path: root/docs/manual.xml

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<article>
  <articleinfo>
    <title>mod_log_sql Manual</title>
    <author>
      <firstname>Edward</firstname>
      <surname>Rudd</surname>
      <contrib>Conversion from Lyx to DocBook</contrib>
      <contrib>Current Maintainer</contrib>
      <authorblurb>
        <simpara>
          &EmailContact;
        </simpara>
      </authorblurb>
    </author>
    <author>
      <firstname>Christopher</firstname>
      <othername>B.</othername>
      <surname>Powell</surname>
      <contrib>Original documentation author.</contrib>
      <authorblurb>
        <simpara>
          <email>chris &lt;at&gt; grubbybaby &lt;dot&gt; com</email>
        </simpara>
      </authorblurb>
    </author>
    <copyright>
      <year>2001</year>
      <year>2002</year>
      <year>2003</year>
      <holder>Christopher B. Powell</holder>
    </copyright>
    <copyright>
      <year>2004</year>
      <year>2005</year>
      <year>2006</year>
      <holder>Edward Rudd</holder>
    </copyright>
    <revhistory>
      <revision>
        <revnumber>1.5</revnumber>
        <date>2006-11-04</date>
        <revremark>Added documentation about logio parameters and added DBParam Mysql driver parameters (including tabletype)</revremark>
      </revision>
      <revision>
        <revnumber>1.4</revnumber>
        <date>2006-02-13</date>
        <revremark>Added missing logformat types, switched to simplified docbook 1.1</revremark>
      </revision>
      <revision>
        <revnumber>1.3</revnumber>
        <date>2005-01-11</date>
        <revremark>Updated for mod_log_sql v1.100</revremark>
      </revision>
      <revision>
        <revnumber>1.2</revnumber>
        <date>2004-04-08</date>
        <revremark>Updated for mod_log_sql v1.97</revremark>
      </revision>
      <revision>
        <revnumber>1.1</revnumber>
        <date>2004-03-02</date>
        <revremark>Updated for mod_log_sql v1.96</revremark>
      </revision>
      <revision>
        <revnumber>1.0</revnumber>
        <date>2004-01-22</date>
        <revremark>Initial Conversion from Lyx to Docbook</revremark>
      </revision>
    </revhistory>
  </articleinfo>
  <section>
    <title>Introduction</title>
    <section tocstyle="fragment">
      <title>Summary</title>
      <para>
        This Apache module will permit you to log to a SQL database; it
        can log each access request as well as data associated with each
        request: cookies, notes, and inbound/outbound headers. Unlike
        logging to a flat text file -- which is standard in Apache -- a
        SQL-based log exhibits tremendous flexibility and power of data
        extraction. (See FAQ entry
        <xref linkend="FAQ.WhyLogToSQL" />
        for further discussion and examples of the advantages to SQL.)
      </para>
      <para>
        This module can either replace or happily coexist with
        mod_log_config, Apache's text file logging facility. In addition
        to being more configurable than the standard module, mod_log_sql
        is much more flexible.
      </para>
    </section>
    <section tocstyle="fragment">
      <title>Approach</title>
      <para>
        This project was formerly known as "mod_log_mysql." It was
        renamed "mod_log_sql" in order to reflect the project goal of
        database in-specificity. The module currently supports MySQL,
        but support for other database back-ends is underway.
      </para>
      <para>
        In order to save speed and overhead, links are kept alive in
        between queries. This module uses one dedicated SQL link per
        httpd child, opened by each child process when it is born. Among
        other things, this means that this module supports logging into
        only one MySQL server, and for now, also, only one SQL database.
        But that's a small tradeoff compared to the blinding speed of
        this module. Error reporting is robust throughout the module and
        will inform the administrator of database issues in the Apache
        ErrorLog for the server/virtual server.
      </para>
      <para>
        Virtual hosts are supported in the same manner they are in the
        regular logging modules. The administrator defines some basic
        'global' directives in the main server config, then defines more
        specific 'local' directives inside each VirtualHost stanza.
      </para>
      <para>
        A robust "preserve" capability has now been implemented. This
        permits the module to preserve any failed INSERT commands to a
        local file on its machine. In any situation that the database is
        unavailable -- e.g. the network fails or the database host is
        rebooted -- mod_log_sql will note this in the error log and
        begin appending its log entries to the preserve file (which is
        created with the user and group ID of the running Apache
        process, e.g. "nobody/nobody" on many Linux installations). When
        database availability returns, mod_log_sql seamlessly resumes
        logging to it. When convenient for the sysadmin, he/she can
        easily import the preserve file into the database because it is
        simply a series of SQL insert statements.
