Would you like to have a webserver that is constantly restarting? If you have a lot of visitors just up the value for max client connections (provided your server can handle the load). It could also be that the code running on your server is not very good at closing connections efficiently.
it happens not everyday, just like from 3 to 3 days, and it's always when I'm not at home...I just wanted to keep it as an automatic process. Server reaches maxclients then restarts.