"Can't keep up!" Spamming causes TONS of lag.

Okay - I am running a bukkit server with the following plugins:
www.the-other-side.info/plugins.html
All running the latest version/953.

The problem is this:
[WARNING] Can't keep up! Did the system time change, or is the server overloaded?

No matter if the server is running idle or the ftp server I have hosted on it is being used, etc..., the server will spam this message once every few seconds for up to 20 minutes. During this time, there is EXTREME server lag. The only way to fix it on the spot is to:
a) Restart the server
b) Wait it out.

Here are some examples:
(When these occurred, you would be able to place a block, destroy one, chat, use commands, etc... with a lag of up to a minute.)

Code:

2011-07-12 17:54:59 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:55:01 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:55:02 [INFO] §f[§dUnicorn§f] §7summerlilly12§f: §fi built a dirt floor to work on the ceiling
2011-07-12 17:55:22 [INFO] §f[§aMod§f] §7sburlington6§f: §fthis is cool
2011-07-12 17:55:25 [INFO] §9[PLAYER_COMMAND] mrlongname: /home
2011-07-12 17:55:28 [INFO] §f[§aMod§f] §7sburlington6§f: §fi like the wool stuff
2011-07-12 17:55:38 [INFO] §f[§dUnicorn§f] §7summerlilly12§f: §fyeah its all gunna be wool
2011-07-12 17:55:44 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:55:46 [INFO] §f[§dUnicorn§f] §7summerlilly12§f: §f:)
2011-07-12 17:55:49 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:55:55 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:55:58 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:56:03 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:56:06 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:56:10 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:56:14 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:56:24 [INFO] §9[PLAYER_COMMAND] summerlilly12: /pay sburlington6 740
2011-07-12 17:56:26 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-12 17:56:34 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?

Code:

2011-07-15 15:33:24 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:38:44 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:38:52 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:39:23 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:39:26 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:39:31 [INFO] §f[§cAdmin§f] §7mastajack7§f: §flaggy
2011-07-15 15:39:33 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:39:44 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:39:55 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:39:56 [INFO] mastajack7 lost connection: disconnect.endOfStream
2011-07-15 15:40:29 [INFO] mastajack7 [/<IP>] lost connection
2011-07-15 15:40:39 [INFO] mastajack7 [/<IP>] logged in with entity id 69363 at ([theotherside] -326.6850395286048, 55.0, 67.50821719477779)
2011-07-15 15:40:44 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:41:00 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:42:42 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:42:45 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:43:29 [INFO] §9[PLAYER_COMMAND] mastajack7: /time day
2011-07-15 15:43:29 [WARNING] mastajack7 was denied access to command.
2011-07-15 15:43:36 [INFO] §9[PLAYER_COMMAND] mastajack7: /help
2011-07-15 15:43:36 [WARNING] mastajack7 was denied access to command.
2011-07-15 15:43:39 [INFO] §9[PLAYER_COMMAND] mastajack7: /home
2011-07-15 15:43:44 [INFO] [BBROTHER] Removed 0 old records because of age in 0h00m00s.
2011-07-15 15:43:46 [INFO] §9[PLAYER_COMMAND] mastajack7: /warp secret
2011-07-15 15:43:50 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:45:52 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:46:00 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:46:08 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:46:24 [INFO] §9[PLAYER_COMMAND] mastajack7: /home
2011-07-15 15:46:38 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:46:41 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:47:43 [INFO] §9[PLAYER_COMMAND] mastajack7: /warp shop
2011-07-15 15:48:02 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:48:04 [INFO] mastajack7 lost connection: disconnect.endOfStream
2011-07-15 15:48:16 [INFO] mastajack7 [/<IP>] logged in with entity id 72372 at ([theotherside] 61.5, 6.0, -51.5)
2011-07-15 15:48:33 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:48:57 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:49:11 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 15:49:15 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?

Code:

2011-07-15 10:19:49 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:26:12 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:26:41 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:27:12 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:27:40 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:33:51 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:33:58 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:34:23 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:34:27 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:34:43 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:35:05 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:35:34 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:35:47 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:35:51 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:35:55 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:35:57 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:04 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:06 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:11 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:14 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:21 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:40 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:42 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:36:52 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:37:10 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:37:18 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:37:41 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:38:09 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:38:38 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:39:08 [INFO] [BBROTHER] Removed 0 old records because of age in 0h00m01s.
2011-07-15 10:40:53 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:41:24 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:41:38 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 10:41:48 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 11:00:50 [INFO] [BBROTHER] Removed 0 old records because of age in 0h00m00s.
2011-07-15 11:22:29 [INFO] [BBROTHER] Removed 0 old records because of age in 0h00m00s.
2011-07-15 11:44:09 [INFO] [BBROTHER] Removed 0 old records because of age in 0h00m00s.
2011-07-15 11:57:45 [INFO] sburlington6 [/<IP>] logged in with entity id 5977 at ([theotherside] 351.7076389162205, 67.0, -262.9383326343493)
2011-07-15 11:57:47 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 11:58:25 [INFO] §9[PLAYER_COMMAND] sburlington6: /home
2011-07-15 11:58:29 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?
2011-07-15 12:01:22 [INFO] §9[PLAYER_COMMAND] sburlington6: /back
2011-07-15 12:01:26 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?

(There are many more)

The server is currently running with 3Gb of memory (The most we ever have on at one time is 5 or so, and it runs with 500Mb left avail then, also geting 2 more GB this coming Monday). Other programs running include:
RealVNC Server
U-Serv (3 ftp accounts)
Subsonic (100mb cache)

Any help is appreciated.

-Fisher

I don't think it matters, but I am running MySQL for LWC and BigBrother (set for 30 days).

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

 

What type of CPU does your server have? It's most likely that the CPU can't handle the load... (I'm not sure the correct wording for that, so hopefully you get it..)

The RAM doesn't really matter for that, it's the CPU. I have left 6 GB RAM on my server nearly all the time and I still get this message, it's just 'bukkit' lol. (But it never lags my server)

 

It's a clunker for the most part.

IT's a Pentium D 3GHz, however, I log the CPU usage, and te highest it's been is 80%, and that was for more then a few seconds.

However, I always though Java used more RAM then anything else. But there are no problems there. I'm assuming it's got something to do with a certain plugin. But there isn't really a way to test it (by disabling one and looking) because there can be hours between these lag spikes.

Does anyone know of a tool that can track the performance of each plugin?

 

LWC has been notorious (not sure if it still is) for causing lag. Try switching to something simpler, like Lockette, it seemed to help my server at least.
Also, maybe try a different logging plugin because Ive heard BigBrother causes lag spikes. We use Datalog, but LogBlock is just as good. MySQL has also seemed to increase speed, instead of flat file or SQLite/H2 storage. Try setting up at least your logging plugin with MySQL, that might help.

Lastly, do you have a large world? That error is caused because the PC cannot keep up with the server, often because there are too many requests for too many different chunks to be loaded at the same time. Try adding a border to your world with something like "BorderGuard" and look at "Performance Tweaks," though I'm not sure if it's updated.

Sorry I cannot link any plugins at this time, I am posting from my phone, but Ill be glad to any plugin links, that you cannot find, when I return home.