My server : http://www.gametracker.com/server_info/206.217.142.139:25565/

Is on all day and always with people, but at intervals of more demand always shows 0/144 so that full

¿What happens?

Your server page is not showing any players online at the current time and at the same time is not reporting any players. You do appear to have a massive number of plugins running on your server. Once you review the list below, I would recommend removing them one at a time to see which is the culprit.

1. You are running the most recent version of the server
2. You are not running any extra query plugins like minecraftviewer