Question Lag help

How to i fix this lag???
[19:24:39 WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 2232ms behind, skipping 44 tick(s)

I run the mac mini (late 2014). 8GB RAM. 1TB of memory and core i5

 

Enable performance timings in your bukkit configuration. Take a look at what is causing a large % drop in your TPS. Could be a poor performance plugin, or you may have too many players online or chunks/worlds loaded. Have you got all background apps closed if you're running a server on your laptop?

 

Thats not a unique message with a single cause - there are an infinite number of things that could have happened, which resulted in that.

You computer running too many things other than the server, and getting stuck on some other task... your network connection bogging down too long waiting to check for updates on some authors site before giving up, and during that time it put everything else on pause..
eventually your server says "I dont even want to try to play catchup with the queue of delayed things, just cut our losses and jump over them and start fresh before the clock gets out of synch too much.