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[apache] / docs / manual / mod / mod_usertrack.xml

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<!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
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<modulesynopsis metafile="mod_usertrack.xml.meta">
<name>mod_usertrack</name>
<description>
<em>Clickstream</em> logging of user activity on a site
</description>
<status>Extension</status>
<sourcefile>mod_usertrack.c</sourcefile>
<identifier>usertrack_module</identifier>

<summary>
    <p>Previous releases of Apache have included a module which
    generates a 'clickstream' log of user activity on a site using
    cookies. This was called the "cookies" module, mod_cookies. In
    Apache 1.2 and later this module has been renamed the "user
    tracking" module, mod_usertrack. This module has been
    simplified and new directives added.</p>
</summary>


<section id="logging">
<title>Logging</title>

    <p>Previously, the cookies module (now the user tracking
    module) did its own logging, using the <directive>CookieLog</directive>
    directive. In this release, this module does no logging at all.
    Instead, a configurable log format file should be used to log
    user click-streams. This is possible because the logging module
    now allows multiple log files. The cookie itself is logged by
    using the text <code>%{cookie}n</code> in the log file format. For
    example:</p>
<example>
CustomLog logs/clickstream "%{cookie}n %r %t"
</example>

    <p>For backward compatibility the configurable log module
    implements the old <directive
    module="mod_log_config">CookieLog</directive> directive, but this
    should be upgraded to the above <directive
    module="mod_log_config">CustomLog</directive> directive. </p>
</section>

<section id="cookiedate">
<title>2-digit or 4-digit dates for cookies?</title>

    <p>(the following is from message
    &lt;022701bda43d$9d32bbb0$1201a8c0@christian.office.sane.com&gt;
    in the new-httpd archives) </p>
<pre>
From: "Christian Allen" &lt;christian@sane.com&gt;
Subject: Re: Apache Y2K bug in mod_usertrack.c
Date: Tue, 30 Jun 1998 11:41:56 -0400

Did some work with cookies and dug up some info that might be useful.

True, Netscape claims that the correct format NOW is four digit dates, and
four digit dates do in fact work... for Netscape 4.x (Communicator), that
is.  However, 3.x and below do NOT accept them.  It seems that Netscape
originally had a 2-digit standard, and then with all of the Y2K hype and
probably a few complaints, changed to a four digit date for Communicator.
Fortunately, 4.x also understands the 2-digit format, and so the best way to
ensure that your expiration date is legible to the client's browser is to
use 2-digit dates.

However, this does not limit expiration dates to the year 2000; if you use
an expiration year of "13", for example, it is interpreted as 2013, NOT
1913!  In fact, you can use an expiration year of up to "37", and it will be
understood as "2037" by both MSIE and Netscape versions 3.x and up (not sure
about versions previous to those).  Not sure why Netscape used that
particular year as its cut-off point, but my guess is that it was in respect
to UNIX's 2038 problem.  Netscape/MSIE 4.x seem to be able to understand
2-digit years beyond that, at least until "50" for sure (I think they
understand up until about "70", but not for sure).

Summary:  Mozilla 3.x and up understands two digit dates up until "37"
(2037).  Mozilla 4.x understands up until at least "50" (2050) in 2-digit
form, but also understands 4-digit years, which can probably reach up until
9999.  Your best bet for sending a long-life cookie is to send it for some
time late in the year "37".
</pre>

</section>

<directivesynopsis>
<name>CookieDomain</name>
<description>The domain to which the tracking cookie applies</description>
<syntax>CookieDomain <em>domain</em></syntax>
<contextlist>
<context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<override>FileInfo</override>

<usage>

    <p>This directive controls the setting of the domain to which
    the tracking cookie applies. If not present, no domain is
    included in the cookie header field.</p>

    <p>The domain string <strong>must</strong> begin with a dot, and
    <strong>must</strong> include at least one embedded dot. That is,
    <code>.foo.com</code> is legal, but <code>foo.bar.com</code> and 
    <code>.com</code> are not.</p>

    <note>Most browsers in use today will not allow cookies to be set
    for a two-part top level domain, such as <code>.co.uk</code>, 
    although such a domain ostensibly fulfills the requirements
    above.<br /> 
    
    These domains are equivalent to top level domains such as
    <code>.com</code>, and allowing such cookies may be a security
    risk. Thus, if you are under a two-part top level domain, you
    should still use your actual domain, as you would with any other top
    level domain (for example <code>.foo.co.uk</code>).
    </note> 
            
</usage>
</directivesynopsis>


<directivesynopsis>
<name>CookieExpires</name>
<description>Expiry time for the tracking cookie</description>
<syntax>CookieExpires <em>expiry-period</em></syntax>
<contextlist>
<context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<override>FileInfo</override>

<usage>
    <p>When used, this directive sets an expiry time on the cookie
    generated by the usertrack module. The <em>expiry-period</em>
    can be given either as a number of seconds, or in the format
    such as "2 weeks 3 days 7 hours". Valid denominations are:
    years, months, weeks, days, hours, minutes and seconds. If the expiry
    time is in any format other than one number indicating the
    number of seconds, it must be enclosed by double quotes.</p>

    <p>If this directive is not used, cookies last only for the
    current browser session.</p>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>CookieName</name>
<description>Name of the tracking cookie</description>
<syntax>CookieName <em>token</em></syntax>
<default>CookieName Apache</default>
<contextlist>
<context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<override>FileInfo</override>

<usage>
    <p>This directive allows you to change the name of the cookie
    this module uses for its tracking purposes. By default the
    cookie is named "<code>Apache</code>".</p>

    <p>You must specify a valid cookie name; results are
    unpredictable if you use a name containing unusual characters.
    Valid characters include A-Z, a-z, 0-9, "_", and "-".</p>
</usage>
</directivesynopsis>

<directivesynopsis>
<name>CookieStyle</name>
<description>Format of the cookie header field</description>
<syntax>CookieStyle
    <em>Netscape|Cookie|Cookie2|RFC2109|RFC2965</em></syntax>
<default>CookieStyle Netscape</default>
<contextlist>
<context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<override>FileInfo</override>

<usage>
    <p>This directive controls the format of the cookie header
    field. The three formats allowed are:</p>

    <ul>
      <li><strong>Netscape</strong>, which is the original but now deprecated
      syntax. This is the default, and the syntax Apache has
      historically used.</li>

      <li><strong>Cookie</strong> or <strong>RFC2109</strong>, which is the syntax that
      superseded the Netscape syntax.</li>

      <li><strong>Cookie2</strong> or <strong>RFC2965</strong>, which is the most
      current cookie syntax.</li>
    </ul>

    <p>Not all clients can understand all of these formats. but you
    should use the newest one that is generally acceptable to your
    users' browsers. At the time of writing, most browsers only fully
    support <code>CookieStyle Netscape</code>.</p>
</usage>
</directivesynopsis>



<directivesynopsis>
<name>CookieTracking</name>
<description>Enables tracking cookie</description>
<syntax>CookieTracking on|off</syntax>
<default>CookieTracking off</default>
<contextlist>
<context>server config</context>
<context>virtual host</context>
<context>directory</context>
<context>.htaccess</context>
</contextlist>
<override>FileInfo</override>

<usage>
    <p>When <module>mod_usertrack</module> is loaded, and
    <code>CookieTracking on</code> is set, Apache will send a
    user-tracking cookie for all new requests. This directive can
    be used to turn this behavior on or off on a per-server or
    per-directory basis. By default, enabling
    <module>mod_usertrack</module> will <strong>not</strong> 
    activate cookies. </p>

</usage>
</directivesynopsis>

</modulesynopsis>