Server tick-lag skyrockets once a player joins with Distant Horizons installed.

Distant Horizons is installed on the server. Once a player with Distant Horizons joins, the server immediately begins to lag and stutter. My best guess is that this is from the server trying to send the player LODs. I have tried multiple different combinations of mods on the server, and this only happens when Distant Horizons is installed and a player joins with it installed as well. The Distant Horizons config has not been touched and is default on the server, as well as on the client.

Some quick info:

MC version [1.20.1]
Distant Horizons version [1.20.1 Beta 2.3.0 forge/fabric]
Forge version [47.3.27]
Using a server host, not self-hosting
14 GB of ram
6 CPU cores

"Logs":
Check attached file.

"Specific error messages":
Not really getting any error messages, other than "Can't keep up! Is the server overloaded? Running [X]ms or [Y] ticks behind" being sent to the console often.

"Your mod list":
Pastebin link or check attached file.

"Multiplayer or Singleplayer?":
Multiplayer.

SPOILER_Client_modlist.txt10.59KB

Server_log.log385.61KB

Pastebin

- achiopt 1.0.5 - advancementplaques 1.6.9 - aggroindicator 1.1.2+...

Pastebin.com is the number one paste tool since 2002. Pastebin is a website where you can store text online for a set period of time.

Mr•3/20/25, 3:08 AM

14 gb of ram is lowkey an insane amount, try lowering it to 4-5.

Mr•3/20/25, 3:10 AM

seeing as how many mods you have, try 5, if not 6. 14 is going to absolutely tank

Mr•3/20/25, 3:10 AM

It will specifically help with

Not really getting any error messages, other than "Can't keep up! Is the server overloaded? Running [X]ms or [Y] ticks behind" being sent to the console often.

Mr•3/20/25, 3:10 AM

@OhDuffo

OhDuffoOP•3/20/25, 3:12 AM

Wait, I don't mean to ask this in a rude way or anything, but lowering my ram will stop Distant Horizons from tanking my server?

Mr•3/20/25, 3:12 AM

I'm kind of suspecting that distantt horizons is not the thing causing your server to lag

Mr•3/20/25, 3:12 AM

14 gb is absolutely enough to cause server lag

Mr•3/20/25, 3:13 AM

it seems like it would be so that more=better performance

Mr•3/20/25, 3:13 AM

the way servers work is they will use as much ram as you give it, to the very last bit. so giving the server 14 gb isnt exactly giivng it 14 gb to work with, your basically telling it to use 14 gb ALL the time

Mr•3/20/25, 3:14 AM

it causes lag because your server is basically trying to manage, keep track of, and organize 14 gb of ram the whole time, as well as run the server normally

Mr•3/20/25, 3:16 AM

Try lowering it first, if that doesnt work install the mod spark, and run the command "/spark profiler start" and let it run in the backgroun while your server is up for a bit, 5 minutes is fine, then run "/spark profiler stop" it'll send a message with a link, go to it, then send it here.

https://www.curseforge.com/minecraft/mc-mods/spark

CurseForge

spark

spark is a performance profiler for Minecraft clients, servers and proxies.
115.7M Downloads | Mods

Mr•3/20/25, 3:23 AM

@OhDuffo any luck?

OhDuffoOP•3/20/25, 3:24 AM

That's actually a lot of really good information! I'll be trying this stuff out tomorrow for sure. Thank you! I'll come back with an update then!

Mr•3/20/25, 3:25 AM

Miki_P98•3/20/25, 6:34 AM

If what’s already suggested won’t work you can try decreasing the server side DH bandwidth limit and CPU load

Mr•3/21/25, 7:10 PM

@OhDuffo Hey! Any update?

MMr @OhDuffo Hey! Any update?

Tenou•3/21/25, 8:11 PM

I'd like to chime in here, as I'm experiencing the same issue. Setting to true leads to immense lag on the server. Disabling it immediately fixes this.
I'm hoping we have a common issue here and hence didn't want to start a new thread, which might cause us to do double work.

