "improve" performance by breakign mods and assumptions that are normally true when they arent installed.

You can try to use VisualVM to find out what id cuasing the lag by using the CPu Sampler and run ti for some time and then send me the results.

[EntityIridescent]

Issue persists when removing Mg/Rb and related. Server seems to have major tick lag whenever a "Buffering: 101" event is logged (see new log). It seems like some kind of memory/CPU leak linked with generating the small tec dungeons. When the Blame mod is installed, it mentions a loot issue with those tec dungeons. Sometimes it manages to load, but sometimes the world stops entirely.

Log:
https://gist.github.com/EntityIridescent/90a64940c2440737174278d6b33df9ea

[mcenderdragon]

the loot table messages is also generated when code checks if the loottable is available (jup there is no way to check if things exist, you need to request the loottable and then check if its empty...)

and reading the log upwards, you have installed tons of other mods that are effecting world gen, so of course whenever a BUffering: 101 is printed there is lag, because well 101 new chunks are currently generating. the whole system is async so it doesnt block the mian thread and as its only saying 101 and not 200, 300 and so on there is also no memory leak.
A "CPU leak" doesnt exist, atleast I have no idea what you mean by that. Did you find aynthign with VisualVM ? Also updating to a never java 8 version will help. you are suing 51, latest was soemthing like 350+ (so lots of bug fixes and improvements)