An in-depth introduction to using Analog, a freeware traffic analyzer, to handle logs on public or internal servers. The article provides scripts, crontabs, and other goodies.

by Stew Benedict of CrossNodes, an EarthWeb site [May 24, 2001]

Analog is a free program by statistician Dr. Stephen Turner that will allow you to look at a number of statistics from your Web server in both numerical and graphical formats. Although targeted for public Web servers, it also works nicely to analyze access to internal servers. I'll be covering setting Analog up under Linux and Apache, but it can be used with a number of operating systems and Web servers.

Analog can be downloaded from www.statslab.cam.ac.uk/~sret1/analog/ and boasts the following features:

• Very fast: Dr Turner says he is uncompressing and processing 28 million logfile lines in 20 minutes on a 266MHz machine.
  
  
• Scalable: There are sites using it on logfiles of over 700 million lines, which is approximately a 70GB file.
  
  
• Highly configurable: By default, the output is very usable, and there are many options to produce up to 32 different reports.
  
  
• Generates reports in 35 languages.

As of this writing, the latest stable version is 4.16, and the beta is 4.90beta3.

Binaries are available for Windows, MacOS, BSD, Linux, HP-UX, Solaris, BeOS, OS/390, AS/400, and OpenVMS. Also, if you prefer, source code is available.

Web server support includes Apache, NCSA, Microsoft IIS, WebSite, Netscape, W3, and WebSTAR.

Dr. Turner also sponsors three mailing lists: analog-announce, analog-help, and analog-author. If you need additional help or just want to keep up with development, subscription information isavailable at www.statslab.cam.ac.uk/~sret1/analog/docs/mailing.html.

Installation
For the binary install, things will vary depending on your OS. There are full instructions for each on the Analog download page. If you are building from source, it's pretty painless in Unix:

	mkdir /usr/local/analog
	cp analog-4.16.tar.gz /usr/local/analog
	cd /usr/local/analog
	tar -xzf analog-4.16.tar.gz
	cd analog-4.16

	#define ANALOGDIR "/usr/local/analog/analog-4.16/

This is where Analog and its other files expect to be installed. You should build from this directory or change the #define appropriately.

	#define LOGFILE "/usr/local/apache/logs/access_log"

	make

	./analog

If you set the options up correctly, and have permission to access to the log file specified, this should give you a screen of HTML output, which when viewed with a browser, should look something like this sample on the author's page, which shows some of the graphing options, including bar and pie graphs (available in the beta), as well as text data.

Go to page 2: Configuring Analog >