Top & httpd - demystifying what is actually running

Question

I often use the "top" command to see what is taking up resources. Mostly it comes up with a long list of Apache httpd processes, which is not very useful. Is there any way to see a similar list, but such that I could see which PHP scripts etc. those httpd processes are actually running?

Answer 1

The php scripts happen so fast, top wouldn't show you very much. Or it would zip by quite quickly. Most webrequests are quite quick.

I think your best bet would be to have some type of real time log processor, that kept an eye on your access logs and updates stats for you of average run time, memory usage and stuff like that.

Answer 2

If you're concerned about long running processes (i.e. requests that take more than a second or two to execute), you'll be able to get an idea of them using Apache's mod_status. See the documentation, and an example of the output (from www.apache.org). This isn't unique to PHP, but applies to anything running inside an apache process.

Note that the www.apache.org status output is publicly available presumably for demonstration purposes -- you'd want to restrict access to yours so that not everyone can see it.

Answer 3

You could make your PHP pages time themselves and write their path and execution time to file or database. Note that would slow everything down while you were monitoring, but it would serve as a good measuring method.

It wouldn't be that interactive though. You'd be able to get daily or weekly results from it, but it'd be hard to see something meaningful within minutes or hours.

Answer 4

There's a top-like ncurses-based utility called apachetop which provides realtime log analysis for Apache. Unfortunately, the project has been abandoned and the code suffers from some bugs, however it's actually very much usable. Just don't run it as root, run it as any user with access to the web server log files and you should be fine.