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Ember Plugins

Ember Horizon

Trades a little draw distance for the TPS you actually need, and shows you where the tick time went.

1.16.5 – 26.2Java 8+PaperPurpurSpigot

Get Ember HorizonCommands & permissions

Why this does not unload chunks

Plugins in this space usually loop over loaded chunks and call unloadChunk on the ones far from players. That was this plugin's predecessor too, and it is the wrong lever on any modern server.

Paper already unloads chunks nothing wants, through its own ticket system. Asking it to unload a chunk something still holds is ignored; where the call does land, the chunk reloads moments later. You pay for the churn and keep none of the memory. We measured it: 3,600 force-loaded empty chunks moved TPS by almost nothing. Chunks with nothing in them are close to free.

What costs a server is how many chunks are ticked, and what is standing in them. So Ember Horizon adjusts that instead, and tells you where the expensive chunks are.

What it does

Adapts distance to load. Every thirty seconds it compares TPS to two thresholds. Below the lower one it steps distances down; above the upper one it steps them back up. One step per cycle, so nobody gets snapped from 10 to 4 — under real load a player sees the horizon drift in a chunk at a time, if they notice at all.

Drops simulation distance first. Ticking a chunk costs far more than sending one, and players notice the view closing in long before they notice distant mobs pausing. Recovery runs the other way: view distance comes back first. That ordering is most of the quality-of-life difference.

Protects your ranks. A permission can set a floor, so the players paying you are not the first ones squeezed:

emberhorizon.view.10          never below 10 view distance
emberhorizon.simulation.6     never below 6 simulation distance

The highest node a player holds wins, still capped by max in the config.

Finds what is actually heavy. /horizon hotspots ranks loaded chunks by what is standing in them, with block coordinates so you can go and look. Tile entities count double, because a hopper ticks every tick whether or not anyone is nearby.

world  26,-8   (block 416,-128)   entities 61, tiles 0
world  7,-22   (block 112,-352)   entities 0,  tiles 26

Shows what is holding chunks open. /horizon tickets lists every plugin holding chunk tickets, and every force-loaded chunk. Force-loads live in level.dat and survive restarts forever — they are the usual answer to "why is this server eating memory". /horizon sweep clears them, dry-run first.

On older versions

One jar covers 1.16.5 through 26.2, and it tells you what it can and cannot do rather than pretending:

Server What you get
Paper 1.18+ View and simulation distance, per player
Paper 1.16 – 1.17 View distance only — simulation distance did not exist yet
Spigot Distances applied per world; there is no per-player API

/horizon status states which mode it is in. On 1.16 it says simulation: n/a (needs 1.18+) instead of quietly doing nothing.

In pictures

Real output, on a live server.

The heaviest loaded chunks, ranked by what is standing in them, with block coordinates to go and look Clearing the force-loaded chunks that were quietly holding memory, dry run first

Commands and permissions

All of it sits behind emberhorizon.admin (default: op).

Command What it does
/horizon status TPS, current distances, why they last changed, chunk and entity totals
/horizon hotspots [n] The heaviest loaded chunks, with coordinates
/horizon players The distance actually applied to each player right now
/horizon tickets Plugin chunk tickets and force-loaded chunks
/horizon sweep [confirm] Clears force-loaded chunks. Dry run without confirm
/horizon reload Re-reads the config, including the interval

Aliases: /emberhorizon, /eh.

Settling it in

Start with dynamic.enabled: false. You get every diagnostic and no change to what players see. Run /horizon status at your busiest hour: if TPS sits at 20, you do not need the scaling and this stays a diagnostic tool. If it is dipping under 18, turn it on and it will start earning its place.

Network requests

Two, both optional and both off with one line:

  • bStats (metrics: true) — anonymous usage statistics, plugin id 27424.
  • Update check (update-check: true) — one request at startup to see whether a newer version exists. Nothing about your server is sent, and it never downloads or installs anything. It prints a line.

For store posts and reference: