Ender Dragon unbeatable due to server lag

Are you experiencing problems defeating the Ender Dragon due to server lag? The combination of low TPS (ticks per second), high latency, and the resource-intensive Ender Dragon fight can make the battle impossible or unfair. This article provides concrete solutions for both acute and structural performance problems.

Diagnosis: Server lag or client lag?

Before you start optimizing, first determine where the problem lies:

Server-side lag (this article focuses on this):

TPS (ticks per second) below 20 (check with /tps or /spark tps)
All players experience lag simultaneously
Mobs move jerkily for everyone
Blocks break with delay for all players

Client-side lag:

Low FPS for individual players
Other players experience no problems
Only visual stuttering, no gameplay delay

Immediate temporary solutions

Step 1. Restart the server before the Dragon fight

A fresh server start has no memory leaks or accumulated entities. Access via the game panel at https://game.ping64.net → select your server → click "Restart".

Step 2. Pre-load the End chunks

Teleport to the End and let the chunks load before players arrive:

/execute in minecraft:the_end run tp @s 0 64 0

Walk a circle of approximately 200 blocks around the spawn platform to force chunks.

Step 3. Remove unnecessary entities in the End

/execute in minecraft:the_end run kill @e[type=!player,type=!ender_dragon,type=!end_crystal]

Structural optimizations

1. Lower view distance

Edit the server.properties file via the File Manager in the game panel:

view-distance=6
simulation-distance=4

view-distance: How far players can see chunks (default 10)
simulation-distance: How far mobs/redstone are active (default 10)

For Dragon fight minimum:

view-distance: 6-8
simulation-distance: 4-6

2. Use Paper or Purpur server software

Paper and Purpur are optimized Spigot forks with better performance.

Advantages:

Better entity tracking
Async chunk loading
Configurable mob AI optimizations

3. Optimize End dimension specifically

If you're using Paper or Purpur, edit config/paper-world-defaults.yml:

entities:
  behavior:
    ender-dragons-death-always-places-dragon-egg: true
  spawning:
    all-chunks-are-slime-chunks: false
    alt-item-despawn-rate:
      enabled: true
    per-player-mob-spawns: true
    
chunks:
  auto-save-interval: 300  # Increase for less disk I/O during fight
  delay-chunk-unloads-by: 10s
  
environment:
  treasure-maps:
    enabled: false  # Reduces chunk loading

4. Reduce mob AI complexity

Edit bukkit.yml:

ticks-per:
  monster-spawns: 4  # Increase from 1 to 4
  animal-spawns: 400
  water-spawns: 400
  water-ambient-spawns: 400
  ambient-spawns: 400

Minecraft version specific problems

Versions 1.19 and higher

Versions from 1.19 onwards have significantly higher resource requirements due to:

Chat signing system
Improved entity collision detection
Warden AI (even though it's not in the End)

Recommendation: Consider downgrading to 1.18.2 or upgrading to 1.20.4 or higher (contains optimizations).

Versions 1.20.5 and higher: Dragon fight bug

There is a known bug where the Dragon can get stuck in perching state.

Workaround:

/data merge entity @e[type=ender_dragon,limit=1] {DragonPhase:0}

This resets the Dragon AI to "circling" phase.

Check server resources

RAM usage

The End fight requires at least 2GB free RAM during the battle.

Check RAM via:

Game panel dashboard
In-game: /spark heapsummary

Too little RAM?

Upgrade your package via https://mijn.etheron.nl
Or: Lower simulation-distance further

CPU bottleneck

The Dragon AI is single-threaded and CPU-intensive.

Check with Spark profiler:

Install the Spark plugin
Start profiling: /spark profiler start
Fight Dragon for 2-3 minutes
Stop profiling: /spark profiler stop
Analyze the URL: Look at "Tick" percentage of EnderDragon.aiStep()

If Dragon uses >30% of tick time:

Consider lowering Dragon health with a datapack
Or use a plugin for simplified Dragon AI

Common problems

"TPS is 20 but Dragon still responds slowly"

This is likely an MSPT (milliseconds per tick) problem:

Check /spark tps → look at MSPT value
If MSPT >45ms: Ticks are being "skipped" internally
Solution: Follow structural optimizations above

"Server crashes during Dragon fight"

Crash logs can be found in the game panel under the logs section.

Common causes:

OutOfMemoryError: Too little RAM → upgrade or optimize
Watchdog crash: Tick took >60 seconds → lower simulation-distance drastically
Plugin conflict: Disable plugins and test incrementally

"Dragon doesn't regenerate via End Crystals"

Not a lag problem, but a game mechanic bug in some versions.

Fix:

/data merge entity @e[type=end_crystal,limit=1,sort=nearest] {BeamTarget:{X:0,Y:128,Z:0}}

Ensures crystals beam to Dragon portal pillar.

Monitoring during fight

Use these commands to follow live performance:

/spark tps  # Check every 30 seconds
/spark tickmonitoringstart  # Warns of long ticks
/minecraft:debug start  # Vanilla profiling (stop after 10 sec)

Target values:

TPS: 19-20
MSPT: <45ms
RAM usage: <80% of total

Preventive measures

Pre-fight checklist:

Server restart
/kill @e[type=item] (remove dropped items)
Ensure <15 players in End simultaneously
Disable non-essential plugins temporarily

Post-fight cleanup:

/execute in minecraft:the_end run kill @e[type=item]
/execute in minecraft:the_end run kill @e[type=experience_orb]

Scheduled restarts:

Set daily restarts at 4:00 AM via the game panel to prevent memory leaks.

Final note

If no optimization helps and your server continues to lag during Dragon fights, contact Etheron support via https://mijn.etheron.nl with:

Your server package details
Spark profiler URL from during fight
Number of concurrent players during fight
Minecraft version and server software

They may be able to apply backend optimizations or discuss hardware upgrade options.

Need help? Contact us via support.etheron.nl