Questions: Recommended RAM allocation and "Read timed out"

Hey, dear bukkit community.

I got myself a new dedicated server again (i7 980-X 3.33-3.6GHz; 24 GB DDR3-RAM; 120GB SSD; ...)
Most of the time I have around 20-50 users online at the same time. I run a lot of plugins and the server runs 5 worlds (freebuild, survival, roleplay, nether, skylands).

The server if fully dedicated to Minecraft and the operating system itself together with all enabled services (such as mysql) never take more RAM than ~500 MB... So I wondered if it's okay and smart to allocate 22-23 GB RAM to the java process (bukkit).

Our server is currently suffering from read timed out errors... We've had them since a long time but they occur very often since a few days. As I mentioned above, we were on a much weaker server a few days ago and with the switch, we took the problem with us. So it's definitely software related. We added a skylands world a few days ago and that's actually when it became really mad.

The server itself runs without lags, everything's smooth and then - suddenly - it locks up, everyone gets kicked out with a "Read Timed Out" exception message and the server locks up, printing "Read Timed Out" over and over in the console. It won't react to any console commands and the only way to shut it down is to forcefully kill it.

Our partner server has exactly the same problems on a different machine with mostly different plugins. The strange thing is: Sometimes, our servers crash simultaneously (almost). In the past, we had IPs such as 178.63.17.22 losing connection from our server... If you enter it in a web browser, you get redirected to a polish page which is run on a german hetzner server. I googled it and the guys behind this IP are also known for spamming guest books and defacing websites. 2 weeks ago, the read timed out crashes stopped for a while after blocking these IPs. In 1.4 times, there was an exploit in bukkit that allowed "hackers" to send an invalid packet to the server to crash it (.crash command). Could it be possible that this is the case again?


1. What OS are you using (Brand and version - Ex. Windows XP SP3)?
2. What architecture is the OS you are running (x64 or x86)?
Ubuntu 11.04 minimal
Linux Ubuntu-1104-natty-64-minimal 2.6.38-8-server #42-Ubuntu SMP Mon Apr 11 03:49:04 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

3. What version and architecture is your java install? (Type: java -version in command prompt.)
java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

4. Are you running any wrappers? McMyAdmin, mcadmin, Hamachi, etc?
Yes! We're using my own nBukkit wrapper. But it doesn't mess around with network packets, it's just sending save-all every 30 minutes and then it creates a backup of all worlds.

5. What build of CraftBukkit are you running? (do NOT say latest. Say the build number.)
The build number is displayed in the top of the server.log.
#953

6. What command are you using to run your CraftBukkit server?
Currenty, I use "java -Xincgc -Xmx23G -jar craftbukkit.jar" to start the server. I've been using more fancy commands which can be found here, for example. But it didn't make that much difference.

7. What plugins are you running?

• AuthDB
• BananaMapRender
• BorderGuard
• BukkitContrib
• BukkitHTTPD
• ColoredSigns
• CommandBook
• FalseBookBlock
• FalseBookCore
• FalseBookIC
• HeroChat
• HeroicRebuke
• iConomy
• iConomy ChestShop
• LightningBox (self-made AFK plugin)
• LogBlock
• LogBlock Questioner
• LWC
• mcMMO
• Minecart Mania
• Minecart Mania Sign Commands
• Minequery
• MobBounty
• MultiVerse
• MyHome
• MyWarp
• NaturalGiants
• NoSpawn
• NoWeather
• OpenInv
• Permissions
• properTime
• SeriousCommands (self-made generals plugin, going to replace CommandBook)
• Towny
• UnitedWeStand (self-made kick/ban/whitelist solution)
• Vanilla
• VanishNoPickup
• Votifier
• WorldEdit
• WorldGuard

8. What error are you getting (post your server.log file)?

Sometimes, it happens right after somebody logs in. But not always. But it always shows "Connection reset" and then it crashes.

9. What have you tried already?

• Switched operating system (CentOS 5.x -> Ubuntu 11.04; both x64)
• Rewrote all config files from scratch
• Tried OpenJDK, official JRE 1.6, official JRE 1.7 (all x64)
• Tried without wrapper
• Tried many different craftBukkit versions
• Tried many differend java garbage collection flags and things like that
• Yesterday, I spent the entire day to troubleshoot the problem by removing one plugin after another after each crash... I already tried to remove every plugin not necessarily needed
• Disabled the skylands world
• Tried Chunkster (0 errors) to check if the world files are corrupt
• Removed all entities from all worlds
• Deleted all player.dat files
• New world (single world)
• ...

10. Have you tried any of the things below?
1.) Run the vanilla Minecraft server (no Craftbukkit). Does the error/problem still occur?
No, I didn't try that. But I'm going to if the problem persists.
2.) Update your CraftBukkit Build. A newer version may have fixed the error.
I always run bleeding edge software.
3.) Remove all your plugins and try with just CraftBukkit. Does the error/problem still occur?
The operators of our partner server are trying that right now. I will do it as well.
4.) Add in a single plugin. Does the error/problem still occur? If yes, post on the thread of the plugin itself.
As I said, we did it the other way: Removed plugins one after another.

I'm sorry for any grammar mistakes in the text. So, what are your thoughts? Any help?
- Netto

 

this sounds like the same issue that we have in this thread

http://forums.bukkit.org/threads/error-help.13280/

its almost identical to my problem its just you have a much faster server than me

 

Yep, it's very confusing.

 

are you also having the sky rubber banding issue? where for instance the sun will move along a bit then snap back in to place if you haven't noticed it watch the sun on your server for a min or so and see if it happens

 

I've had it on my old server, yes. It started to occur when 15+ players were on the server. It's not occuring at all on the new server.

I recommend using properTime to cure the lag produced by this issue.

 

This is an MCMMO plugin issue. Once you disable MCMMO the problem will go away. I've been talking with the plugin dev and he's looking into it. But its clear he doesn't know what it is eactly. I would recommend posting on his form and PM him the info that he requested for this bug.

http://forums.bukkit.org/threads/rp...d-multi-lingual-953.3505/page-148#post-444834

 

I'm going to try it without mcMMO tomorrow. I really hope this will fix the issue, it's very annoying. However, this would mean I'll have to shut down my roleplay world. Any suggestions for a working alternative to mcMMO? I don't mind writing a script to convert the old database to a new format.

Anyways, thanks for your reply.

 

I'm in the same boat here. MCMMO is the best one out there that I know of.

 

Well, I just read through the mcMMO thread and some user recommended to downgrade to Permissions 3.1.5... And as I think of it, it started crashing that often when I upgraded Permissions to version 3.1.6...

Well, I just downgraded and now let's see if it works or not. I'll have to wait until tomorrow, the server never crashed at night before.

 

Please let me know if that fixes the problem. Ty!

 

I have the same problem
The server stop responding, and 2 of my cpu core is full
I never use mcMMO but I installed Permissions 3.1.6
I tried to set -Xmx1000M then no getting read time out anymore
but i get 40+ players online. 1G memory is not enough

 

My server also freezes.
Thinking when I use Permissions 3.1.6 (havent got this error with 3.1.5 downgrade, but some other nullpointers -.-)

 

I think, there's a lot of hard work in Permissions 3.x But also an awful lot of bugs to fix. -.-

 

Netto Hikari - Please let me know if downgrading Permission fixes your problem. Ty

 

Yup, the problem is fixed. However, some plugins permissions don't work properly. But that's a minor issue.

 

ty, will downgrade today!