My minecraft server Crashed

i get This error i dont know how to fix it nor do i know whats wrong so can someone please help ?







---- Minecraft Crash Report ----
// There are four lights!

Time: 3/26/14 8:40 PM
Description: Exception in server tick loop

java.lang.OutOfMemoryError: GC overhead limit exceeded


A detailed walkthrough of the error, its code path and all known details is as follows:
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-- System Details --
Details:
Minecraft Version: 1.7.2
Operating System: Linux (amd64) version 2.6.18-348.16.1.el5
Java Version: 1.7.0_01, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 59656776 bytes (56 MB) / 477233152 bytes (455 MB) up to 477233152 bytes (455 MB)
JVM Flags: 3 total; -XX:MaxPermSize=192m -Xms512M -Xmx512M
AABB Pool Size: 9152 (512512 bytes; 0 MB) allocated, 9152 (512512 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
CraftBukkit Information:
Running: CraftBukkit version git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks (MC: 1.7.2) (Implementing API version 1.7.2-R0.4-SNAPSHOT) true
Plugins: { WorldBorder v1.7.8 com.wimbli.WorldBorder.WorldBorder [Brettflan], GroupManager v2.0 (2.9.2) (Phoenix) org.anjocaido.groupmanager.GroupManager [AnjoCaido, Gabriel Couto, ElgarL], NoCheatPlus v3.10.9-RC-sMD5NET-b673 fr.neatmonster.nocheatplus.NoCheatPlus [NeatMonster, asofold, Evenprime], WorldEdit v5.6 com.sk89q.worldedit.bukkit.WorldEditPlugin [], ABroadcast v1.0.5.5 com.webs.mcsoftworks.plugins.abroadcastrld.ABroadcastRLD [], FrameProtect v2.5 ch.dragon252525.frameProtect.FrameProtect [Dragon252525], MOTD v3.2 me.oliver276.server.Main [], Buycraft v6.6 net.buycraft.Plugin [Tebex Technologies Ltd], mcore v7.0.2 com.massivecraft.mcore.MCore [Cayorion], Vault v1.2.31-b411 net.milkbowl.vault.Vault [cereal, Sleaker, mung3r], Multiverse-Core v2.4-b527 com.onarandombox.MultiverseCore.MultiverseCore [Rigby, fernferret, lithium3141, main--], PermissionsEx v1.20.4 ru.tehkode.permissions.bukkit.PermissionsEx [[t3hk0d3, zml]], KitsPreview v1.0.3 com.gmail.louisyuhei123.kitspreview.KitsPreview [], AbsoluteWelcome v1.0 me.absolute.welcome.Welcome [absolute], Votifier v1.9 com.vexsoftware.votifier.Votifier [blakeman8192, Kramer], WorldGuard v5.9 com.sk89q.worldguard.bukkit.WorldGuardPlugin [], Essentials v2.12.2 com.earth2me.essentials.Essentials [Zenexer, ementalo, Aelux, Brettflan, KimKandor, snowleo, ceulemans, Xeology, KHobbits, md_5, Iaccidentally], EssentialsProtect v2.12.2 com.earth2me.essentials.protect.EssentialsProtect [Zenexer, ementalo, Aelux, Brettflan, KimKandor, snowleo, ceulemans, Xeology, KHobbits], Enjin_Minecraft_Plugin v2.5.3 com.enjin.officialplugin.EnjinMinecraftPlugin [www.Enjin.com], EssentialsSpawn v2.12.2 com.earth2me.essentials.spawn.EssentialsSpawn [Zenexer, ementalo, Aelux, Brettflan, KimKandor, snowleo, ceulemans, Xeology, KHobbits], Multiverse-Portals v2.4-b548 com.onarandombox.MultiversePortals.MultiversePortals [Rigby, fernferret], EssentialsChat v2.12.2 com.earth2me.essentials.chat.EssentialsChat [Zenexer, ementalo, Aelux, Brettflan, KimKandor, snowleo, ceulemans, Xeology, KHobbits, md_5, Okamosy, Iaccidentally], Factions v2.3.0 com.massivecraft.factions.Factions [Cayorion, Brettflan],}
Warnings: DEFAULT
Threads: { WAITING pool-38-thread-1: [sun.misc.Unsafe.park(Native Method), java.util.concurrent.locks.LockSupport.park(Unknown Source), java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source), java.util.concurrent.LinkedBlockingQueue.take(Unknown Source), java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source), java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source), java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source), java.lang.Thread.run(Unknown Source)], TIMED_WAITING Timer-5: [java.lang.Object.wait(Native Method), java.util.TimerThread.mainLoop(Unknown Source), java.util.TimerThread.run(Unknown Source)], TIMED_WAITING Timer-0: [java.lang.Object.wait(Native Method), java.util.TimerThread.mainLoop(Unknown Source), java.util.TimerThread.run(Unknown Source)], RUNNABLE Netty IO #3:
Failed to handle CraftCrashReport:
java.lang.OutOfMemoryError: GC overhead limit exceeded

Profiler Position: N/A (disabled)
Vec3 Pool Size: ~~ERROR~~ NullPointerException: null
Player Count: 4 / 100; [EntityPlayer['King_Dahdah'/2508107, l='SecretPvP', x=5275.16, y=6.00, z=4625.30](King_Dahdah at 5275.158903919087,6.0,4625.300000011921), EntityPlayer['ItsShivers'/2503983, l='SecretPvP', x=5846.70, y=46.00, z=4674.85](ItsShivers at 5846.6983331572565,46.0,4674.853744274682), EntityPlayer['mrBeastKing1'/2504255, l='SecretPvP_nether', x=707.93, y=39.00, z=576.53](mrBeastKing1 at 707.9279926089703,39.0,576.526828566705), EntityPlayer['heifer717'/2505345, l='SecretPvP_nether', x=719.61, y=40.00, z=581.57](heifer717 at 719.6148071951591,40.0,581.5722332210498)]
Is Modded: Definitely; Server brand changed to 'CraftBukkit'
Type: Dedicated Server (map_server.txt)