1.8 - Massive strain on the CPU?

Discussion in 'Bukkit Help' started by Zothen, Sep 18, 2011.

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  1. Offline

    Zothen

    Hello gentlebeings!

    We have a strange problem with our server!

    We run minecraft on a dedicted i7 920 (@2.66ghz/ 12GB RAM) hosted in a decent datacenter. The server runs Ubuntu and Java 7. The two MC servers run on an installed VPS with 10GB total, while the 2nd VPS runs only the website and TS3 server.

    The problem: Minecraft 1.8.x (bukkits included) causes a massive strain on the CPU related to 1.7.x.

    Values:
    We run 2 MC servers - each on a dedicated core with 4GB RAM associated.

    - The 1.7.3 server with CB1060 and a handful of plugins (e.g. BB) uses ~15-20% of the CPU with 15-20 players. This server can easily run approx 100 players.

    - The 1.8.x server without any plugins uses 50-70% of its CPU with 15-20 players and hits 100% CPU with approx 25-32 players (no world generation!)

    The server was monitored with top and vmstat over more than 5 days, so the given values are good averages! Also theres no change when the 1.8 server runs alone.

    What is going on here?
    1. Why is the 1.8 server code suddenly munching through server cycles like Pacman through magic pills?
    2. Why arent there more server admins reporting this issue? Is it related to our server or is it a general problem?
     
  2. Offline

    PunJedi

    Weve been running about 110-175 users, average of 10 hour runs at these loads. Here is what our Java tuner has told me.

    1. We run about 110% on our 8 core system
    2. We use a 10G heap out of 24G available.
    3. Jvm floor for GC is higher than usual but not ridiculous.

    Plugins running....

    1.8.1, Bukkit build 1149, General, iConomy 6, Chestshop, Worldguard, Worldedit, and a few others.

    The biggest issues we have so far is the variant lag between members.

    about 40 members will say "no lag, were fine" another 40 will be saying "omg LAAAAG"

    Over-all it seems more about MC's client side memory leaks than anything, and this could have carried over to server side a bit.

    Ramdrives, Tuning, and constant monitoring seem to be what it takes for now. Hope that helped a bit and good luck!
     
  3. Offline

    Zothen

    Yes, indeed thats good input!
    110% means that the CPU is overloaded so there will we lag for those players that the server cant handle at the moment! But also most players have no idea what "lag" acutally is and misuse the term for any problems they encounter! Most lag Ive reviewed was rather client performance issues than actual lag.
    Can you tell the the cpu spec for that machine, @PunJedi ?
     
  4. Offline

    Rockstar04

    110% could also mean that its linux and using more then one core.
     
  5. Offline

    Zothen

    no, mc cant use multiple cores - it says that the core is overloaded...
     
  6. Offline

    Rockstar04

    Minecraft cant, but A LOT of plugins run in separate threads now, which means they can use multiple cores.
     
  7. Offline

    PunJedi

    Its a simple enough process. We run 8 cores, the inherent core 'use' itself will use as many cores as possible.

    Example. During a bad bukkit dev build we came up once with only 30 and hit 800% , using all 8 Cores.

    As it is right now, we are using about 104 to 110% with 147 members. Ill post the cpu specs in just a moment....
     
  8. Offline

    momai

    Sorry for my English guys. My server is 1.8.1 bukkit build 1143. After upgrading from 1.7 to 1.8 overall CPU load increased a lot. It increases depending on how many players are online and sizes of opened map. For example, when I have 10 players online, CPU load is 70-90% all the time. Processor is Intel Core 2 Duo E7300. The question itself is pretty simple: is this high CPU load caused by a bukkit build or will it be the same on the final build? I don't really want to buy new hardware and stuff
     
  9. Offline

    Zothen

    How do you review the CPU load? Can you see what the mc-server process uses up to differ it from other stuff that the computer runs? Also, is it a dedicated server?
     
  10. Offline

    momai

    This was overall CPU load. MC process itself loads the CPU by 65-75%. The old 1.7.3 version with a number of plugins was loading CPU only by 20-30%

    Yes, dedicated server. Windows server 2003
     
  11. Offline

    strontkever

    my i7 2600k with 8gb ram and 16 players only uses 1-5%

    [edit] atm with 1.8 its even using less then with 1.7 (3-15% back then)

    not really helping anyone saying this but i like it :)

    plugins i use atm:

    antirain
    bananatracks
    bpermissions
    essentials
    essentials protect
    essentials spawn
    herochat
    iconomy
    logblock
    logblockquestioner
    lwc
    mcdocs(werkt niet goed)
    minequery
    multiworld
    simplereserve(werkt nog niet)
    worldborder
    worldedit
    worldguard
     
  12. Offline

    momai

    On another PC also checked
    made:
    reinstall map
    Disabling the plug-ins
    Creating a completely new server, not on the bukkit
    Update java


    Intel Core 2 Duo E7300 win 2003 server
     
  13. Offline

    theresajayne

    I run a quiet Server (max 20 users usually 0)

    Since updating i have to not run the server as even with 0 users I get 100% cpu running on SuSE community server
    and running with this command line
    nohup java -Xmx1024M -Xms1024M -jar minecraft_server.jar nogui >/dev/null &

    top shows
    PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
    24533 root 20 0 1348m 298m 9296 S 100 15.0 0:54.33 java



    So what is going on, - Still waiting for the bukkit server update to update my 2 runecraft servers.
     