      </para>
    </section>
    <section tocstyle="fragment">
      <title>What gets logged by default?</title>
      <para>
        All the data that would be contained in the "Combined Log
        Format" is logged by default, plus a little extra. Your best bet
        is to begin by accepting this default, then later customize the
        log configuration based on your needs. The documentation of the
        run-time directives includes a full explanation of what you can
        log, including examples -- see section
        <xref endterm="Sect.ConfigReference.title"
          linkend="Sect.ConfigReference" />
        .
      </para>
    </section>
    <section tocstyle="fragment">
      <title>Miscellaneous Notes</title>
      <itemizedlist>
        <listitem>
          <para>
            Note which directives go in the 'main server config' and
            which directives apply to the 'virtual host config'. This is
            made clear in the directive documentation.
          </para>
        </listitem>
        <listitem>
          <para>
            The 'time_stamp' field is stored in an UNSIGNED INTEGER
            format, in the standard unix "seconds since the epoch"
            format. This is superior to storing the access time as a
            string due to size requirements: an UNSIGNED INT requires 4
            bytes, whereas an Apache date string (e.g.
            "18/Nov/2001:13:59:52 -0800") requires 26 bytes: those extra
            22 bytes become significant when multiplied by thousands of
            accesses on a busy server. Besides, an INT type is far more
            flexible for comparisons, etc.
          </para>
          <para>
            In MySQL 3.21 and above you can easily convert this to a
            human readable format using from_unixtime(), e.g.:
          </para>
          <programlisting>SELECT remote_host,request_uri,from_unixtime(time_stamp)
FROM access_log;</programlisting>
          <para>
            The enclosed perl program "make_combined_log.pl" extracts
            your access log in a format that is completely compatible
            with the Combined Log Format. You can then feed this to your
            favorite web log analysis tool.
          </para>
        </listitem>
        <listitem>
          <para>
            The table's string values can be CHAR or VARCHAR, at a
            length of your choice. VARCHAR is superior because it
            truncates long strings; CHAR types are fixed-length and will
            be padded with spaces, resulting in waste. Just like the
            time_stamp issue described above, that kind of space waste
            multiplies over thousands of records.
          </para>
        </listitem>
        <listitem>
          <para>
            Be careful not to go overboard setting fields to NOT NULL.
            If a field is marked NOT NULL then it must contain data in
            the INSERT statement, or the INSERT will fail. These
            mysterious failures can be quite frustrating and difficult
            to debug.
          </para>
        </listitem>
        <listitem>
          <para>
            When Apache logs a numeric field, it uses a '-' character to
            mean "not applicable," e.g. the number of bytes returned on
            a 304 (unchanged) request. Since '-' is an illegal character
            in an SQL numeric field, such fields are assigned the value
            0 instead of '-' which, of course, makes perfect sense
            anyway.
          </para>
        </listitem>
      </itemizedlist>
    </section>
    <section tocstyle="fragment">
      <title>Author / Maintainer</title>
      <para>
        The actual logging code was taken from the already existing flat
        file text modules, so all that credit goes to the Apache
        Software Foundation.
      </para>
      <para>
        The MySQL routines and directives were added by Zeev Suraski
        &lt;bourbon@netvision.net.il&gt;.
      </para>
      <para>
        All changes from 1.06+ and the new documentation were added by
        Chris Powell
        <email>chris &lt;at&gt; grubbybaby &lt;dot&gt; com</email>
        . It seems that the module had fallen into the "un-maintained"
        category -- it had not been updated since 1998 -- so Chris
        adopted it as the new maintainer.
      </para>
      <para>
        In December of 2003, Edward Rudd
        &EmailContact;
        porting the module to Apache 2.0, cleaning up the code,
        converting the documentation to DocBook, optimizing the main
        logging loop, and added the much anticipated database
        abstraction layer.
      </para>
      <para>
        As of February 2004, Chris Powell handed over maintenance of the
        module over to Edward Rudd. So you should contact Edward Rudd
        about the module from now on.
      </para>
    </section>
    <section id="Sect.MailingLists" tocstyle="fragment">
      <title id="Sect.MailingLists.title">Mailing Lists</title>
      <para>
        A general discussion and support mailing list is provided for
        mod_log_sq at lists.outoforder.cc. To subscribe to the mailing
        list send a blank e-mail to
        mod_log_sql-subscribe@lists.outoforder.cc. The list archives can
        be accessed via Gmane.org's mailng list gateway via any new
        reader
        <ulink
          url="news://news.gmane.org/gmane.comp.apache.mod-log-sql">
          news://news.gmane.org/gmane.comp.apache.mod-log-sql
        </ulink>
        , or via a web browser at
        <ulink
          url="http://news.gmane.org/gmane.comp.apache.mod-log-sql">
          http://news.gmane.org/gmane.comp.apache.mod-log-sql
        </ulink>
        .
