PulseNet

The Heartbeat of High-Performance Networking - Fabric Edition by BorisShoes

PulseNet is a Fabric mod that brings high-performance packet batching to your Minecraft server. By replacing standard per-packet network flushes with intelligent batching, PulseNet reduces system call overhead and CPU usage while maintaining low-latency delivery of critical packets.

Project Overview

PulseNet is a Fabric mod that replaces Minecraft's default per-packet network flushing with a smart batching system. Outgoing packets are grouped and flushed together, drastically reducing kernel syscall overhead and event loop task scheduling while keeping combat, chat, and other latency-sensitive packets instant. Designed to work seamlessly alongside other Fabric mods via Mixin compatibility.

Installation

PulseNet is a server-side Fabric mod. Drop it into your mods/ folder alongside Fabric API.

Requirements:

Fabric Loader 0.18.5+
Fabric API
Minecraft 26.1+
Java 25+
Latest Builds: https://modrinth.com/mod/pulsenet

Features

Feature	Description
Smart Packet Batching	Groups outgoing packets within a tick and flushes them in a single kernel syscall instead of one per packet. Supports three modes: `smart_execution`, `strict_tick`, and `interval`.
Write Queue	Replaces per-packet event loop task submissions with a single batched write task, eliminating lambda allocations and cross-thread scheduling overhead.
Packet Coalescing	Bundles similar low-priority packets (particles, sounds) into `BundlePacket`s, reducing the client's received packet count.
Explosion Optimization	Detects mass block changes from explosions and replaces individual block update packets with a full chunk resend when a configurable threshold is exceeded.
Packet Classification	Automatically classifies packets as Critical, Instant, Chat, Ignored, or Coalesce — ensuring latency-sensitive packets (keepalive, disconnect, combat) always bypass the buffer. Fabric infrastructure packets (`minecraft:register`, `minecraft:unregister`) are handled at the Connection level to prevent mod handshake failures.
Real-Time Metrics	Built-in metrics system tracking logical/physical PPS, bandwidth, CPU usage, memory savings, and write queue efficiency. Viewable via commands or an in-game boss bar.
Mixin Compatibility	Uses a `@WrapOperation` approach that runs after all other mixins (Polymer, server-side translations, etc.), ensuring full compatibility with the Fabric mod ecosystem.
Hot-Reloadable Config	All settings are configurable via `pulse.properties` and in-game commands (`/pulse config`, `/pulse reload`) with no restart required.

Commands

Command	Description
`/pulse`	Displays the current PulseNet version.
`/pulse reload`	Reloads the configuration from disk.
`/pulse config`	View and modify all configuration settings in-game.
`/pulse netstats [network\\|cpu\\|ram\\|all]`	Displays real-time network, CPU, and memory statistics.
`/pulse netstats bar`	Toggles the metrics boss bar overlay.
`/pulse netstats reset`	Resets all metrics counters to zero.
`/pulse packetNames`	Lists all observed packet class names and channel IDs.
`/pulse packetNames classes`	Lists only observed packet class names.
`/pulse packetNames channels`	Lists only observed custom payload channel IDs.
`/pulse packetNames reset`	Clears the observed packet name lists.

Config Commands

The following commands can be used to adjust configurable settings in the pulse.properties file without a server reboot (Use /pulse reload after running these commands to hotswap changes). These commands can be suffixed with a value to set the setting, or used without a value to view the current setting.

