I have had some issues with the default xdebug.profiler_output_name, as php-fpm is serving all requests from the same process ID, my tools dont seem to work very well (Webgrind and Clockwork).
I watched Dericks youtube video where he recomends using cachegrind.out.%R (See 1:15 at https://youtu.be/ttQgLBSpVvc?t=74)
Have other people had issues with this?