mojira.dev
MC-97860

Severe performance issues in Minecraft server

There are still severe performance issues in the Minecraft server. When only one player is logged on to the server and the player are in specific areas of the world we get this all the time:
[09:14:47] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 5944ms behind, skipping 118 tick(s)
[09:15:04] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4674ms behind, skipping 93 tick(s)
[09:15:21] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 5025ms behind, skipping 100 tick(s)
[09:15:34] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 3079ms behind, skipping 61 tick(s)
[09:15:53] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4481ms behind, skipping 89 tick(s)
[09:16:10] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 3751ms behind, skipping 75 tick(s)
[09:16:24] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2267ms behind, skipping 45 tick(s)
[09:16:44] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 5615ms behind, skipping 112 tick(s)

Looking at the server load on an Ubuntu computer:
$ top -b -n 1 -d 10 -H | head -n 10
top - 09:18:02 up 40 days, 15:26, 3 users, load average: 1,00, 1,03, 0,88
Threads: 393 total, 3 running, 390 sleeping, 0 stopped, 0 zombie
%Cpu(s): 4,8 us, 0,1 sy, 0,0 ni, 95,0 id, 0,1 wa, 0,0 hi, 0,0 si, 0,0 st
KiB Mem: 4148312 total, 3866188 used, 282124 free, 125132 buffers
KiB Swap: 4192252 total, 213360 used, 3978892 free. 1179356 cached Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
30031 ne 20 0 2512884 2,218g 10744 R 98,9 56,1 1647:03 java
22266 ne 20 0 6784 2988 2532 R 6,2 0,1 0:00.01 top
30037 ne 20 0 2512884 2,218g 10744 S 6,2 56,1 5:54.50 java

The server thread is running at maximum of what the CPU can handle. This was not the case in 1.8.

The world can be downloaded here (1.5GB zip file):
https://drive.google.com/file/d/0B4TrJIjkwdYzdE16ZUp5UngtZlU/view?usp=sharing

A suitable spot to be at: /tp -140 100 740

Compared to 1.8 this is a huge performance drop. You may argue that we should have a faster CPU, but when the load was at 25% in 1.8 I cannot see that this performance drop is reasonable.

CPU on Ubuntu computer: Pentium(R) Dual-Core CPU E6600 @ 3.06GHz
CPU on Windows 10 computer: Intel Core i7-2600 @ 3.40GHz

The problem is the same on both these computers. Both computers are equipped with SSD disc.

Related issues

Comments

migrated

I have this same problem, not only that, but when no players are on in my server, it sometimes turns off on it's own, saying that the Java runtime exception, or something along those lines...

migrated

This is not a duplicate, nor is it a resolved issue! I can't run my server on any computer without it crashing when no players are on, so I can't have a dedicated server!

migrated

it is resolved as duplicate, and it's the same issue, go look over there

migrated

Sorry, originally it didn't seem the same, and another thing, I figured out why it's been crashing, it's not the server, it was simply because:

  • Either the world was created with custom world generation using the singleplayer world gen options

OR-

  • The world was made in a snapshot version

I'll check out the other post to see if that was resolved or not, but I'm wondering if there's a way to uncorrupt the world...

migrated

(Unassigned)

Unconfirmed

Minecraft 1.9 Pre-Release 2

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