Attached is:
Spark profile with : https://spark.lucko.me/2r3mUaLNRm
Spark profile with : https://spark.lucko.me/vAITXXBqfg

These two reports have been started immediately after restarting the server after enabling or disabling the respective config, with two players online in the first report, only one in the second.

My server runs on my own hardware and has currently eight CPU cores (7950X3D) and 12GiB of memory assigned. This is only temporarily so high to rule out a bottleneck from it. The server is running great with two cores and 4GB of memory (ignoring DH).

Installed are only Chunky, dynmap & PlaceholderAPI as plugins.

Miki_P98•3/21/25, 8:12 PM

If you want both LODs and vanilla chunks using only DH to pregen both is faster and doesn't have the issues of using Chunky with DH

Tenou•3/21/25, 8:13 PM

Chunky is only still installed from when the server was originally created; it's not currently used to generate anything anymore

Tenou•3/21/25, 8:13 PM

That is really good to know though

Mr•3/21/25, 8:15 PM

@Tenou Unless you absolutely know that your server should be using 12 gb, I highly highly reccomend lowering it, especially from the profiler it doesn't look like you are using any mods. I run a server with 100+ mods on it, distant horizons included, and am able to sustain 8 players with no lag at all with just 5 gb assignned

MMr @Tenou Unless you absolutely know that your server should be using 12 gb, I high...

Tenou•3/21/25, 8:17 PM

Yeah it was only on 12 to test if that changes anything. It was previously on 4GB (is now on 4GB again), the issues were the same

Mr•3/21/25, 8:17 PM

Are you getting the "Can't keep up! Is the server overloaded? Running [X]ms or [Y] ticks behind" in the console?

Tenou•3/21/25, 8:17 PM

Yes

Mr•3/21/25, 8:18 PM

What was the command you ran to start the spark profiler in your server exactly? if you can remember

Tenou•3/21/25, 8:18 PM

I can provide you with the full log of that session, if it helps

Tenou•3/21/25, 8:22 PM

Here you go, whether you want it or not :pepe_feelskek2:

2025-03-21-6.log15.64KB

Mr•3/21/25, 8:26 PM

Weird question, linux server's operating system @Tenou

Mr•3/21/25, 8:28 PM

is it mint?

Tenou•3/21/25, 8:32 PM

It is not

Tenou•3/21/25, 8:32 PM

Iirc it should be Ubuntu Server

Tenou•3/21/25, 8:32 PM

Virtualized within PVE

MMr is it mint?

Tenou•3/21/25, 8:44 PM

Why the specific question after mint?

TTenou Why the specific question after mint?

Mr•3/21/25, 8:47 PM

I'm reading into your profiler right now, and having a hard time pinpointing the source of the lag because spark is seeing that things are "waiting" which is what theyre meant to do

Mr•3/21/25, 8:48 PM

Just asking because I'm reading into it and just trying to think about what could be causing the lag

Mr•3/21/25, 8:48 PM

I do think you are correct that it is actually disttant horizons causing the lag

Mr•3/21/25, 8:48 PM

The issue is that it shouldnt be

Mr•3/21/25, 8:49 PM

I'm just gonna spitfire my ideas at you,

Mr•3/21/25, 8:49 PM

Have you tried this on a different world? As in deleting the current world folder and running the server again to let it regenerate

Mr•3/21/25, 8:53 PM

Also, if I were you I'd try a fresh install of java just because it cannot hurt

Mr•3/21/25, 8:55 PM

I just use openjdk

Mr•3/21/25, 8:56 PM

As well as just upgrading and updating your system and

Mr•3/21/25, 8:59 PM

Hopefully these can help in some way, but in your server thread you can see that the bukkit chunk load is definitley causing some issues

MMr The issue is that it shouldnt be

Tenou•3/21/25, 9:01 PM

Good to see we aggree on that :kek:

MMr Have you tried this on a different world? As in deleting the current world folde...

Tenou•3/21/25, 9:02 PM

I have not yet, no!

Tenou•3/21/25, 9:02 PM

I'd be happy to give it a shot, just can't promise it right away

Mr•3/21/25, 9:02 PM

Understandable lol

Mr•3/21/25, 9:03 PM

If the umbrella solutions I provided don't work, I would think about trying to host without any plugins and see