So I am pretty new about nginx + php fpm. So I have few questions

1-) There is /etc/php5/fpm folder, and there is, php.ini (usual one), main.conf is for fpm's conf, and what is www.conf under pool.d file ?

2-) I set up slow php process log and there is error like this.

Jul 20 00:31:26.048298 [WARNING] [pool www] child 1322, script '/var/www/domain.com/public_html/wp-admin/index.php' executing too slow (25.107567 sec), logging
Jul 20 00:31:26.081453 [NOTICE] child 1322 stopped for tracing
Jul 20 00:31:26.081500 [NOTICE] about to trace 1322
Jul 20 00:31:26.112334 [ERROR] ptrace(PEEKDATA) failed: Input/output error (5)
Jul 20 00:31:26.134214 [NOTICE] finished trace of 1322
Jul 20 00:31:30.997358 [WARNING] [pool www] child 1322, script '/var/www/domain.com/public_html/wp-admin/index.php' execution timed out (30.056624 sec), terminating
Jul 20 00:31:31.009799 [WARNING] [pool www] child 1322 exited on signal 15 (SIGTERM) after 13459.318252 seconds from start
Jul 20 00:31:31.011699 [NOTICE] [pool www] child 12592 started
Exactly why
[pool www] child 1322 exited on signal 15 (SIGTERM) after 13459.318252 seconds from start
child 1322 rungs for 13459 secs. how come its possible and why ? My max php execute time is 10 seconds.

3-) Checking my top with Memory priority and it shows like


PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
4234 www-data 20 0 351m 106m 62m S 0 25.0 2:32.25 php5-fpm
12592 www-data 20 0 345m 103m 65m S 0 24.4 0:47.94 php5-fpm
8425 www-data 20 0 355m 102m 56m S 0 24.1 2:11.92 php5-fpm
1325 www-data 20 0 355m 98m 65m S 0 23.2 2:30.71 php5-fpm
1321 www-data 20 0 541m 81m 57m S 0 19.2 2:25.57 php5-fpm
12541 www-data 20 0 322m 80m 65m S 0 19.1 0:56.64 php5-fpm
1320 www-data 20 0 322m 80m 65m S 0 19.0 2:39.62 php5-fpm
1324 www-data 20 0 538m 79m 57m S 0 18.8 2:30.45 php5-fpm
10278 www-data 20 0 318m 73m 62m S 0 17.4 1:37.31 php5-fpm
4337 www-data 20 0 322m 73m 57m S 0 17.3 2:25.50 php5-fpm
7128 mysql 20 0 222m 8240 2028 S 0 1.9 0:24.19 mysqld
14552 root 20 0 39232 3684 1932 S 0 0.8 0:00.17 zsh
14539 root 20 0 70816 3472 2716 S 0 0.8 0:00.05 sshd
30469 www-data 20 0 74724 1304 592 S 0 0.3 0:03.01 nginx
14598 root 20 0 19352 1272 952 R 0 0.3 0:00.01 top
30473 www-data 20 0 74724 976 556 S 0 0.2 0:02.67 nginx
30468 www-data 20 0 74460 916 540 S 0 0.2 0:02.81 nginx
There is always 6-7 php5 fpm process runs and uses around %25 memory (isnt it too much) even tho there is no active connections on server. I traced those pids and its mostly like libmysql and other stuff not serving a website