Troubleshooting Server Lag and Performance Issues

Understanding Server Lag

Lag can come from several sources. Understanding which type you are experiencing helps fix it faster.

Types of Lag

• TPS lag (server-side) — The server cannot keep up. TPS (ticks per second) drops below 20. Use /tps to check if your server supports it
• Ping lag (network) — High latency between the player and server. This is usually geographic distance or the player's internet connection
• Client FPS lag — The player's computer cannot render the game smoothly. This is not a server issue

Diagnosing Server Lag

Use Spark to identify what is consuming server resources:

1. Install the Spark profiler plugin (works on Paper, Fabric, and Forge)
2. Run /spark profiler start in the console
3. Let it run for a few minutes during lag
4. Run /spark profiler stop — it will generate a report link
5. The report shows exactly which plugins, mods, or game systems are consuming the most time

Note: Paper previously used Timings (/timings), but this has been deprecated in favor of Spark.

Common Causes and Fixes

• Too many entities — Mobs, item drops, and armor stands in loaded chunks. Use a mob stacking or entity limiter plugin
• Large view/simulation distance — Reduce view-distance and simulation-distance in server.properties. These are the two most impactful settings for TPS
• Chunk loading — Many players spread across different areas forces the server to load more chunks. Chunk loaders make this worse
• Redstone clocks and contraptions — Rapid redstone pulses consume significant server resources
• Poorly coded plugins — The Spark report will identify which plugins are using the most CPU time
• World pregeneration — New chunk generation is expensive. Use a pregeneration plugin (like Chunky) to generate chunks ahead of time

RAM Issues

• RAM at max — Too many chunks loaded, too many mods, or a memory leak from a plugin
• Check your panel for current RAM usage
• Remove mods and plugins you do not need

Network Lag (Ping)

• Ping is determined by physical distance and internet routing — we cannot reduce it from our side
• If a player has poor routing, a VPN with a nearby exit node may help

When to Upgrade

Only upgrade your plan after you have:

• Identified the lag source using Spark
• Optimized your server configuration
• Confirmed the lag is not caused by a specific mod or plugin
• Verified that your resource usage is consistently at the limit under normal load