This project is temporarily discontinued...
Not as gross as it sounds
A mod to improve vanilla performance issues without changing game mechanics.
This mod is intended to improve vanilla server performance by modifying parts of the game logic. However, all modifications are developed in a way that the game logic works exactly the same as vanilla. If you can find any difference between this and vanilla (apart from performance improvements) open an issue and I will fix it.
For easier development the logic is split into multiple modules, each patching a different part of the game. The following list gives an overview about implemented changes.
Whenever an entity travels through a nether portal, minecraft checks all blocks in a big area for nether portal blocks. This takes a lot of time and is therefore cached for a few seconds in vanilla. However, if it's not cached the lookup still causes huge lag spikes.
This module keeps a per chunk list of all portal blocks in that chunk and uses that for the lookup. This way the lookup time is drastically reduced. However, there still will be significant lag spikes due to loading chunks.