Very Many Players

A Fabric mod designed to improve server performance at high playercounts.

VMP is still in early development and things may break. Please report any issues to our issue tracker.

So what is VMP?

Very Many Players, or VMP for short, is a Fabric mod designed to improve general server performance at high playercount without sacrificing vanilla functionality or behavior.
For the best performance it is recommended to use VMP with Lithium.

How VMP achieves its performance improvements?

This list may contain features currently unreleased and only found in development builds

Server-side game logic performance improvements:

Uses area maps to optimize nearby packet sending and player lookups
Uses cache to optimize entity trackers, fluid state lookups and ingredient matching
Optimizes entity iteration for collisions
Optimizes ticket propagator using MCUtil from the Paper project (patch licensed under MIT)
Makes initial chunk loading async on player login

Client-side game logic performance improvements:

Makes time source to use built-in Java time source instead of GLFW via JNI calls

Networking performance & responsiveness improvements:

Uses our own chunk sending mechanism (optionally with packet-level rate-limiting)
Adds packet-level per-player render distance
Makes vanilla tcp connections more responsive using packet priority from raknetify
(works best when the server is connected without reverse proxies such as velocity and ssh port forwarding)

Other improvements:

Uses AsyncAppender to improve logging performance and keep logging IO off main thread

... and more

Support

Our issue tracker: link
Our discord server: link

Building and setting up

JDK 17+ is required to build and use VMP
Run the following commands in the root directory:

./gradlew clean build

License