Lazy Chunk Load

# Lazy Chunk Load **The vanilla chunk loading system schedules a massive number of chunks around the player all at once, causing instant server CPU overload and TPS collapse.** Lazy Chunk Load improves this process: it controls chunk loading speed like a faucet — automatically turning down when the CPU is busy and opening up when idle — so exploring new terrain no longer stutters. --- ## What This Mod Does ### 🚶 Anti-Lag Exploration With this mod installed, the server **automatically adjusts chunk loading frequency based on current CPU usage**. Full speed when usage is low, automatically slows down when usage spikes — TPS stays rock-solid throughout. - **It doesn't make chunk loading faster** — it makes it smoother. Trade a bit of instant speed for a stutter-free experience. - True prevention, not an after-the-fact fix. ### 🔄 Background Preloading When you're standing still, the mod **automatically uses idle CPU to preload ungenerated chunks around you**. Priority: chunks under your feet first, then in your line of sight, then to the sides and behind. - Enabled by default, works while idling. - Automatically pauses when the CPU is busy — never steals resources. - Status output to log every 5 seconds. ### 🛡️ Additional Protections - **Login Warmup**: No limits for the first 10 seconds after joining a world, ensuring initial terrain loads quickly. - **Save Safety**: Automatically pauses all chunk loading during world saves to prevent save stalling. - **Emergency Bypass**: When the player steps on an unloaded chunk, all limits are bypassed and the chunk loads immediately. - **Hotspot Chunk Tracking**: Frequently-accessed chunks are marked as hotspots; preload extends their retention time. - **Dimension Whitelist/Blacklist**: Restrict preloading scope via `dimension_blacklist` / `dimension_whitelist` to avoid wasting CPU in custom dimensions. --- ## Installation Drop it into your `mods` folder — no configuration needed to work out of the box. Server-side only; clients do not need to install it. Singleplayer works perfectly fine too. | Platform | Supported Versions | |---|---| | Fabric | 1.21.x | | Fabric | 26.1+ | | Forge | 1.20.1 | | NeoForge | 1.21.1 | > 💡 Fully compatible with optimization mods like C2ME, Lithium, and VulkanMod. Does not modify chunk generation algorithms — only adjusts loading rhythm. > 🗺️ Automatically detects Chunky pre-generation tasks and lifts CPU limits during generation for full speed; restores automatically when complete. --- ## Monitoring Every 5 seconds a status line is logged to `logs/latest.log`: ``` [LazyChunkLoad] Tick:1200 CPU:45% Sched:3/t Warmup:N Preload:ON Main:OK ``` | Field | Meaning | |---|---| | `Tick` | Current tick count | | `CPU` | CPU usage percentage | | `Sched` | Chunks loaded last tick | | `Warmup` | Y=Warming up / N=Normal | | `Preload` | ON=Active / OFF=Disabled / PAUSED=CPU too high | | `Main` | OK=Full speed / SLOW=Throttled | --- ## Configuration The config file is located at `config/lazychunkload.json` (auto-generated, takes effect immediately on changes). **If you just want to use the mod normally, you don't need to read any of this — the defaults are already best practice.** 📝 Full Configuration Reference (click to expand) | Option | Default | Description | |---|---|---| | `cpu_threshold` | 0.85 | CPU usage threshold for throttling (0~1, higher = more lenient) | | `warmup_ticks` | 200 | How many ticks after login to skip limits (20 ticks = 1 second) | | `preload_enabled` | true | Enable background preloading | | `preload_radius` | 64 | Preload radius (in chunks) | | `preload_delay_seconds` | 1 | Seconds of standing still before preloading begins | | `distance_weight` | 0.5 | Distance priority weight (closer = more priority) | | `direction_weight` | 0.4 | Direction priority weight (forward-facing = more priority) | | `aging_weight` | 0.1 | Aging priority weight (long-unloaded = more priority) | | `direction_multiplier` | 5.0 | Direction bonus multiplier | | `aging_factor_ms` | 10000 | How many milliseconds count as "aged" | | `log_loading` | false | Log detailed info to console | | `performance_tips` | true | Output debug log when CPU or MSPT exceeds threshold (no longer sent to chat) | There is also a runtime config at `config/lazychunkload-runtime.json`: | Option | Default | Description | |---|---|---| | `limit_enabled` | false | Set to true to completely disable CPU limits (full speed) | | `tips_disabled` | false | Set to true to disable chat performance tips | --- ## How It Works 1. Checks CPU usage once per tick (1-second cache, near-zero overhead). 2. CPU below 85%: chunks load normally, no restrictions. 3. CPU above 85%: chunk loading frequency is automatically reduced — the higher the CPU, the stronger the limit, but **even in the worst case, at least one pass is allowed every 0.2 seconds** — ensuring terrain never gets permanently stuck. 4. When you're standing still: background scanning of ungenerated chunks around you, loaded in prioritized batches. 5. When you're exploring: stepping on an empty chunk triggers an immediate emergency bypass with no limits applied.