Yesterday I encountered a problem with the minecraft server version 1.7.2 and 1.7.4. When a specific user was logging in, the memory use of the minecraft service raised to 100% of the available memory and the server started swapping. This causes a very slow responding server and all the players where disconnected because of a timeout. Every time this users logs in this problem occurs. After some searching I found out it has something to do with the installed java version.
For a minecraft mini-game I wanted to give all the players a special item at predefined times. In this case: every ten minutes the game lasts, the players who are still remaining are getting a special item.
Off course I could be searching for a bukkit plugin, but we are playing the vanilla for this one. So I decided to write a bash script which is called from a cronjob.