Minecraft server package seems to be unstable?

[girish]

Fixed in https://git.cloudron.io/cloudron/minecraft-app/-/commit/6691478e868062801b5a5b13123437b2e4d7ab2b

[warg]

Can you apply the fixes for Forge as well please? Thanks!

[warg]

The fix is sadly not completely working. It does read the value without an error now but the value is wrong. I did set 4 GB of RAM for Forge and it did output this in the console:

Aug 09 21:05:18 Starting Forge Server with memory limit 3277M

So it looks like the wrong unit is used.

[nebulon]

Can you open a webterminal and read the vile /sys/fs/cgroup/memory/memory.limit_in_bytes to see how much the container actually got allocated in the end?

On Linux with docker containers have memory limits set with parts swap and physical memory (half half). So the memory limit calculation for Cloudron also takes this into account to prevent user error, without having to educate about the technical details much. Anyway those limits are upper limits and not reserved memory per app. Those act as a safety net to prevent a rouge app to bring down the whole server or also guide language runtimes like java/ruby/nodejs/... do not cache too much and run their garbage collectors more often. Essentially make them behave better in environments where they don't have the whole system on their own.

In Cloudron you can see the actual memory limit set in the backend calculated here: https://git.cloudron.io/cloudron/box/-/blob/master/src/system.js#L207

[warg]

@nebulon said in Minecraft server package seems to be unstable?:

Can you open a webterminal and read the vile /sys/fs/cgroup/memory/memory.limit_in_bytes to see how much the container actually got allocated in the end?

I don't find the file you have mentioned, neither in the container nor from the shell as root. There's a /sys/fs/cgroup/ directory and memory.* files in it but no memory.limit_in_bytes.

[girish]

I reworked the minecraft* apps to use a single code base now. The fixes are:

• oidc support
• memory limit computation (cgroup v2)
• duplicate log lines
• better log lines in the ui
• various other ui issues
• log history

Big thanks to @warg for all the bug reports. I have already fixed up the forge app, the other two will follow shortly today.

[warg]

Thank you for fixing all of this!

[warg]

Beside of the fixes and the Forge app and Minecraft app doing nothing (no players, new world so nothing automatically running, e. g. redstone stuff, no mods) + having plenty of free RAM, the server is unstable according to its logging:

Aug 10 12:05:57 [10:05:57] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 3277ms or 65 ticks behind
Aug 10 12:22:59 [10:22:59] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 6428ms or 128 ticks behind
Aug 10 12:36:09 [10:36:09] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 9279ms or 185 ticks behind
Aug 10 12:39:44 [10:39:44] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 11625ms or 232 ticks behind
Aug 10 20:48:30 [18:48:30] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 6541ms or 130 ticks behind
Aug 10 21:51:17 [19:51:17] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 12512ms or 250 ticks behind
Aug 10 21:58:43 [19:58:43] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 14030ms or 280 ticks behind
Aug 11 00:26:51 [22:26:51] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 8281ms or 165 ticks behind
Aug 11 04:43:37 [02:43:36] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 5874ms or 117 ticks behind
Aug 11 06:14:26 [04:14:26] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 3928ms or 78 ticks behind
Aug 11 06:30:14 [04:30:14] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 5482ms or 109 ticks behind
Aug 11 07:20:26 [05:20:26] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 11857ms or 237 ticks behind
Aug 11 09:04:06 [07:04:06] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 9322ms or 186 ticks behind
Aug 11 09:12:49 [07:12:49] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 25424ms or 508 ticks behind
Aug 11 09:22:43 [07:22:43] [Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Is the server overloaded? Running 4898ms or 97 ticks behind

Does someone else face this? What else could be the root cause here? I don't think it's related to any resource bottleneck.

[girish]

I noticed this as well. I assume this is related to too little memory or low CPU. Have you tried allocating much more RAM? I can test this later as well and maybe also change the default memory allocation.

[warg]

RAM is always idling between 1 and 2 GB while 4 is assigned. CPU should be fine too, at least I don't notice any performance issues or bottlenecks within the OS or other apps. The only other thing that is slow at the moment is Nextcloud 27.0.2 but that could be due to the latest update? Not sure. I will assign 8 GB RAM. Let's see.

[warg]

Nope, increasing it from 4 to 8 GB RAM didn't help. Seems something else is wrong.

[nebulon]

If not memory related, then disk I/O speeds and cpu could be a possible bottleneck? How is cpu utilization as shown with top or htop while the minecraft app is showing those message?