Some of you already know that I like optimizing things (modules, applications), regarding speed and scalability. For optimizing, you typically benchmark and profile. Regarding web applications, what I find very helpful also is observing request duration over time.
I've been doing this for quite a while now, and I found out, that this is not very common, so I would like to give an example and explain why it can be helpful. I'm also interested in other examples and typical values. (The only post about something like this I found was http://blogs.perl.org/users/mo/2011/07/exciting-updates-to-metacpan.html)