Hi. I am making a web-site , which is a social network. There is need of making overall notification block/bar on the website.
User should be notified when a) there is new message b) there is new friend request c) there is new photo rating ....
As application (php/mysql) should be made with future calculation of minimum 100-1500 users online, what is the best practise to make such notificaion display? Should I make checks with each time users refresh their browser, or Jquery script which will ping the special check.php script each 10-15-20min...??? What is most professional practise ? Who can help?