nginx

If you happen to develop large sites in Drupal, you might fall upon a case like this one, where different servers (namely at least one reverse proxy and one web server) interact, causing a series of chain reactions every time you change something. It might be frustrating, at times, to try and boost a coordinated system like this, and end up getting your users frustrated because part of it doen't work, when the rest (the part that *does* work) is super-fast.

This must appear in one opportunity in 1000, but it happened to me, so I bet it might have just happened to you... Munin is great, Nginx is great, and SSL is great, but when you mix all of them together, you might get some frustrating behaviour. If you don't know it already, you can test the results of a Munin plugin on Debian-based systems with the command

sudo munin-run [plugin]

For example, if your nginx_status graph in the Munin web interface is empty, you can try

sudo munin-run nginx_status

The name of the plugin will auto-complete with the TAB key, with any plugin

Just as a self reminder, this blog post explains why php-cgi might hang/stop silently when your load increases, and how to fix it, where it explains (in short) that fast-cgi should have the parameter PHP_FCGI_MAX_REQUESTS should equal 1000 or more (this can be done in /etc/default/php-fastcgi on my Ubuntu server).   Also worth a look is this page which has nothing to do with fast-cgi but describes how to increase th