How to find out why php-fpm: pool www is completely loading the processor?

Question

PHP

Good afternoon! I have a store on Opencart and after installing a module from respected developers, the site stops opening, it throws out a 504 error, increasing the server response time leads to a 500 error. The logs report that one, then the second process lacks max_execution_time. Increasing these parameters to huge values, I still fall out the limits. I enabled slow log in php-fpm, but nothing gets there because of what is needed. In general, it is clear that the matter is in the module and its code, but how to find the cause?

Answer 1

after installing the module from respected developers, the site stops opening

respected developers are those who support their developments. Accordingly, either you have something set up wrong (read the dock to the module), or write to the developers in the support.
There is another option to figure it out on your own (but judging by "But the module consists of a large number of files, how can I determine which one to go to and use die?" This is not your option), or turn to freelance, because for such symptoms, no one cares for you cannot be specific.

Answer 2

Turn on error display and use die(). Go into the plugin code, first add die() to the beginning, then lower, lower and lower. Until the error occurs again. Thus, you will clearly find the line in which, most likely, a loop occurs. You'll figure it out there.