/pulse config batchingEnabled Master toggle for the smart packet batching system. When true, outgoing packets are buffered and flushed in batches instead of individually. (default: true)
/pulse config batchingMode Batching mode: smart_execution (flush on tick + limits), strict_tick (flush only on tick end), interval (flush on a timer). (default: smart_execution)
/pulse config batchingMaxBatchSize Maximum number of packets to buffer before forcing a flush. (default: 1024)
/pulse config batchingMaxBatchBytes Maximum bytes to buffer before forcing a flush. (default: 32000)
/pulse config batchingFlushInterval Interval in milliseconds for the INTERVAL batching mode. (default: 25)
/pulse config batchingSafetyMarginBytes Safety margin in bytes subtracted from the max batch bytes limit to prevent overflow. (default: 64)
/pulse config batchingInstantPackets List of packet class names that should flush the buffer immediately when sent. (default: ClientboundHurtAnimationPacket, ClientboundDamageEventPacket, ClientboundBlockEntityDataPacket)
/pulse config batchingIgnoredPackets List of packet class names that should always bypass the buffer entirely. (default: [])
/pulse config batchingInstantChannels List of plugin channel IDs (e.g. axiom:hello) whose custom payload packets should flush the buffer immediately when sent. Use /pulse packetNames channels to discover channel IDs. (default: [])
/pulse config batchingIgnoredChannels List of plugin channel IDs whose custom payload packets should always bypass the buffer entirely. Use /pulse packetNames channels to discover channel IDs. Note: minecraft:register and minecraft:unregister are handled at the Connection level and always bypass the buffer regardless of this list. (default: [])
/pulse config batchingChatPacketsBypass When true, chat-related packets bypass the buffer for instant delivery. (default: true)
/pulse config batchingOffThreadBypass When true, packets sent from off the server thread bypass the buffer. (default: true)
/pulse config batchingWriteQueue When true, buffered packets are queued and written in a single event loop task instead of calling Connection.send() per packet, eliminating per-packet lambda allocations and cross-thread task scheduling. (default: true)
/pulse config batchingPacketCoalescing When true, packets in the coalesce list are bundled together into BundlePackets on flush, reducing the client's received packet count. (default: true)
/pulse config batchingCoalescePackets List of packet class names to coalesce into BundlePackets (e.g. particles, sounds). Supports inner classes with dot syntax (Foo.Bar). (default: ClientboundLevelParticlesPacket, ClientboundSoundPacket, ClientboundSoundEntityPacket)
/pulse config batchingCoalesceBundleLimit Maximum number of sub-packets per BundlePacket. Vanilla client enforces a hard limit of 4096. (default: 4000)
/pulse config optExplosionsEnabled When true, block updates from explosions are grouped by chunk and replaced with full chunk resends if they exceed the threshold. (default: true)
/pulse config optExplosionsBlockChangeThreshold Number of block changes in a single chunk required to trigger a full chunk resend instead of individual updates. (default: 512)
/pulse config optExplosionsLogOptimizations When true, logs a message each time the explosion optimization replaces block updates with a chunk resend. (default: false)
/pulse config metricsEnabled When true, the metrics collection system is active and computes network statistics. (default: true)
/pulse config metricsUpdateInterval How often (in seconds) the metrics system recomputes derived statistics. (default: 1)
/pulse config metricsModuleNetwork Enables the network metrics module (PPS, bandwidth). (default: true)
/pulse config metricsModuleCpu Enables the CPU metrics module (process CPU usage estimation). (default: true)
/pulse config metricsModuleMemory Enables the memory metrics module (saved allocation estimation). (default: true)
/pulse config metricsModuleWriteQueue Enables the write queue metrics module (event loop task savings tracking). (default: true)

Permission Nodes

PulseNet uses the Fabric Permissions API for command permissions. Each node has a fallback vanilla permission level for servers without a permissions mod.

General

Node	Default	Description
`pulsenet.pulse`	`ALL`	Access the `/pulse` base command (shows version)
`pulsenet.reload`	`GAMEMASTERS`	Reload the PulseNet config file
`pulsenet.netstats`	`GAMEMASTERS`	View network, CPU, and memory statistics
`pulsenet.netstats.bar`	`GAMEMASTERS`	Toggle the metrics boss bar overlay
`pulsenet.netstats.reset`	`GAMEMASTERS`	Reset all metrics counters to zero
`pulsenet.packetnames`	`GAMEMASTERS`	List observed packet class names and channel IDs

Config

Config commands are generated dynamically per config value. The <name> below corresponds to the camelCase config key (e.g. batchingEnabled, metricsUpdateInterval).

Node	Default	Description
`pulsenet.config`	`GAMEMASTERS`	List all config values
`pulsenet.config.<name>.get`	`GAMEMASTERS`	Read a specific config value
`pulsenet.config.<name>.set`	`GAMEMASTERS`	Change a specific config value

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	Limited AFK	AFK detection and management with configurable kick thresholds for servers.
	Links in Chat	Makes URLs posted in chat clickable.

Support and Contributions

PulseNet is an open-source project by PulseMC. We welcome contributions regarding Netty, Mixin, and protocol-level optimizations.

Pulse Discord: Join our community
Boris's Discord: Boris's Modding Discord
Issues: Report bugs on GitHub

PulseNet: The Heartbeat of High-Performance Networking.