Hibernate Fabric

Lets your Minecraft Fabric server snooze when idle, slashing CPU usage without missing a block!

About The Project

Hibernate Fabric is a lightweight tool that automatically puts your Minecraft Fabric server to sleep when no players are online. By reducing CPU usage during idle times, it helps save server resources, lowers your electricity bill, and makes your server more eco-friendly. It's a simple way to keep your Minecraft world running smoothly without wasting power when it's not needed.

Built With

This project is built with the following technologies:

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Run

You will need a Minecraft Fabric server.

1. Download hibernate-fabric-x.x.x+mc2x.x.jar from one of the places at the top of this README.
2. Copy the downloaded jar file to the mods folder of your Minecraft Fabric server.

NeoForge Support Via Compatibility Layer

[!WARNING]
NeoForge is currently supported only through Sinytra Connector which is a compatiblilty layer to allow Fabric mods to load in NeoForge.

Hibernate Fabric can currently be used on NeoForge through Sinytra Connector, but this configuration is not officially supported.
While it works, compatibility depends on both Hibernate Fabric and Sinytra Connector, and future updates to either project may cause it to stop working.

Issues that occur only when using NeoForge/Sinytra Connector are generally not supported and may be closed without investigation.
If you encounter an issue, please first reproduce it on Fabric before reporting it.

In addition to the instructions above:

1. Download and install Sinytra Connector and LaunchPad to the mods folder of your Minecraft NeoForge server.
2. Download and install Forgified Fabric API to the mods folder of your Minecraft NeoForge server.

Getting Started With Development

To get a local copy up and running, follow these simple steps.

Prerequisites

Ensure you have the following installed on your machine:

• Java Development Kit (JDK): Version 25 or higher.
  • Download JDK
• Gradle: Version 9.2 or higher.
  • Install Gradle
• Minecraft: Version 26.2

Build

1. Clone the repository

git clone https://github.com/VoxelBill/hibernate-fabric.git

2. Navigate to the project directory

cd hibernate-fabric

3. Build the project with Gradle

./gradlew clean build

You can find the built mod at hibernate-fabric/build/libs/hibernate-fabric-x.x.x+mc2x.x.jar.

Configuration

The mod automatically creates a configuration file at config/hibernate-fabric.json on first run. Here are the available settings:

Basic Settings

{
  "startEnabled": true,
  "ticksToSkip": 400,
  "permissionLevel": 2,
  "sleepTimeMs": 75,
  ...

Setting	Default	Description
startEnabled	true	Whether hibernation activates automatically when server starts with no players
ticksToSkip	400	Number of ticks to process before applying sleep during hibernation
permissionLevel	2	Required permission level to use hibernation commands (0=all, 4=owner)
sleepTimeMs	75	Milliseconds to sleep between tick processing cycles

Memory Optimization

  ...
  "enableMemoryOptimization": true,
  "memoryCleanupIntervalSeconds": 30,
  "memoryThresholdPercent": 80.0,
  "forceGarbageCollection": true,
  "gcIntervalSeconds": 30,
  "saveBeforeHibernation": true,
  "removeEntities": [
    "minecraft:item",
    "minecraft:firework_rocket",
    "minecraft:arrow",
    "minecraft:experience_orb"
  ],
  "droppedItemMaxAgeSeconds": 300,
  "logMemoryInfo": false,
  ...

Setting	Default	Description
enableMemoryOptimization	true	Enable memory cleanup during hibernation
memoryCleanupIntervalSeconds	30	How often to run memory cleanup routines
memoryThresholdPercent	80.0	Memory usage percentage that triggers cleanup
forceGarbageCollection	true	Force Java garbage collection during hibernation
gcIntervalSeconds	30	Minimum time between garbage collection runs
saveBeforeHibernation	true	Save world data before entering hibernation
removeEntities	item, firework_rocket, arrow, experience_orb	List of entities to remove during hibernation (ignores entities with custom names)
droppedItemMaxAgeSeconds	300	Age in seconds after which items are removed (5 minutes)
logMemoryInfo	false	Log memory usage and garbage collector information to console

CPU Optimization

  ...
  "aggressiveCpuSaving": true,
  "minSleepInterval": 1500,
  "highLoadSleepMultiplier": 1.5,
  "yieldInterval": 8,
  ...

Setting	Default	Description
aggressiveCpuSaving	true	Enable more aggressive CPU saving measures
minSleepInterval	1500	Minimum time in milliseconds between sleep cycles
highLoadSleepMultiplier	1.5	Multiplier for sleep time when system load is high
yieldInterval	8	How often to yield CPU to other threads (every N ticks)

Gamerule Values When The Servers Awake

  ...
  "awakeGameRules": {
    "advance_time": true,
    "advance_weather": true,
    "random_tick_speed": 3,
    "spawn_mobs": true,
    "fire_spread_radius_around_player": 128
  },
  ...

Setting	Default	Description
advance_time	true	The value to set the gamerule advance_time to when coming out of hibernation
advance_weather	true	The value to set the gamerule advance_weather to when coming out of hibernation
random_tick_speed	3	The value to set the gamerule random_tick_speed to when coming out of hibernation
spawn_mobs	true	The value to set the gamerule spawn_mobs to when coming out of hibernation
fire_spread_radius_around_player	128	The value to set the gamerule fire_spread_radius_around_player to when coming out of hibernation

Gamerule Values When The Servers Hibernating

  ...
  "hibernatingGameRules": {
    "advance_time": false,
    "advance_weather": false,
    "random_tick_speed": 0,
    "spawn_mobs": false,
    "fire_spread_radius_around_player": 0
  }
}

Setting	Default	Description
advance_time	false	The value to set the gamerule advance_time to when going into hibernation
advance_weather	false	The value to set the gamerule advance_weather to when going into hibernation
random_tick_speed	0	The value to set the gamerule random_tick_speed to when going into hibernation
spawn_mobs	false	The value to set the gamerule spawn_mobs to when going into hibernation
fire_spread_radius_around_player	0	The value to set the gamerule fire_spread_radius_around_player to when going into hibernation

Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.
If you don't have any coding experience, testing other platforms and configurations is also very welcome!

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement".
Don't forget to give the project a star! Thanks again!

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

Distributed under the GNU Lesser General Public License v3.0 or later (LGPL-3.0-or-later).

This project is a fork of Hibernateforge which was distributed under the European Union Public License v1.2 (EUPL-1.2).
Relicensing has been done in accordance with the compatibility clause of the EUPL (Article 5).

See LICENSE for more information.