KAllFix

KAllFix

Optimization and multithreading written by n1luik

by
8.0K Downloads
forgelibraryoptimizationutility
Rent Server with this Mod

About this Mod

Overview

  • This project is used to fix and optimize issues caused by other mods, and it works on servers.
  • The project contains two main parts: k_all_fix and k_multi_threading, with features mainly controlled by JVM parameters.
  • No regular config file is provided; configuration is mainly done through startup parameters.
  • Client-side usage is supported from 1.0.4.0 onward (requires JVM parameter -DKMT_Client=true).
  • Under a multi-mod and single-threaded baseline environment, cause no issues is not guaranteed, but you could create an ISSUE on Github and the author will fix it quickly.
  • With some mod combinations, clients may still need to install this mod even if it has no visible effect.

Features and Use Cases

Optimizations

Fixes

Multithreading

Introduction

  • Multithreading supports includes block ticks, block entity ticks, entities, dimensions, player packet receiving (manual toggle, client-only), and player login (manual toggle), and also fixes some problematic single-threaded mods by applying multithreading.
  • Multithreading is enabled by default on the server side.
  • In multithreaded scenarios, thread-pool interception or limit-exceeded errors may appear, but they usually do not crash the server.
  • It is recommended to manually set -DKMT-threadMax=[CPU thread count]; otherwise world generation may be frozen. If freezes still occurs after setting it, increase the value higher.
  • Before 1.0.4.0, clients cannot use multithreading; from 1.0.4.0 onward, clients can enable it via -DKMT_Client=true.
  • After 1.0.3.3, ParaServerChunkProvider, TaskRun, and some chunk generation code depend more heavily on C2 compilation (the JVM will enter C2 automatically after running for a while).
  • In Windows Server 2022 Datacenter 21H2 20348.3091 (author's environment), rare thread scheduling anomalies may occur and causes abnormally high CPU usage; the solution is to restart the server.

Related JVM Parameters

  • -DKMT-threadMax=[number]
    • Sets thread-pool thread count.
  • -DKMT-callMax=[number]
    • Sets the default maximum number of threads that multithreaded tasks may use.
  • -DKMT-ThreadpoolKeepAliveTime=[milliseconds]
    • Sets how long idle threads are kept before recycling.
  • -DKMT_D=[any characters]
    • Disables multithreading.
  • -DKMT-OpenVanillaServerChunkCache=true
    • Forces the vanilla ServerChunkCache fix path (added in 1.0.5.3).

JVM Parameter Overview (all retained)

Basic and General

  • -DKAllFix_D=[any characters]
    • Disables KAllFix.
  • -DKMT_Client=true
    • Enables multithreading-related features on the client side (1.0.4.0+).
  • -DKAF-DisablePetrolpark=false

Connection and Timeout

  • -DKAF-ClientboundKeepAlivePacket_Max=[milliseconds]
    • Changes the timing requirement for ClientboundKeepAlivePacket (default 15 seconds; vanilla must be <30 seconds or the player is kicked for timeout).
  • -DKAF-ServerTimeout=[seconds]
    • Sets server connection timeout.
    • May be ineffective in some cases (both parameters are needed because Forge's forge.readTimeout only covers server packet-read timeout, not client/server network threads with players).
  • -Dforge.readTimeout=[seconds]
    • Forge packet-read timeout parameter (used together with the previous parameter).

Mixin / NBT / Auto Command

  • -DKAF-RemoveMixin:[class name]
    • Disables a specified mixin (k_multi_threading mixins can also be disabled).
  • -DKAF-NbtIoMixin_NotGZip=true
    • Adds try-catch to NBT IO for non-gzip scenarios (unsafe; requires commons-compress in the environment).
  • -DKMT-ChunkGeneratorMode2Start=[true,false]
    • Automatically runs: /SetterWorldConfig world setM2 %%KMT-ChunkGeneratorMode2Start%%.

Breeding Control

  • -DKAF-ChunkBreedingControlSize=[number]
    • Disables breeding when chunk entity count exceeds the given value; disabled if the parameter is missing / not a numeric array / empty.
  • -DKAF-ChunkBreedingControlSizeEnable=[true,false]
    • Internal cache switch for detection results; manual setting may be overridden by the program.

Optional Features

  • -DKMT-SafeUnloadChunk=true
    • Enables chunk unload in chunk-generation threads (recommended only for <1.0.4.2 when related freezes occur).
  • -DIndependencePlayer=true
    • Enables asynchronous player handling (likely provides little to no optimization).
  • -DFixBiolithBugMode2=true
    • Attempts to fix most Biolith compatibility issues (may introduce major bugs).
  • -DKAF-gtceu.MedicalConditionTrackerMixin=true
    • Disables radiation in GTM.
  • -DKAF-RemoveClientboundKeepAlivePacket=true
    • Disables vanilla ClientboundKeepAlivePacket (ping can no longer be calculated).
  • -DKAF-RemoveFlyingTest=true
    • Removes flight checks.
  • -DKAF-moonrise_fast_palette=true
    • Disable the fast_palette feature from Moonrise.
  • -DKAF-FixTFMGDestroy=true
    • Fixes compatibility between Destroy and Create (Creative Pump cannot properly connect to Create's pipes).
  • -DKAF-Fix_fabric-object-builder-api.jar=true
    • Fixes compatibility between Sinytra Connector's fabric-object-builder-api and forge-47.3.27.
  • -DKAF-FixAllPacket=true
  • -DKAF-ChunkAwareBlockCollisionSweeperFast=true
    • Use approximation algorithm to replace ChunkAwareBlockCollisionSweeper of Lithium

