Server failure

Hello,
Lately, I've been experiencing this problem using CraftBukkit Beta 1.4.2-R0.2 And have come across some severe crashes. After my server starts up there are no errors in the console. After 10 - 30 minutes of start up, there is a 1 minute lag spike followed by a crash. The console sends out the following error:

11.11 00:27:02 [Multicraft] Skipped 10 lines due to rate limit (30/s)
11.11 00:26:57 [Server] INFO at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:428)
11.11 00:26:57 [Server] INFO at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:495)
11.11 00:26:57 [Server] INFO at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:215)
11.11 00:26:57 [Server] INFO at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:578)
11.11 00:26:57 [Server] INFO at net.minecraft.server.DedicatedServerConnection.b(SourceFile:29)
11.11 00:26:57 [Server] INFO at net.minecraft.server.DedicatedServerConnectionThread.a(DedicatedServerConnectionThread.java:44)
11.11 00:26:57 [Server] INFO at net.minecraft.server.NetLoginHandler.c(NetLoginHandler.java:51)
11.11 00:26:57 [Server] INFO at net.minecraft.server.NetworkManager.b(NetworkManager.java:282)
11.11 00:26:57 [Server] INFO at net.minecraft.server.Packet254GetInfo.handle(SourceFile:23)
11.11 00:26:57 [Server] INFO at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:178)
11.11 00:26:57 [Server] INFO at net.minecraft.server.NetworkManager.d(NetworkManager.java:300)
11.11 00:26:57 [Server] INFO at java.lang.Thread.start(Unknown Source)
11.11 00:26:57 [Server] INFO at java.lang.Thread.start0(Native Method)
11.11 00:26:57 [Server] INFO java.lang.OutOfMemoryError: unable to create new native thread
11.11 00:26:57 [Server] SEVERE Encountered an unexpected exception OutOfMemoryError
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:428)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:495)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:215)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:578)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.DedicatedServerConnection.b(SourceFile:29)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.DedicatedServerConnectionThread.a(DedicatedServerConnectionThread.java:44)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.NetLoginHandler.c(NetLoginHandler.java:51)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.NetworkManager.b(NetworkManager.java:282)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.Packet254GetInfo.handle(SourceFile:23)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:178)
11.11 00:26:57 [Server] SEVERE at net.minecraft.server.NetworkManager.d(NetworkManager.java:300)
11.11 00:26:57 [Server] SEVERE at java.lang.Thread.start(Unknown Source)
11.11 00:26:57 [Server] SEVERE at java.lang.Thread.start0(Native Method)
11.11 00:26:57 [Server] SEVERE java.lang.OutOfMemoryError: unable to create new native thread

Please tell me what's wrong here, do I need more RAM?

Server Specs:
8GB of RAM
Average TPS: 18/19
4 Worlds (Main World (919 Chunks), The End, Nether and a flatland world for Events.
CraftBukkit Beta 1.4.2-R0.2
25 Plugins:
AntiCheat,
AutoMessage,
BuyCraft,
ChestShop,
DuraBlox,
Essentials,
EssentialsChat,
EssentialsSpawn,
EssentialsGroupManager,
EssentialsGroupBridge,
Factions,
MobArena,
Multiverse-Core,
Multiverse-Portals,
PvPTimer,
Simple-Region-Market,
Vault,
Votifier,
WorldBorder,
WorldEdit,
WorldGuard,
iConomy,
SimplyVanish,
Starter-Kit,

I've tried upgrading my RAM yet that still doesn't fix it. I've also figured it's one of my plugins doing it. I just can't get my head around which one,

Thanks!

Still getting this error after upgrading more RAM to 10GB.

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

 

The only way to find out for sure is to test your server without one of them, one after the other.

 

I've wanted to do that, but the server only crashes 20 - 30 minutes after startup, I would have to be looking through 25 plugins, half an hour for each plugin, but I guess that's my only choice.

 

Narrow it down by removing 3 or 4 at a time.

 

Thanks for the tip! I'll let you know if I found the plugin.

I see, all the plugins are fine. Server is fine, everything is fine when I whitelist it and just stay AFK.
If I un-whitelist it and loads of players join, it crashes.

I'm pretty sure my world corrupted and none of the corruption tools fix the problem.

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