Direct answer
This is a Leaf optimization for reducing goal-selector processing on inactive entities. It is not the same as disabling all mob AI or changing the server-wide simulation distance.
This is a Leaf-specific configuration option, not a general Paper or Folia setting. Confirm the key is present in the configuration generated by your own build before changing it.
How to check it
- Reproduce a workload with many inactive or distant mobs, then profile goal-selector and entity-tick work.
- Separate AI-heavy villagers or monsters from passive entities and from mobs made active by nearby players.
- Document farms or plugins that intentionally manipulate entity awareness before testing.
What to change
- Check whether this key exists in the generated Leaf global config for your specific build; published references show it under performance.
- Test the current behavior first. If changing it, shut down, save the original configuration and change this one key only.
- Do not assume entities that are inactive or unaware will behave identically when this option is toggled.
- Copy the current configuration and note the previous value before running a controlled test.
Software and version notes
Published configuration path: performance.inactive-goal-selector-throttle.
The setting concerns inactive goal selection, not general entity pathfinding thread count. Folia, Paper and other forks may not expose this key.
The archived Leaf global YAML documents the 1.21.1 branch; newer official examples differ. Do not copy an older default or missing block into a current server without verifying that release.
Verify the result
Compare profile costs near and away from populated farms; also test mob targeting, breeding, villager work, and scripted AI interactions used by your server.
Keep the A/B test results, server build, config diff and rollback notes together so the result can be reproduced.