My server usually sits at a strong 20 TPS. However earlier today I had 84 players online and TPS started dropping. I'm not too sure what the cause is, so I ran a plugin profiler by using NoLagg's "examine" feature.

I was able to extract the plugin timings and noticed Precious Stones was the 2nd longest at 1457.0 ms.

Most of the events are <200 ms, however the PlayerRespawnEvent was at 970.0 ms. I'm not sure if this would affect server performance, but I figured I should inform you in case there's opportunities for optimizations. I have linked my .exam file if you wanted to take a look for yourself. I hope this bid of information helps!

https://dl.dropbox.com/u/12484037/2013_02_08-16_10_11.exam

Me too, I also noticed the same, if it helps here is my response time also examined with NoLagg:

http://pastebin.com/NkS3q3ty

I am using PS 9.5.5

Question for speculation... I have about 6 worlds on my server. If I list worlds that don't use PS in the "blacklisted-worlds" setting in my Config, will that significantly improve performance?

EDIT: Never mind, I just glanced at your source code. "blacklisted-worlds" isn't checked your handlePlayerSpawn()

Let me know if this helped

Pick up the latest build from Jenkins to test this out.

http://aikar.co/timings.php?url=1670892
last build

++ http://aikar.co/timings.php?url=1670915
but anyway when somebody join server tps goes down but aftre 2-3 min set normally

http://aikar.co/timings.php?url=1671021