I. Common Commands & Tools

1. PHP Performance debugger

Strace is good tool to debug PHP performance. Firstly, you need to install it via

CentOS

yum install strace

Ubuntu

apt-get install strace

For detect all PHP-FPM we can use following command

 strace -c -f $(pgrep php-fpm | sed 's/\([0-9]*\)/\-p \1/g')

lstat + fstat + stat  is system call into file information

2. IP Monitor

netstat -ant | grep -v LISTEN | awk '{print $5}' | cut -d":" -f1 | sort | uniq -c | sort -rn

3. Disk application I/O monitor

iotop

4. Process monitor tools

htop

atop

top 

II. References