title: How to update a website without making it go down?
body: <p>I need the best practice for updating one or more files on my website without making it go down;</p>
  
  <p>example, if i update Model.php file, the upload will take few seconds, like one or two seconds before it replaces the file on the server, in the meantime, the website will show some error that model.php is not found, or not complete, even if i suppress the errors, the website will die eventually.</p>
  
  <p>what is the best practice for that?</p>