Apachetop on Amazon Linux

There's handy utility for monitoring Apache logs almost in real time called apachetop. Apachetop shows the traffic your Apache is handling based on the log entries Apache writes. Of course you can read the log files with some file viewer too, but apachetop gives you an overall picture of what's currently happening on your web site, which is not easy to achieve by reading only the log files.

Initially I had some trouble on installing apachetop on EC2 running Amazon Linux, but I managed to do it with these simple commands.

% wget http://www6.atomicorp.com/channels/atomic/centos/5/x86_64/RPMS/libadns-1.4-3.el5.art.x86_64.rpm
% wget http://pkgs.repoforge.org/apachetop/apachetop-0.12.6-3.el5.rf.x86_64.rpm
% yum install libadns-1.4-3.el5.art.x86_64.rpm
% yum install apachetop-0.12.6-3.el5.rf.x86_64.rpm

The commands above download the Centos RPM files and install them using yum. It's better to download the RPMs and install them manually than add some random Centos repositories to your system. Although Amazon is mostly compatible with Centos, it's risky business use standard Centos repositories.

After installing, you can start the apachetop to monitor your Apache. If you have several virtual hosts each writing to different log file, you can add all of them to a single apachetop session. Let's assume you have virtual hosts vhost1 and vhost2, which write logs vhost1_access_log and vhost2_access_log. To monitor both of these, use the following command.

apachetop -f vhost1_access_log -f vhost2_access_log -H 5000 -s 1 -l

I also added some extra parameters here. The -H sets how many total hits the monitoring shows before starting to rotate the log data. The -s sets how many URL path elements are used to distinguish different URLs. For example -s 2 would set mean that /path1/path2/path3 and /path1/path2/path4 would be counted as one URLs. On the other hand, /path1/path3/path2 and /path1/path2/path3 would be different. The last switch -l just says that all URLs should be changed to lowercase before comparing them to each other. Use man apachetop to see more details.