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<title>Using Analog for Virtual Hosts (Separate Logfiles)</title>
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<h1 align="center">
HOW-TO<br>
Use <A HREF="http://www.analog.cx/">Analog</a> for Virtual Hosts<br>
(Using Separate Logfiles)</h1>

<P ALIGN="center">This HOW-TO written by
<A HREF="mailto:peter@cyberscreen.com">Peter Rose</a>.
<br>Converted to HTML and Step Three added by
<a href="mailto:analog-author@lists.meer.net">Stephen Turner</a>.
</p>
<p>
One of the great things about Analog is that it can easily be used to offer
different customised output to multiple virtual hosts on the same server.
<p>
This is an obvious asset if you host several domains on your server and want
to offer all your customers the benefit of daily/weekly/monthly Analog stats,
but not all of them require the same level of reporting or the same 'look'.
<p>
This real-world example is based on Apache 1.3.12 running on RedHat Linux 6.1,
but should be applicable to any Unix-like platform. Steps Two and Three, and
the general ideas, should be helpful on Windows NT and other operating
systems, but for the details you'll have to ask someone else :-)

<h2>Step One</h2>

Make the necessary entries in the Apache Virtual Host sections.
<p>
Here's an example from my httpd.conf:
<pre>
&lt;VirtualHost 212.87.82.24&gt;
ServerName www.ontiles.com
SSLDisable
DocumentRoot /home/httpd/html/tileshop
ServerAdmin webmaster@ontiles.com
CustomLog logs/ontiles-referer_log  referer
TransferLog logs/ontiles.com-access_log
&lt;/VirtualHost&gt;

&lt;VirtualHost 212.87.82.24&gt;
ServerName www.nuw-maas.co.uk
SSLDisable
DocumentRoot /home/httpd/html/nuwmaas
ServerAdmin webmaster@cyberscreen.com
TransferLog logs/nuw-maas-access_log
&lt;/VirtualHost&gt;
</pre>
<p>
Here you can see there are 2 virtual hosts with different logging requirements:
<p>
ontiles.com wants to get a referer report as well as the regular access
statistics, whereas nuw-maas.co.uk only needs the basic access stats.

<h2>Step Two</h2>

Create a separate analog.cfg file for each domain. It's your choice whether
you want each domain's config file to <em>replace</em> or to
<em>supplement</em> the global analog.cfg - see Step Four for details.
<p>
For ontiles.com, we have a
file called (with stunning originality) ontilesanalog.cfg.  The relevant parts
from this are as follows:
<pre>
LOGFILE /etc/httpd/logs/ontiles.com-access_log
LOGFORMAT REFERRER
LOGFILE /etc/httpd/logs/ontiles-referer_log
OUTFILE /home/httpd/html/cyberscreen/stats/ontiles_stats.html 
HOSTNAME "ONTILES.COM"
HOSTURL "http://www.ontiles.com/"
IMAGEDIR "http://www.cyberscreen.com/images/"
LOGO "ontileslogo.jpg"
STYLESHEET ontilesanalogstyle.css
</pre>
Note the order in which the <kbd>LOGFILE</kbd> and <kbd>LOGFORMAT</kbd>
commands appear - if the <kbd>LOGFORMAT REFERRER</kbd> is not before the
<kbd>LOGFILE</kbd>
/etc/httpd/logs/ontiles-referer_log, it won't work!  You can see also that
we're giving the reports for this domain their own logo at the top of the page
and are using a stylesheet that will match that of their website.  Not
essential, but you can't beat the finishing touches :-)
<p>
Now here's the same section for the analog.cfg file for the other virtual host
- which, yes, you've guessed it, is called nuw-maasanalog.cfg.
<pre>
LOGFILE /etc/httpd/logs/nuw-maas-access_log
OUTFILE /home/httpd/html/cyberscreen/stats/nuw-maas_stats.html 
HOSTNAME "WWW.NUW-MAAS.CO.UK"
HOSTURL "http://www.nuw-maas.co.uk/"
IMAGEDIR "http://www.cyberscreen.com/images/"
LOGO "nuw-maaslogo.jpg"
STYLESHEET nuw-maassanalogstyle.css
</pre>

So by this time, you get the idea. This domain don't need the referrer report,
but they would like their own groovy logo and stylesheet applied to the
output.  You can, of course, take the opportunity within each domain's
analog.cfg file to tweak the output appearance, request floors and so on
according to each host's requirements.

<h2>Step Three</h2>

We also want a report for our own use with a summary of the usage for all the
virtual hosts. So we need to analyse all the logfiles together. The problem is
that the filenames appear in the logfiles as just /index.html for example, but
we want to see http://www.ontiles.com/index.html, so that we know which files
belong to which virtual hosts. This is where the second argument to the
<kbd>LOGFILE</kbd> command comes in. This argument specifies a prefix to add
to the filenames in that logfile. You can see this in this configuration file,
which we'll call all.cfg:
<pre>
LOGFILE /etc/httpd/logs/ontiles.com-access_log http://www.ontiles.com
LOGFILE /etc/httpd/logs/nuw-maas-access_log    http://www.nuw-maas.co.uk
OUTFILE /home/httpd/html/cyberscreen/stats/overall_stats.html 
HOSTNAME "Cyberscreen"
IMAGEDIR "http://www.cyberscreen.com/images/"
SUBDIR http://*
</pre>
Notice the <kbd>SUBDIR</kbd> command at the end. This enables us to see the
amount of traffic for each virtual host in the Directory Report. This
information is not in the Virtual Host Report, because the virtual host name
is just part of the filename, not an item on its own.
<p>
When we run this report, analog will give us a &quot;possible double
counting&quot; warning. This just means that the dates for the logfiles
overlap, and it's nothing to worry about because all the logfiles are from
separate virtual hosts.

<h2>Step Four</h2>

Now we have to knock up a little shell script to tell Analog to make a report
on the stats for our different hosts at runtime. This works for me:
<pre>
#!/bin/sh

cd /etc/httpd/analog4.0
./analog -G +gontilesanalog.cfg
./analog -G +gnuwmaasanalog.cfg
./analog -G +gall.cfg
</pre>

Obviously, the first line reflects the location of my analog - yours may well
be somewhere else.  And of course, if you've put Analog in your
<kbd>$PATH</kbd>, you won't need the <kbd>./</kbd> at the beginning of each
line.  What we're doing here is 
simply running Analog twice using a different config file each time.  I won't
say you can do this ad infinitum, but I'm up to 20 virtual hosts and Analog
processes the whole lot in seconds.  The important switches are the -G , which
tells Analog not to use the default config file, and the +g in front of each
cfg filename, which tells Analog to use that particular config file. No, you
don't leave a space before the filename.
<p>
If you include the -G, the individual config files replace the global
analog.cfg. If you don't include -G, then each domain will get the global
analog.cfg plus its own analog.cfg.

<h2>Step Five</h2>

Save the above script as 'runanalog' (or whatever) and chmod it 755.  Now you
can use the cron daemon to execute analog on all your virtual hosts
automatically at whatever frequency you desire.  In the case of Linux, this is
a definite no-brainer as under /etc you will find the directories cron.daily,
cron.weekly or cron.monthly.  My users like to have their stats pages updated
on a daily basis, so I just copied 'runanalog' into cron.daily, but you could
equally run weekly or monthly. If you offer a different service to different
hosts, you could have one 'runanalog' or the daily stats junkies and another
version in cron.monthly with the hosts that can't handle too much information.
<p>
And that's it! You now have Analog reports automatically generated and
customised for all your virtual hosts.
<hr>
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