Very weird OutOfMemory error

Hello, every once and a while after the server has been running for a while this weird error pops up.

http://pastebin.com/t7CTFNA5

All the java version etc are in that pastebin. Any clues / help?

 

Allow the server to use more RAM; cannot create new thread; needs more RAM.

 

You are most likely not allocating enough RAM for it to save certain files

 

Yep, running out of memory it seems.

Increase the limit or try to find if there is a plugin leaking RAM.

 

None of the above are the case, if you would direct your attention to the free -m results.

Also, 5GB should be more then enough. There's only 20 players on.

 

That's odd. It's basically saying something to do with starting a thread is sucking up so much memory.

 

Would it have something to do with the processor?
Threads are related to cores etc, am I right?

 

A type of client-side hack can cause this! Can't remember which though, could be spamming the 254GetInfo packet...

LE: Yep, it is! 15:09:56 [SEVERE] at net.minecraft.server.Packet254GetInfo.handle(SourceFile:16)

Someone is just spamming that packet, until the server runs out of memory!

 

Interesting. I will investigate this later.

 

I got something like this on my old server and they said something was sending million bytes to the hard drive and caused lag and that...

 

It's a client-side issue. Someone on your server is trying to shut down your server. Intentionally.
As ZNickq said, look at this part of the error:

Code:

[SIZE=12px][FONT=Consolas][COLOR=#000000]15:09:56 [SEVERE] at net.minecraft.server.Packet254GetInfo.handle(SourceFile:16)[/COLOR][/FONT][/SIZE]
[SIZE=12px][FONT=Consolas][COLOR=#000000]

[/COLOR][/FONT][/SIZE]
Someone's trying to spam that packet with information.

 

Hm, I've found the code https://github.com/Bukkit/CraftBukk...net/minecraft/server/NetworkManager.java#L244

Not sure how to prevent this though?

 

The way the message is worded implies to me it's not literally out of memory, it's out of native threads, which for some reason throws the same exception. Apparently that specific packet always starts a new thread so if it's spammed you run out of threads. Worth an anti-hack look-at, I suppose.

 

This started happening after the switch from apache to nginx. I've removed nginx and I am using apache now. Will see if this helps at all over the coming days.

After switching to apache I have yet to see this error happen. Will update if I see it again!

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Peskey client hackers...
If it's a bug then we ought to fix it with the next RB.

 

Still getting this error unfortunately

 

Figured it out! Here's the bug report that helped: https://bugs.launchpad.net/ubuntu/+source/php5/+bug/876387

I noticed this error was happening every half hour on the 9 and 39 minute mark. So it made sense it had something to do with cron.

Low and behold, changing /etc/cron.d/php5 to the version in Ubuntu 11.04 fixed it!