I am having around 20 to 30 page views/minute, around 30 users at the same time.
I am checking the nginx log but not sure how to analyse all those stuffs, I checked that script but seems to be deprecated? Analyzing Discourse Performance using NGINX logs
I also checked the Post-Install Maintenance section and did a apt-get install fail2ban, I am not sure if I have to do anything else but it seems to decrease slightly the load average.