  14. Offline

    Nathan C

    Yep, 100% CPU usage here on a Sandy Bridge server with 20 something players.
     
  15. Offline

    Simanova

    Same cpu load as 1.7.3, using cb 1152, AMD Phenom II X2 @3,2Ghz per core
    List of used plugins

    100% = 1 core
    200% = 2 core

    0 player -> 2%
    1 player -> 12%
    2 player -> 18%
    3 player -> 24%
    4 player -> 30%
    5 player -> 36%

    Can run up to 15 players without cpu bottleneck. ( remember its an AMD cpu )

    [​IMG]
     
  16. Offline

    dlmarti

    Wow, that is so different from what I see. I see 1.8 generating 50% to 100% more cpu load. You sure about these numbers?

    How is this possible? I have never seen bukkit use more than 2 cores?

    EDIT by Moderator: merged posts, please use the edit button instead of double posting.
     
    Last edited by a moderator: May 19, 2016
  17. Offline

    Simanova

    Our plugins changed a little bit, because some are not compatible with 1.8 - should affect 1 or 2 percent but not more.
    Iam really sure about this numbers. The CPU doesnt clock down or up. ( Cool & Quiet deactivated )

    Its possible - bukkit can use 2+ threads for chunk compression since 1041 ...

    Code:
    +    private static final ChunkCompressionThread instance = new ChunkCompressionThread();
    EDIT by Moderator: merged posts, please use the edit button instead of double posting.
     
    Last edited by a moderator: May 19, 2016
  18. Offline

    Oneduality

    I'm running 1.8.1 on bukkit 1047 .. I noticed significant lag when I first launched as chunks were generated, but after that things leveled out to normal .. I only play 2-3 players at a time and the server I run on is fairly old .. it's a 2.4ghz intel, single core ( only hyperthreading ) and 1ghz of ram .. it has never been blazing fast, but it seems to handle 1.8.1 as well as it did 1.5 through 1.7 ..

    I'll probably move the server off my linux box and onto my windows 7 machine which is a 2.67ghz quad core machine with 4gb of ram

    I have a general question about 1.8.1 .. My world has been around since 1.5 and there's been a lot of it explored and built upon, I know there's new biome generation .. does that affect my existing land? or just new unexplored land? .. and if it does affect the existing land, can I expect to see any ruins anywhere?

    Oh and to add .. I run quite a few plugins, the only two that failed with the jump to 1.8 was dynmap which I just simply deleted and MyHome which I upgraded to solve .. now all of my plugins seem to be functioning ..

    My list of .jar files:

    ArrowWall.jar
    AutoSave.jar
    Backup.jar
    clear.jar
    FireControl.jar
    FoundDiamonds.jar
    godPowers.jar
    HeavenActivity.jar
    HeroicDeath.jar
    Housedeeds.0.7c.jar
    iConomy.jar
    Jail.jar
    kFriendFinder.jar
    LazyRoad.jar
    MagicCarpet.jar
    Minestairs.1.0.jar
    MoveCraft.jar
    mxImgImport.jar
    MyHome.jar
    Paid2Mine.jar
    PermissionsEx.jar
    Permissions.jar
    PlugMan.jar
    PortalStick.jar
    PorteCoulissante.jar
    RealTeleporter.jar
    Residence.jar
    RetractableBridge.jar
    SecretDoors.jar
    SimpleGive.jar
    SimpleWarp-1.1.0.jar
    SpawnMob.jar
    Superpickaxe.jar
    TimeShift.jar
    VanishNoPickup.jar
    WeatherControl.jar
    WhichMob.jar
    WorldEdit.jar
    WormholeXTremeWorlds-0.4.jar

    EDIT by Moderator: merged posts, please use the edit button instead of double posting.
     
    Last edited by a moderator: May 19, 2016
  19. Offline

    Simanova

    bukkit 1047 is not compatible with 1.8.1
     
  20. Offline

    momai

    I'm updated bukkit to 1150. After 5 attempts to start the server, the load dropped to 2-3% with no users.
     
  21. Offline

    Oneduality

    Sorry, it's a bit early for me ..
    version git-Bukkit-0.0.0-1047-gb7e47c5-b1153jnks (MC: 1.8.1)

    0.0.0-1047....etc .. build 1153 .. :) so I should have said 1153
     
  22. Offline

    PunJedi

    I will add that we have a Java tuner that is an outright master at what he does. So on our 10gig heap , Ramdrive we run cleanup and JVm monitoring. This allows us to very closely monitor lag.

    1. use //remove xp -1 this gets rid of dropped orbs (Yes, they can still lag)

    2. We run only the most stable plugins over Bukkit to ensure the best run.

    for example. General doesnt yet hook into the new iConomy6 so that was disconnected to prevent errors.

    We noticed a few plugins that although wouldn't give an error (no debug for 1.8 maybe?), would still be pulling down serious load on the server.

    Its a touch of constant monitoring, constant informing members to adjust client settings, and constantly updating to the latest Bukkit devs and watching the numbers....

    Ah yes, and I had stated I would post our specs....

    Ram​

    24 GB

    Network​

    1Gbps
    Processor​

    2.4GHz E5620

    OS​

    Centos 5.5 x64 Base

    Running on SaS Drive 300G
     
  23. Offline

    strontkever

    my question is: are there any people not having this problem at all, like me?
     
  24. Offline

    Oneduality

    I'm not having it .. I had initial lag until everything loaded .. after a couple of minutes it was running normally, and my machine is very under-powered.. seems to be running fine for me
     
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