Minecraft Server Memory Leak

[Ajb]

I didn’t really know how to title this Topic, anyways I’m having quite a problem with one of my rather large Minecraft Servers lately, the server used to run fine for 1-4 days without needing a reboot, now after 4-6 hours it requires a Reboot because the Memory for the Minecraft Server is using all of it’s 8 Gigs, so I suspect it is as a Memory Leak. It’s a Towny Server, with around ~100 plugins, however I do have quite a bit of fairly large plugins, like Towny, mcMMO, Slimefun, Magic, Crackshot, I can send you a list of them if you’d like. If I can recall, the memory leak just started happening about 7-14 days ago, it seemed to happen after I installed/updated some plugins, I’ve removed some that I thought could have been causing it, but this memory issue keeps happening. Currently I’m on my Server alone, at spawn, no other chunks loaded, and this is what I see from /lag : https://gyazo.com/d35e9f53ea6f70d25f13353b73540375 - almost half the ram for the mc server is being used just from myself at spawn. Any help/suggestions would be greatly appreciated!

Thanks in Advance!

[iMelsom]

@hexparrot have commented issues like this on several occations, the lates one here:

Scheduled archives a ticking time bomb

There’s no such thing as ‘saving to RAM’. All functions in MineOS–all of them–save to the filesystem. Likewise, when you make backups (“restore points”), they save to /var/games/backup/servername. Java at times can seem bad at housekeeping, but actually more often it’s Minecraft/mods’ fault for leaking memory; the amount of work put in to making Java work properly absolutely dwarfs the amount of time and effort put into testing Minecraft and third-player mods. One other thing…sometimes th…

How linux and Minecraft treats RAM has also been discussed here:

Overtime, RAM goes away?

I wouldn’t make that generalization, no. But the site I linked you to tells you about “top” which will help you–in your specific case–determine whether or not the memory is cached or whether it is free. If it truly isn’t free, then starting a server will do no good. It could just as well be that your other server leaked memory and it is lost (and you need to restart your host). We can’t tell, merely with the information 170mb, so you’ll have to look it up a bit.

The first thing to remember is that how the minecraft servers them selves work, is not under MineOS and the WebUI’s control. MineOS and it’s WebUI only provides a frontend and a easy environment to mangae and run the servers. I think you would be better off asking a forum spesific to your server type for help with this. We will try our best to help you, but our knowledge of all the different servers, and the myriad of more or less homebrewed mods and plugins, is spotty at best.

A second thing to remember is that the larger a server is, the more memory it needs.

My best recomendation right now is to disable all mods, then see if the problem persists.

You can also try to start the server, then run the following commands in SSH:
You can both check ram and clear it with these commands:
free -m sync echo 3 > /proc/sys/vm/drop_caches free -m

This lists all memory (used and available) on your linux machine, then clears all used cache, then lists memory again. If the first command (free -m) do not reveal low memory I would not worry.

If all else fails: Add more memory, and let Minecraft have more memory to play with.

[hexparrot]

@Ajb

almost half the ram for the mc server is being used just from myself at spawn.

Question: if you’re okay allocating 7282 MB of RAM to Minecraft, why would you want Minecraft using any less than that?

Good performance comes from Minecraft having and utilizing lots of available RAM, not from having and reserving unused RAM.

[tNt]

I will chip in here as well, and give a report of 294 Stable Hours on MIneOS server with 70+ mods and 3 users. This is the custom server my girls requested and with the update to Jessie and Java 8, WOW. Also I have a FTBInfinity server running on the same hardware over 40 hours without a crash. It has alot of mods (150?) and it has not crashed.

So stable now. On the hardware side I allocate 1GB over what I issue the server. That means I give MineOS 4gb to play with but the server running it gets 5gb of total ram. This is for both servers at the same time. I know I can also run more at the same time but I have no need.

Of note is also the design of Minecraft itself for a single thread processor. Look it up. Hyper-threading actually degrades performance. I do cheat and issue 2 threads as I also issue two sockets as in processors.

My point in this thread is the same as Sir Hexparrot. (See what I did there? hexparrot is hereby Knighted Sir Hexparrot!) Mincraft is a RAM HOG but 4gb should be plenty for a few friends but if you want to invite the whole neighborhood you better get some serious hardware.

Thanks for your kind attention.

tNt