Minecraft Forums

I originally posted this in a thread discussing server crashing and skipped ticks.

Enough positive feedback has been received that I think this fix should be made a thread of it's own.
This is not a fix for everything and every situation, but if your server was working, then suddenly wasn't after upgrading- GIVE THIS A TRY.

Symptoms reported:

• Chunks would not render in background regardless of client's settings.
• "It's not actually lag but it feels like lag" when walking or running. Player was on LAN connection which ruled out network connectivity. Most noticeable on horses or railways.
• Breaking blocks has a delay to disappear. May disappear and then reappear on player's client. Reported as "Blocks are not breaking all the time and sometimes disappear. I can break a row of ten dirt but only be able to pick up seven."
• "This is completely unplayable. I am so frustrated I am going outside to mow an acre of lawn."

Cause:

• Upgrading the server to 1.8

Server Symptoms:

• Server logged many [Server thread/WARN] messages whereas NONE were logged before upgrading to 1.8
• CPU use maxed out on all cores. More specifically Java.exe (or the Javaw.exe) process taxes the CPU even with no players connected, and spikes between consuming 65% and 99% of the CPU.
• Java would not correctly allocate memory, ie: Allocate a gig, only 256mb would be used.

Resolution:

• Edited the script that starts the server to include the nogui option at the end of the execute Java command.
• Link to Minecraft Forum's tutorial for a simple server start script

Personal Notes:
This solution took care of the CPU usage issue, chunks started rendering again, and all the "lag" disappeared.
The only thing notable is that the GUI will not load and administration commands will have to be executed from the CLI window that opens with the script. NOT LIKE THAT REALLY MATTERS given that the GUI has been broke since previous updates, lacking the resource monitor and log summary.

DO NOT DOWNGRADE YOUR SERVER IF THE WORLD HAS ALREADY CONVERTED TO 1.8. DOWNGRADING IS NEVER A GOOD IDEA.
Players will lose ALL inventory items and ALL chests will be empty.

I can not stress enough that there was no changes made to the host server other than running 1.8.
Changing the systems JRE did not make any difference.
Attempting to allocate up to 4GB of RAM did not make any difference.
There was no reason to suspect the CPU of needing an upgrade, as it worked with 1.7.10 just fine.

Final Thought:
Hope this helps.

Quote from Tapsa78»

Hi.

Internet connection is not an issue, as the server is hosted by Hetzner and is in a decent datacenter. Connection speed should be up to 500Mps both ways and I've confirmed this with speedtest.net.

I realized that one thing that I didn't check at first is the startup command for the server. The batch file and the command is something I built for Bukkit years ago so might not be best for a new Vanilla server. I took a look at the wiki and modified the command to this:


What I did was add the -d64 and removed a -Incgc parameter. This seemed to improve the situation a bit as now there was not a trace of lag with just two players. Earlier there occasionally was small lag even with a single player on the server. I'll have to wait until the evening when people usually come online to get a proper stress test. If someone has any comments about the start command please share.

I had very similar issues, lost my mind, and proceeded to write an over-descriptive post in another thread.
I know you're running the jar and not the Windows executable, but add the nogui option to your startup script.
That has been working for others running the exe. Let me know if it does your jar setup any good.

Server running minecraft.exe 1.8 FIXED

I've been spending the past 6 hours trying to figure out what's wrong with my personal Minecraft Server, and only found this thread AFTER concluding that the problems my players are reporting are directly caused by updating to the server to 1.8 last week.

Symptoms reported:

• Chunks would not render in background regardless of client's settings.
• "It's not actually lag but it feels like lag" when walking or running. Player was on LAN connection which ruled out network connectivity. Most noticeable on horses or railways.
• Breaking blocks has a delay to disappear. May disappear and then reappear on player's client. Reported as "Blocks are not breaking all the time and sometimes disappear. I can break a row of ten dirt but only be able to pick up seven."
• "This is completely unplayable. I am so frustrated I am going outside to mow an acre of lawn."

Cause:

• Upgrading the server to 1.8

Server Symptoms:

• Server logged many [Server thread/WARN] messages whereas NONE were logged before upgrading to 1.8
• CPU use maxed out on all cores. More specifically Java.exe (or the Javaw.exe) process taxes the CPU even with no players connected, and spikes between consuming 65% and 99% of the CPU.
• Java would not correctly allocate memory, ie: Allocate a gig, only 256mb would be used.

Resolution:

• Edited the script that starts the server to include the nogui option at the end of the execute Java command.
• Link to Minecraft Forum's tutorial for a simple server start script

Personal Notes:
This solution took care of the CPU usage issue, chunks started rendering again, and all the "lag" disappeared.
The only thing notable is that the GUI will not load and administration commands will have to be executed from the CLI window that opens with the script. NOT LIKE THAT REALLY MATTERS given that the GUI has been broke since previous updates, lacking the resource monitor and log summary.

DO NOT DOWNGRADE YOUR SERVER IF THE WORLD HAS ALREADY CONVERTED TO 1.8. DOWNGRADING IS NEVER A GOOD IDEA.
Players will lose ALL inventory items and ALL chests will be empty.

I can not stress enough that there was no changes made to the host server other than running 1.8.
Changing the systems JRE did not make any difference.
Attempting to allocate up to 4GB of RAM did not make any difference.
There was no reason to suspect the CPU of needing an upgrade, as it worked with 1.7.10 just fine.

Final Thought:
I hope this write up helps someone else running the Windows executable of Minecraft Server.

The title should explain pretty well but let me go a bit in depth. I have two modems, and two separate networks in my house hold. One of which houses my computer and my server that i have mine craft running on. It's a Motorola modem and a trendnet router. It port forwards just fine and i can get on the sever if I am on my other network. My other network is a Motorola modem and a linksys router. If i connect any of my computers to the 2nd network the connection to the server is a success, if i use my first network, the connection fails. What am I missing here? (if i switch both routers in each network with each other, i know the linksys one will allow me to, however if someone knows the problem besides doing that it would be much appreciated)

EDIT: Please find included this highly detailed diagram to further explain my situation

DOUBLE EDIT: Solved my own problem by using the local IP address instead of the external. A little annoyed that it must be done that way though. Is there a solution to that?