Apache HTTP Server Version 1.3

Module mod_usertrack

This module uses cookies to provide for a clickstream log of user activity on a site.

Status: Extension
Source File: mod_usertrack.c
Module Identifier: usertrack_module
Compatibility: Known as mod_cookies prior to Apache 1.3.

Summary

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.

Directives

• CookieDomain
• CookieExpires
• CookieFormat
• CookieName
• CookiePrefix
• CookieStyle
• CookieTracking

Logging

Previously, the cookies module (now the user tracking module) did its own logging, using the CookieLog 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 %{cookie}n in the log file format. For example:

CustomLog logs/clickstream "%{cookie}n %r %t"

2-digit or 4-digit dates for cookies?

From: "Christian Allen" <christian@sane.com>
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".

CookieDomain directive

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.

The domain string must begin with a dot, and must include at least one embedded dot. That is, ".foo.com" is legal, but "foo.bar.com" and ".com" are not.

CookieExpires directive

When used, this directive sets an expiry time on the cookie generated by the usertrack module. The expiry-period 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, 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.

If this directive is not used, cookies last only for the current browser session.

CookieFormat directive

When used, this directive determines whether the cookie used for user tracking is created using the default ("normal") format (eg: decimal values for items like the PID) or using a more compact format (eg: hexidecimal values).

CookieName directive

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

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 "-".

CookiePrefix directive

When used, this directive allows for the "string" to be prepended to the user tracking cookie. Care must be taken not to prepend a string that would result in a bogus cookie.

CookieStyle directive

This directive controls the format of the cookie header field. The three formats allowed are:

• Netscape, which is the original but now deprecated syntax. This is the default, and the syntax Apache has historically used.
• Cookie or RFC2109, which is the syntax that superseded the Netscape syntax.
• Cookie2 or RFC2965, which is the most current cookie syntax.

Not all clients can understand all of these formats. but you should use the newest one that is generally acceptable to your users' browsers.

CookieTracking directive

When the user track module is compiled in, and "CookieTracking on" is set, Apache will start sending 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, compiling mod_usertrack will not activate cookies.

Apache HTTP Server Version 1.3