I modify access and error log formats by add %L parameter.
In my error log i get this:
[Tue Nov 03 02:55:33.635958 2015] [VjiEkn8AAAEAAHuBfzkAAABB] [-:error]
[pid 31617:tid [client IP:PORT] PHP Warning:
unlink(/tmp/file_name.txt): No such file or directory in
/var/www/file_test.php on line 1, referer REFERER
If i try to find this ID in access logs - nothing found.
If i search request by referer, pid, ip and port combination - there
is also no ID