How to determine why the site is loading for a long time?

Question

System administration

Hello, is it possible to somehow determine the reason why the pages of the site are loading for a long time, the problem is in the database or in the php code.

Answer 1

1. The time the response was written should be recorded in the web server log
   
2. The database most likely has a separate slow query log or the ability to find out which queries are currently hanging
   
3. Accordingly, if not the database, then the problem is in the code
   

Answer 2

https://developers.google.com/speed/pagespeed/insi... - в помощь

Answer 3

Сайт может долго грузится не только из-за php или базы, может еще и сервер тормозить, например если диск переполнен, износился и т.п.