Question

I’ve set up an AJAX page refresh with setInterval. From time to time, the server is so slow that a new request is initiated before the previous one has completed.

How can I prevent that?

Answer 1

Use a timeout value that is shorter than your refresh interval. When the request times out, it will call the error handler so you’ll need to differentiate between time out errors and other types of errors in the handler.

 $.ajax({    type: 'POST',    url: 'some.php',    data: 'name=John&location=Boston',    timeout: 5000, /* ms or 5s */    success: function(msg){      alert( 'Data Saved: ' + msg );    }  }); 

Docs at jquery.com. Example above from same source, but with added timeout value.