Server cpu drop on 0% when player join/leave

after sometime watching, cpu drop on 0% when player join/leave ?, same with plugins or without them.
it doesnt happen to every player, but to some player it happens and it's terrible lag.Any help ?

More informations, dude!
OS, specs, plugins, full startup log, the Permissionfile.

Then i'll try my best,
- frdmn

OS:centos 6.2
spec: amd opteron 3280, 16gb ram, software raid 1

like i said, it dosent have nothing with plugins, it happens with clean craftbukkit too.Whole minecraft server is on ramdisk, without ramdisk, this is terrible unplayable server, and it's dedicated server ....

Do you use any "*"-permissions nodes?

yes i do, few of them.

Don't do it! Never. Ever!

These nodes are responsible for major server lag while player joined / left cause of the huge amount of checks the Permission system has to do then.

Try not to use them and then to test again.

Good luck
- frdmn

ok thnx, today at night when there are little players, gona test and see if it works normal then