PulseTest

PulseTest is a lightweight Minecraft Paper plugin that lets server operators generate controlled CPU and RAM load to test performance and stability. Run `/stress start CPU <percent>` or `/stress start RAM <percent>` to simulate load and observe TPS, MSPT and memory behavior.

Key Features

- Start CPU stress by percentage (1%–400%) to simulate main-thread load (intensity is percent of a 75ms baseline per tick). - Start RAM stress by percentage of JVM max heap (1%–100%) with retained allocations to pressure the GC. - Simple commands: `/stress start CPU|RAM <percent>`, `/stress stop` (stops all), `/stress status` (shows current status), `/stress reload` (reloads config). - Safety: configurable max OOM events (default `3`) — test auto-stops after repeated OOMs. - Fully server-side, no client mods required. - Lightweight, focused, and configurable via `config.yml`.

Functionality

PulseTest provides two compact stressors:

- RAM — busy-waits on the main thread for a configurable fraction of tick time (uses a 75ms baseline). This lets you simulate varying CPU pressure and observe MSPT/TPS effects. - RAM — allocates and retains memory in small chunks until a target percent of the JVM heap is reached, holding that memory to pressure the garbage collector. The RAM test will auto-stop after repeated OOMs if configured.

Use `/stress status` to see current allocated MB, targets, and OOM counts.

Installation

PulseTest is a server-side plugin. Drop the built JAR into your `plugins` folder and restart or reload your server. Edit `plugins/PulseTest/config.yml` to adjust `memory.maxOOMs` (default `3`) and run `/stress reload` to apply changes at runtime.

Disclaimer

PulseTest intentionally stresses your server — running high CPU percentages (especially >100% or up to 400%) or targeting near-100% heap can cause large MSPT spikes, OOMs, or crashes. Use with caution on production servers and leave headroom when testing.