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 BundlePackets, 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

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

Config

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

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