Troubleshooting Server Lag Beyond CPU/Memory/Latency

Tags: performance, lag, troubleshooting, hosting

When hardware and ping look fine but players still rubber-band, the bottleneck is usually I/O, world churn, or misbehaving mods. Use the checks below to isolate the culprit.

Quick checks

• Disk I/O: monitor world save intervals; slow SSDs or RAID resyncs stall chunk writes.
• Chunk churn: huge view distances and many traders force constant chunk loading.
• Mods: a single broken prefab or XML typo can stall the main thread.
• Garbage collection: long pauses often show as short freezes during horde nights.

Stabilize the world

• Trim view distance to 8–10 and reduce MaxSpawnedZombies and MaxSpawnedAnimals gradually.
• Verify prefab packs with --validate tools (NitroGen/KingGen) before deploying to live.
• Keep the save folder under control: move old regions out and run a server-side repairchunkdensity after major updates.

Mod hygiene

• Test new mods on a staging server first and add them one at a time.
• Use consistent versions across client and server to avoid endless XML warnings.
• Check logs for repeating stack traces; remove or patch the mod causing them.

Network path

Even with low ping, unstable routes can drop packets. If players share the same ISP and all report spikes, try a different upstream or move the server region closer.

Observe and iterate

Enable verbose logging during a horde night, note the timestamp of each hitch, and match it to saves, chunk loads, or mod messages. Adjust one setting at a time and keep a simple changelog so you know what actually fixed the issue.