Multi-player threading issue (Lag!)

So I've got a server running on a Linux Ubuntu 10.04 LTS host with 4 Nahalem cores and 8G of ram. With 6 users on the server, I'm getting significant lag. A little poking around gives me the following thread details on the server:

3283 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.02 java
3284 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.51 java
3285 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:19.82 java
3286 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:20.13 java
3287 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:19.87 java
3288 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:20.25 java
3289 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:06.00 java
3290 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.19 java
3291 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:02.83 java
3292 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.00 java
3293 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:21.13 java
3294 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:24.23 java
3295 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.00 java
3296 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:18.91 java
3297 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.00 java
3307 minecraf 20 0 4970m 4.4g 10m R 93.3 56.3 116:19.79 java
3308 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:02.40 java
3309 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:00.38 java
3310 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:25.70 java
3311 minecraf 20 0 4970m 4.4g 10m S 7.9 56.3 7:16.23 java
3322 minecraf 20 0 4970m 4.4g 10m S 6.9 56.3 12:14.76 java
3555 minecraf 20 0 4970m 4.4g 10m S 1.0 56.3 0:13.11 java
3556 minecraf 20 0 4970m 4.4g 10m S 2.0 56.3 0:38.07 java
3661 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:04.18 java
3662 minecraf 20 0 4970m 4.4g 10m S 2.0 56.3 0:20.88 java
3723 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:02.63 java
3724 minecraf 20 0 4970m 4.4g 10m S 3.9 56.3 0:10.69 java
3732 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:02.21 java
3733 minecraf 20 0 4970m 4.4g 10m S 1.0 56.3 0:07.52 java
3745 minecraf 20 0 4970m 4.4g 10m S 0.0 56.3 0:01.65 java
3746 minecraf 20 0 4970m 4.4g 10m S 2.9 56.3 0:06.52 java
3754 minecraf 20 0 4970m 4.4g 10m S 1.0 56.3 0:01.49 java
3755 minecraf 20 0 4970m 4.4g 10m S 2.0 56.3 0:05.83 java

One thread is eating up an entire core. My machine is only running at about 28% CPU, but the server is lagging pretty badly. I'm assuming this is a bug. Thoughts?

 

List your Craftbukkit version number, the plugins you are using and version numbers.
I have had terrible lag in the past with certain plugins. Without that info it becomes hard to determine the cause of the lag.

 

23:22:19 [INFO] This server is running Craftbukkit version git-Bukkit-1.0.1-R1-b1597jnks (MC: 1.0.1) (Implementing API version 1.0.1-R1)
23:22:20 [INFO] [SuperpermBridge] Superperm/Permissions bridge initialized
23:22:22 [INFO] PermissionsBukkit v1.2 is now enabled
23:22:22 [INFO] [SuperSpawn] enabled.
23:22:22 [INFO] [SuperpermBridge] Superperm/Permissions bridge enabled
23:22:22 [INFO] WorldBorder version 1.4.4 loading
23:22:22 [INFO] [MyWarp] MyWarp 2.0.1 enabled
23:22:22 [INFO] [MyHome] MyHome 2.1b enabled


That's it - it's pretty vanilla right now.

Bump. I know people are doing much larger servers than this - any input would be recommended.

And no, I'm not IO bound, and my map is too big for ramdisk.

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

 

did you try server without plugins ?
did you try plugins like NoLagg ? or ChunkManager ?