(taken straight from my reddit post...logging as a bug because I've never seen this in a server before although I would really just like to know how to find out what is causing the lag)
I recently started up a home multiplayer server for my family.
We haven't really gotten too far in the game (haven't been to the nether even) so there isn't much around spawn, yet the server is very laggy. We have 24 animals near the base (chickens, cows, pigs and sheep) but I've culled it from 40 of each type, and it made no difference.
There is a pillager outpost very close however, and I blame it for the nearly on the dot 5 minute huge lag increase...but not the smaller lag spikes.
It starts off 40 ticks behind before anyone logs in, and even with just one person on, the server console window shows the ticks behind increasing every 20-30 seconds. After 10 or so minutes the ticks behind is over 200 and still increasing.
I have another server that we've been on since 2016, and the only time it lags is when I'm near a 256 sheep farm and 200+ animal "tower"...with redstone stuff all round spawn....so I just don't get why the new world is so bad. Both are hosted on the same computer, but only one runs at a time, however the computer is capable of running 3 concurrent minecraft servers hosting 4 people each without many issues.
Is there a way to determine what is causing the lag?
This is the seed: -5177762073143313782 (be careful in survival, the spawn point is within spawning distance of the pillager outpost)
Here is an example of what I'm seeing just standing in the forest inside a house.
The command to load the server is:
"C:\ProgramData\Oracle\Java\javapath\java.exe" -Xmx8G -Xmn2048M -jar "C:\Games\Minecraft\ServerJar\server1.14.4.jar" nogui
[14:06:08] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2013ms or 40 ticks behind
[14:06:43] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2009ms or 40 ticks behind
[14:07:05] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2001ms or 40 ticks behind
[14:07:22] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2289ms or 45 ticks behind
[14:07:41] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2005ms or 40 ticks behind
[14:07:59] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2301ms or 46 ticks behind
[14:08:16] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 2765ms or 55 ticks behind
[14:08:34] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 3065ms or 61 ticks behind
[14:08:53] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 3448ms or 68 ticks behind
[14:09:12] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 4065ms or 81 ticks behind
[14:09:31] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 4469ms or 89 ticks behind
[14:09:51] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 4923ms or 98 ticks behind
[14:10:12] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 5248ms or 104 ticks behind
[14:10:33] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 6182ms or 123 ticks behind
Comments 6
Seems to be related to mob AI or similar.
Set the difficulty to peaceful and back to hard...stopped the increasing lag issue.
We do not have enough information to find the cause of this issue.
Please run /debug start, wait a while and then run /debug stop. Afterwards, run /debug report.
If you do not have the permission to run these commands, open your world to LAN and enable cheats. If you're on a server, make sure that you're a server operator in order to execute these commands.
Then, please attach the profile results found in debug/profile-results-<DATE>.txt, as well as the debug report found in debug/debug-report-<DATE>.zip here.
This issue has been temporarily closed as Awaiting Response. Once the requested information has been delivered, the report will be reopened automatically.
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yeah close it mate.
I can't replicate the issue properly after removing all the enemy mobs by setting the difficulty to peaceful and back to hard.
I would really like to know how to pinpoint lag in the game though...
By doing what I posted in my comment above, you can find out where exactly the lag is coming from. Hence I asked you to attach those files to this ticket.
@GoldilokZ you're possibly experiencing MC-157697 which has very particular conditions, so tricky to reproduce without knowing but they're ones that happen naturally quite often.
Please do not mark unreleased versions as affected.
You don't have access to them yet.