Problem CPU Spikes ~ FTB Infinity 3.0.2

[darkrisingx]

Unable to find the lag I believe the problem lays in java somewhere maybe someone can trace the issue down.

Sitting in the server just me not moving cpu spikes up and down and when it does the server lags waiting on it to go back down normally last for few seconds at 100% cpu in this time the server delays a lot and the server depending on how long the cpu is maxed will timeout the players. This cycle is endless spike timeout normal spike timeout normal.

Installed opis temorary to see if I could trace any issues down everything seems normal from opis.

TPS on the server looks normal solid 20tps 10ms.

Server specs:

CPU: Xeon E3-1240 v6 @ 3.70GHz ~ full core to myself
Ram: 4GB
OS: Ubuntu 14.04.5 LTS x64
SSD
Java: 1.8.0_151

Taken the same server copied to desktop server runs fine without cpu spikes solid as can be.

Pack installed is "Feed The Beast Infinity Evolved ~ version 3.0.2"

Nothing changed on the pack other then backups disabled and 1 mod added "PneumaticCraft".

 

[grandrolf]

~ full core to myself

Is this a virtual machine?

Is there other Minecraft servers (or other applications) running on the same machine?

 

[darkrisingx]

Currently the server does have other things on it. I have however tried re-installing the server back to untouched Ubuntu with just the mc server with same results.

It's a VPS not on the same pc. By full core to myself I don't mean 1 v-core shared with people. It's a dedicated core to myself.

Network on the server looks great along with ssd i/o.

 

[grandrolf]

It's a VPS not on the same pc

Is it a hosted VPS or do you have control over the base OS as well?

 

[darkrisingx]

Hosted server KVM environment.

 

[grandrolf]

2 possible things I can think off:

1 - The host (base os / physical machine), is set to force time sync on the virtual guests (the vps / virtual machines running). - This can cause major lag issues on a Minecraft server.

2 - The hoster have over allocated how many machines that has to fight for the available vCPU's on the hardware so that the guests have to wait for a empty cpu slot.

Taken the same server copied to desktop server runs fine without cpu spikes solid as can be.

This test that you did kind of supports theories of these nature.

My suggestion is that you contact the hosting company and have them sort it out, if they can't - change hoster.

 

[darkrisingx]

Time sync is off on the server. Tried the minecraft server on 2 other servers I had outside of the host i'm with now just for testing. Results from that was same cpu spiking just sitting in server endless loop of normal lag timeout.

#2 question i trust the provider i'm with server is only doing this with minecraft nothing else. Problem has to be with java or something in ubuntu 14.04 unsure as said above 2 other servers different ones same results.

Someone give me some java flags to try and cpu spikes seem to be gone. Sitting in server no spikes so now I have 3 people in server play still no spikes. So this is good progress.

Full boot he had me do with server no spikes with this:
-server -XX:+UseConcMarkSweepGC -XX:+DisableExplicitGC -XX:+UseAdaptiveGCBoundary -XX:MaxGCPauseMillis=500 -XX:-UseGCOverheadLimit -XX:SurvivorRatio=12 -Xnoclassgc -XX:UseSSE=3 -Xms512M -Xmx3072M -jar FTBServer-1.7.10-1614.jar nogui

 

[darkrisingx]

Server has decided to start spiking again. Was spiking and lagging out of world now this time seems to be just player inventory doing it / machines.

TPS is fine on the server when the lag happens.

Think i'm going to reinstall the server some time tonight and install the latest ubuntu server 16.04.3 and see what the results are.