This tool is basically a BASH wrapper script around the "links" command that pulls info from the Apache default mod_status functionality and displays the results on the command line, similar to the "top" command.
- Apache with mod_status module enabled and functioning, ExtendedStatus directive in httpd.conf active
- links program installed
- netstat program installed
- Apache status page available at http://localhost/server-status
Run the script on the command line:
./atop
You can also pass the script a number to limit the lines of results returned (good for viewing on small screens). The default is 300 lines.
./atop 50
This would limit the results to 50 lines.
See here for a blog post on using atop: http://mossiso.com/2014/04/02/atop-apache-top-for-keeping-tabs-on-the-web-servers.html
a = sort all threads by time
c = sort by CPU, no GCRK_
i = list IPs connected to port 80 (uses Apache Server Status)
k = sort by K (Keep alives)
l = list IPs connected to all ports (uses netstat)
n = list IPs connected to port 80 (uses netstat)
o = sort open connections by CPU
p = sort only POST threads by time
r = raw apache status output (good with limit of at least 50)
s = search for a term, returns raw Apache Server Status results
w = sort by inactive workers
q = quit
Two other great options exist, written in python or perl.