Login Multithreading

  • -DKMT-LoginMultiThreading=true
    • Enables multithreaded login.
  • -DKMT-LoginMultiThreading.ConnectionLock=true
    • Waits for async execution completion at tick end (disabling may improve performance somewhat, but lowers login stability and may crash).
  • -DKMT-LoginMultiThreading.TaskSizeMax=[number]
    • Limits the number of concurrent login tasks (default 8).
  • Login multithreading may cause the server to receive ServerboundMovePlayerPacket early, leading to one error log.

Packet Optimization

  • -DKAF-packetOptimize=true
    • Optimizes some vanilla packets (must be enabled on both client and server).
  • -DKAF-packetOptimize.AttributesReOutputTime=[milliseconds]
    • Sets forced resend interval for attribute-related data (default 2 minutes).
  • -DKAF-packetOptimize.CompatibilityMode.ClientboundBlockEntityDataPacket=true
    • Uses more conservative compression for ClientboundBlockEntityDataPacket (impacts performance).
  • -DKAF-packetOptimize.CompatibilityMode.ClientboundSectionBlocksUpdatePacket=true
    • Uses more conservative compression for ClientboundSectionBlocksUpdatePacket.

Others

  • -DKAF-UnsafeCinderscapesFix1=true
    • Adjusts limits for the high-overhead enableAshFall function in Cinderscapes.
  • -DKAF-fix.asynchronous.ClientboundCustomQueryPacket=true
    • Makes handshake asynchronous, reducing the chance of being unable to join when too many mods are installed.
  • -DKAF-FixConfigAuto=true
    • Automatically changes some config options for compatibility.

Installation and Runtime Notes

  • From 1.0.3.18, it can run directly (installation feature is still kept).
  • Before 1.0.3.18, run the mod's installer first, or use:
    • java -jar k_multi_threading-xxx.jar -i [empty or install directory]
  • Installation only generates k_multi_threading-base.jar and k_multi_threading-asm.jar.
  • Some features may download dependencies (Zstd-jni 1.5.7-2); if download fails, place them manually in game_directory/lib.

Compatibility Notes

  • Using -DKAF-FixConfigAuto=true can automatically disable:
    • logOffthreadEntityAdd in Cupboard.
    • world.tick_scheduler and entity_by_type in Canary / Lithium (you must manually add mixin.world.tick_scheduler=false in config/canary.properties or config/lithium.properties; otherwise these mod will override the multithread fix for ClassInstanceMultiMap).
  • Cases where -DKAF-FixConfigAuto=true should not be used:
    • Possible conflict with mixin.perf.cache_upgraded_structures in ModernFix (disable via mixin.perf.cache_upgraded_structures=false in config/modernfix-mixins.properties).
    • With login multithreading enabled, ParCool (listed as Parkour on page) may require one death after player joining before working normally.
    • Ars Creo may rarely log Modifier is already applied on this attribute!, but will not crash.
    • NuclearCraft: Neoteric fission reactors may rarely calculate cooling incorrectly after server restart.

Commands

  • /debug_GetterClassFile [class name]

    • Exports final runtime class data to the game directory, with filename format timestamp_save.class.
  • /SetterWorldConfig [world, ClearErrorSize, RemoveRemoveErrorSize]

    • Settings from this command are not persistent.
    • ClearErrorSize: clears the recorded count of “errors that caused server crash risk”.
    • RemoveRemoveErrorSize: stops recording crash-risk counts and keeps intercepting.
    • Under world [dimension registry id], available options:
      • setM2 [true,false]: switches to another dimension implementation mode; higher priority than setMultiThreading, but may freeze the game.
      • setMultiThreading [number] (default 0): sets multithread parallel task count for this dimension; independent mode from setM2, and may also freeze the game.

Others

  • Because Minecraft and many mods are fundamentally designed around single-threaded behavior, complete fixes for all issues cannot be guaranteed.

Source Code Usage

Available Versions

KAllFix 1.0.3.14release
MC 1.20.1forge
June 2, 2025
KAllFix 1.0.3.10release
MC 1.20.1forge
May 8, 2025

How to Install KAllFix on Your Server

1

Order Server

Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).

2

Set forge Loader

In the panel under "Egg", select the forge loader and matching Minecraft version (1.20.1).

3

Install Mod

Open the mod browser in the dashboard and search for "KAllFix". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.

Compatibility

Mod Loaders

forge

Minecraft Versions

1.20.1, 1.19.2

Server-side

~ Optional

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

KAllFix server crashes on startup – what to do?

Most common cause: wrong forge version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.20.1). You can switch loaders with one click in the panel.

Is KAllFix compatible with forge?

KAllFix officially supports forge for Minecraft 1.20.1, 1.19.2. The Mado dashboard automatically detects incompatible loader combinations.

Server lagging with KAllFix – how to optimize performance?

Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if KAllFix consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.

Rent Modded Server

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Details

License
GNU General Public License v2.0 only
Server-side
Optional

Supported Versions

1.20.11.19.2