On debian parent process is running as root, workers as www-data. You can run strace in backgroud, get its PID, curl your webpage, kill strace and read your stats.

list of all virtual hosts which are defined in all apache configuration files

Nginx (and other webservers like Apache) can be awkward to trace. They run as root, then switch to another user once they're ready to serve web pages. They also have a "master" process and multiple worker processes. The given command finds the process IDs of all Nginx processes, joins them together with a comma, then traces all of them at once with "sudo strace." System trace output can be overwhelming, so we only capture "networking" output. TIP: to kill this complex strace, do "sudo killall strace". Compare with a similar command: http://www.commandlinefu.com/commands/view/11918/easily-strace-all-your-apache-processes Show Sample Output

remove the IP from proxy reverse server and parentesis from real IP obtained from X-forwarder_IP Show Sample Output

(echo "https://example.com/"; echo "https://example.com/"; echo "https://example.com/"; echo "https://example.com/") | parallel -k 'ab -n 10000 -c 15 {}'

Check if your HTTP server is vulnerable to a very effective variant of slow HTTP attack called R.U.D.Y (R-U-Dead-Yet?). This command tries to keep many connections to the target web server and hold them open as long as possible. Affected server will exhaust its maximum concurrent connection pool and deny additional connection attempts from legitimate clients. Use it with caution!