Lag on powerful machine: what is the problem?

Discussion in 'Bukkit Help' started by FrancescoTG, Aug 31, 2012.

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    Hi all!
    Recently I created a bukkit server on a machine, but I experience some lag.
    - 2x CPU Intel Xeon Dual Core 3.40 Ghz (2 +2= 4 COres
    - 1 HDD SATA 250 GB Seagate Barracuda 7200 RPM
    - 4GB RAM DDR2 667 Mhz
    - CoolerMaster Power Supply 620 Watt
    - Asus NCCH-DL Motherboard
    - 100Mbps Download
    - 50Mbps Upload
    - MineOS CRUX 0.4.11e (a linux distro for Minecraft servers)
    - Java 7 Update 5
    - WebUI
    - SSH Server
    - Plugins list (37):
    When there are 5/6 players online, I experience only a few lag. But, when there are about 14 players, I get a response for any command I send after 4/5 seconds and the server lags a lot.
    Besides, after 30 minutes that the server is on, all the machine begins to lag: from the SSH connections to Bukkit. After rebooting, the machine works perfectly.

    It's very strange, because the server is quite powerful, like the connection.

    What can I do?

    Thanks in advance for help. :D XD

    P.S.= In the bukkit start command I specified to use 4096 and 8 cores (2*2*2)
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    Are there any errors in the console? Also, 4GB RAM is not that much. It all depends on how many plugins you have/worlds... etc. You might want to switch to a SSD as well.
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    Maybe try to lower the amount of RAM you give the java process to, say, 3500M or 3000M?
    It might be that the machine starts to lag if the java process actually uses ALL of the RAM thus leaving none to other programs. That will effectively kill your machine regardless of the specs.
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    Thanks for your reply, but I can't see any error via console.
    Here you the plugins list (37):

    Thank you, I'll try it, but I have a question. If i reduce the allowed RAM for bukkit, will the server lag more?
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    That depends on the plugins in use, the number of players logged in etc. But if the java process uses all of your RAM and the OS needs to start swapping, it will lag the entire machine (ssh etc.). You should try to find out how much memory you need to reserve for other processes than java/Minecraft and then set the java max memory based on that. I guess my point is, it doesn't help if you get bukkit to "lag less (=have enough memory for itself)" if your whole server dies to a lack of free RAM.
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    Hello FrancescoTG, Maybe I can help. I see a few things here.

    Bandwidth: Your up and down look good, I assume they are business level and not a residential connection? In other words your not using a Cable or FiOS connection? They can be great connections for web browsing but they typically have big bandwidth to overcome their poor latency.
    Memory: You want about 1GB for your OS(linux fans will rage at me for this, but you will see a difference, dont do less as most linux zombies claim)and set up your craftbukkit to use the rest. You also have a slow memory speed at 667Mhz. If you can, get 8GB in there with800+Mhz(your motherboard can handle up 800Mhz so get at least 800-But I woudl recommend 1200+ FSB and memory). Then allocate only 6GB to minecraft.
    Harddrive: Looks just just OK, I would like faster rotation to reduce read time. But you also must remember seek time. When you formatted the drive, how much space did you allocate to each sector? I recommend doing the max your drive can handle. Your HD space fills up faster BUT your files are less broken up reducing your seek time.
    VirtualMemory: Now Im a little out of my element here cause your on a linux OS... BUT windows has something called Virtual Memory. Its temporary data qued up on the hard drive in a known sector of the drive that windows can go to and get information on. IF there is something similar to it in Linux, a good basic rule on systems that use this VMem system, Take your physical memory and multiply that by two. Then set your VMem to the resulting number.

    Well I spent more time typing that then I thought so I hope I helped. Cheers!
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    what version of NoCheatPlus are you running?
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    Offline-mode servers are not supported here (Since I see you use xAuth). Please turn online-mode=true and don't support piracy!
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    I use xAuth because two staffers have lost their accounts and they need to log using a different launcher that works only white online-mode= false servers. D:

    I'm running NoCheatPlus v.3.6.1 (the latest build) but that plugin doesn't start, because it's comaptible only whit 1.2.5 bukkit builds. I'll remove it! :D XD

    I tried to decrease RAM to 3550M, but bukkit and the machine have lag anyway. D:

    Thanks very very very very much for your very very helpful answer! :D XD
    1) I use an ethernet cable and the machine is placed in an office made to host servers.
    2) Ok, but two months ago I had a dedicated server whitout lag and the host company told me that the dedicated memory to bukkit was only 768MB. Should I have more RAM or faster RAM?
    3) I'm not understanding all you have wrote me about the HDD. How can I allocate much space to each sector?
    4) Are you talking about ReadyBoost? I don't think there is something similar on Linux... D:
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    Too bad, but it's against the rules. You won't get support here.
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    1) OK, but does the office have a professional internet connection. Who is the internet service provider?
    2) It depends. Check how much of the RAM is being used when you lag. If its maxed out with most of the allocated memory used up, its probably a plugin. But if there is little used and its laggy, its probably the speed.
    3)Here: See the comment from "MrLinux" in that post. He describes it well. Its during the formatting process(in otherwords you would need to format the HD again for that-Not that big of a deal if you ask me... just time consuming).
    4) Im not sure... I dont know linux. You will have to ask someone in a linux forum what the linux equivalent to virtual memory is like on windows.
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    Buy the game. Tell your friends to buy the game.
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