[SOLVED]Extremely Slow Site

[GabDT]

Hi everyone, we have a slow problem with our site. By doing various tests of the TTFB we noticed that the wait time is minimum 3-4 seconds and rises up to 20 seconds, I usually solve by restarting apache / mysql but after a short time the situation returns as before.

We use Prestashop 1.6.1.22 with Warehouse theme on a dedicated server with 8 cores and 32GB of ram, and the catalog has about 5k products

The situation is quite serious since we lose a lot of sales a day, and we would like to try to resolve the situation as soon as possible. Does anyone have any idea where this extreme slowness can come from?
 

Edited June 19, 2020 by GabDT (see edit history)

[Prescol]

Probably some non well developed module is trying to request information from a slow server. You can check the time spent on each module by enabling PROFILING_MODE

[musicmaster]

In case you didn't understand Prescol's suggestion:

In config/defines.inc.php you should set '_PS_DEBUG_PROFILING_' to true.

The result will be that below your pages you will see a long list of all the mysql calls being made and how long they took. Look for the one that took the longest.

[GabDT]

The problem was due to some badly set cron jobs, which kept the server busy more than necessary. Now I have modified them and the site seems to be going well, thanks a lot for the help