Server Unresponise / Unconnectable (includes error messages)

My server is running Craftbukkit, and at some point it became unreachable. It did not actually appear offline, or at least the IRC plugin was still running and when I checked the player list there were still players "connected". But nobody could actually connect to it, it was giving us an error:

Code:

java.net.sockettimeoutexception: read timed out

I did a stop and restarted the server and it came up fine. These are the 2 error messages that were listed in the console:

Code:

2011-02-27 08:37:46 [SEVERE] Exception in thread "Listen thread"
2011-02-27 08:37:46 [SEVERE] java.lang.OutOfMemoryError: unable to create new native thread
2011-02-27 08:37:46 [SEVERE]    at java.lang.Thread.start0(Native Method)
2011-02-27 08:37:46 [SEVERE]    at java.lang.Thread.start(Unknown Source)
2011-02-27 08:37:46 [SEVERE]    at net.minecraft.server.NetworkManager.<init>(SourceFile:94)
2011-02-27 08:37:46 [SEVERE]    at net.minecraft.server.NetLoginHandler.<init>(NetLoginHandler.java:21)
2011-02-27 08:37:46 [SEVERE]    at net.minecraft.server.NetworkAcceptThread.run(SourceFile:49)

Code:

2011-02-27 09:00:04 [SEVERE] java.net.SocketException: Connection reset
2011-02-27 09:00:04 [SEVERE]    at java.net.SocketInputStream.read(Unknown Source)
2011-02-27 09:00:04 [SEVERE]    at java.net.SocketInputStream.read(Unknown Source)
2011-02-27 09:00:04 [SEVERE]    at java.io.FilterInputStream.read(Unknown Source)
2011-02-27 09:00:04 [SEVERE]    at net.minecraft.server.Packet.b(SourceFile:113)
2011-02-27 09:00:04 [SEVERE]    at net.minecraft.server.NetworkManager.f(SourceFile:155)
2011-02-27 09:00:04 [SEVERE]    at net.minecraft.server.NetworkManager.c(SourceFile:9)
2011-02-27 09:00:04 [SEVERE]    at net.minecraft.server.NetworkReaderThread.run(SourceFile:62)

And here is the Craftbukkit version:

Code:

2011-02-27 15:34:36 [INFO] This server is running Craftbukkit version git-Bukkit-0.0.0-450-gd3c1ba4-b432jnks (MC: 1.3)

--- merged: Feb 27, 2011 10:11 PM ---
And it just did it again, whee!

Code:

2011-02-27 17:09:01 [SEVERE] java.lang.OutOfMemoryError: unable to create new native thread
2011-02-27 17:09:01 [SEVERE]    at java.lang.Thread.start0(Native Method)
2011-02-27 17:09:01 [SEVERE]    at java.lang.Thread.start(Unknown Source)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:70)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.Packet1Login.a(SourceFile:46)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.NetworkManager.a(SourceFile:230)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:34)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.NetworkListenThread.a(SourceFile:87)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:338)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:253)
2011-02-27 17:09:01 [SEVERE]    at net.minecraft.server.ThreadServerApplication.run(SourceFile:366)
2011-02-27 17:09:01 [SEVERE] Unexpected exception
java.lang.OutOfMemoryError: unable to create new native thread
        at java.lang.Thread.start0(Native Method)
        at java.lang.Thread.start(Unknown Source)
        at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:70)
        at net.minecraft.server.Packet1Login.a(SourceFile:46)
        at net.minecraft.server.NetworkManager.a(SourceFile:230)
        at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:34)
        at net.minecraft.server.NetworkListenThread.a(SourceFile:87)
        at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:338)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:253)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:366)
2011-02-27 17:09:20 [SEVERE] Exception in thread "Listen thread"
2011-02-27 17:09:20 [SEVERE] java.lang.OutOfMemoryError: unable to create new native thread
2011-02-27 17:09:20 [SEVERE]    at java.lang.Thread.start0(Native Method)
2011-02-27 17:09:20 [SEVERE]    at java.lang.Thread.start(Unknown Source)
2011-02-27 17:09:20 [SEVERE]    at net.minecraft.server.NetworkManager.<init>(SourceFile:94)
2011-02-27 17:09:20 [SEVERE]    at net.minecraft.server.NetLoginHandler.<init>(NetLoginHandler.java:21)
2011-02-27 17:09:20 [SEVERE]    at net.minecraft.server.NetworkAcceptThread.run(SourceFile:49)
2011-02-27 17:10:06 [SEVERE] java.net.SocketException: Connection reset
2011-02-27 17:10:06 [SEVERE]    at java.net.SocketInputStream.read(Unknown Source)
2011-02-27 17:10:06 [SEVERE]    at java.net.SocketInputStream.read(Unknown Source)
2011-02-27 17:10:06 [SEVERE]    at java.io.FilterInputStream.read(Unknown Source)
2011-02-27 17:10:06 [SEVERE]    at net.minecraft.server.Packet.b(SourceFile:113)
2011-02-27 17:10:06 [SEVERE]    at net.minecraft.server.NetworkManager.f(SourceFile:155)
2011-02-27 17:10:06 [SEVERE]    at net.minecraft.server.NetworkManager.c(SourceFile:9)
2011-02-27 17:10:06 [SEVERE]    at net.minecraft.server.NetworkReaderThread.run(SourceFile:62)
2011-02-27 17:10:42 [SEVERE] java.net.SocketException: Connection reset
2011-02-27 17:10:42 [SEVERE]    at java.net.SocketInputStream.read(Unknown Source)
2011-02-27 17:10:42 [SEVERE]    at java.net.SocketInputStream.read(Unknown Source)
2011-02-27 17:10:42 [SEVERE]    at java.io.FilterInputStream.read(Unknown Source)
2011-02-27 17:10:42 [SEVERE]    at net.minecraft.server.Packet.b(SourceFile:113)
2011-02-27 17:10:42 [SEVERE]    at net.minecraft.server.NetworkManager.f(SourceFile:155)
2011-02-27 17:10:42 [SEVERE]    at net.minecraft.server.NetworkManager.c(SourceFile:9)
2011-02-27 17:10:42 [SEVERE]    at net.minecraft.server.NetworkReaderThread.run(SourceFile:62)