# Adjusting child processes for PHP-FPM (Nginx)

## Determine if the max_children limit has been reached.
- `sudo grep max_children /var/log/php?.?-fpm.log.1 /var/log/php?.?-fpm.log`

## Determine system RAM and average pool size memory.
- `free -h`
- All fpm processes: `ps -ylC php-fpm7.0 --sort:rss`
- Average memory: `ps --no-headers -o "rss,cmd" -C php-fpm7.0 | awk '{ sum+=$1 } END { printf ("%d%s\n", sum/NR/1024,"M") }'`
- All fpm processes memory: `ps -eo size,pid,user,command --sort -size | awk '{ hr=$1/1024 ; printf("%13.2f Mb ",hr) } { for ( x=4 ; x<=NF ; x++ ) { printf("%s ",$x) } print "" }' | grep php-fpm`

## Calculate (pm.max_children = Total RAM dedicated to the web server / Max child process size)

- System RAM: 2GB
- Average Pool size: 85Mb
- `pm.max_children = 1500MB / 85MB = 17`

## Configure
`sudo vim /etc/php/7.0/fpm/pool.d/www.conf`

```
pm.max_children = 17
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3
pm.max_request = 1000
```