      </para>
    </section>
  </section>
  <section>
    <title>Installation</title>
    <section tocstyle="fragment">
      <title>Requirements</title>
      <itemizedlist>
        <listitem>
          <para>
            A compatible system. mod_log_sql was authored and tested on
            systems based on Red Hat Linux (Red Hat, Mandrake), but the
            module should easily adapt to any modern distribution.
            mod_log_sql has also been ported successfully to Solaris and
            FreeBSD.
          </para>
        </listitem>
        <listitem>
          <para>
            Apache 1.3 or 2.0, 1.2 is no longer supported, but may still
            compile. Ideally you should already have successfully
            compiled Apache and understand the process, but this
            document tries to make it simple for beginners.
          </para>
        </listitem>
        <listitem>
          <para>
            The MySQL development headers. This package is called
            different things on different distributions. For example,
            Red Hat 6.x calls this RPM "MySQL-devel" whereas Mandrake
            calls it "libmysql10-devel." Both MySQL 3.23.x and 4.x are
            supported.
          </para>
        </listitem>
        <listitem>
          <para>
            MySQL &gt;= 3.23.15 configured, installed and running on
            either localhost or an accessible networked machine. You
            should already have a basic understanding of MySQL and how
            it functions.
          </para>
        </listitem>
        <listitem>
          <para>
            Optionally, if you want to be able to log SSL information
            such as keysize or cipher, you need OpenSSL and mod_ssl
            installed.
          </para>
        </listitem>
      </itemizedlist>
    </section>
    <section>
      <title>Compiling and Installing</title>
      <orderedlist>
        <listitem>
          <para>Unpack the archive into a working directory.</para>
          <programlisting>$ tar -xzf mod_log_sql-1.94.tar.gz
$ cd mod_log_sql-1.94</programlisting>
        </listitem>
        <listitem>
          <para>run configure to configure the source directory.</para>
          <programlisting>$ ./configure</programlisting>
          <para>
            The
            <filename>configure</filename>
            script should automatically detect all the required
            libraries and program if the are installed in standard
            locations.. If it returns an error, here is a description of
            the arguments you can specify when you run
            <filename>configure</filename>
            .
          </para>
          <variablelist>
            <varlistentry>
              <term>--with-apxs=/usr/sbin/apxs</term>
              <listitem>
                <para>
                  This is the full path to the apxs binary, or the
                  directory which contains the program. This program is
                  part of the Apache 1.3 and 2.0 installation.
                </para>
                <para>
                  The default is to search
                  <filename>/usr/bin/apxs</filename>
                  and
                  <filename>/usr/sbin/apxs</filename>
                  .
                </para>
                <para>
                  Specifying a directory here will search
                  $directory/apxs, $directory/bin/apxs, and
                  $directory/sbin/apxs
                </para>
                <para>
                  If you have more than one version of Apache installed,
                  you need to specify the correct apxs binary for the
                  one you wish to compile for.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>--with-mysql=/path/to/mysql</term>
              <listitem>
                <para>
                  This is the directory to search for the
                  <filename>libmysqlclient</filename>
                  library and the
                  <application>MySQL</application>
                  headers.
                </para>
                <para>
                  The default is to search
                  <filename>/usr/include</filename>
                  ,
                  <filename>/usr/include/mysql</filename>
                  ,
                  <filename>/usr/local/include</filename>
                  , and
                  <filename>/usr/local/include/mysql</filename>
                  for
                  <application>MySQL</application>
                  headers.. And
                  <filename>/usr/lib</filename>
                  .
                  <filename>/usr/lib/mysql</filename>
                  ,
                  <filename>/usr/local/lib</filename>
                  , and
                  <filename>/usr/local/lin/mysql</filename>
                  for the
                  <application>MySQL</application>
                  libraries.
                </para>
                <para>
                  Specifying this testargument will search
                  $directory/include and $directory/mysql for
                  <application>MySQL</application>
                  headers. And $directory/lib and $directory/lib/mysql
                  for
                  <application>MySQL</application>
                  libraries.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>--enable-ssl</term>
              <listitem>
                <para>
                  Specifying this argument will enable the search for
                  mod_ssl and SSL headers, and if found will enable
                  compilation of SSL support into mod_log_sql. SSL
                  support is compiled into a separate module that can be
                  loaded after the main mod_log_sql.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>--with-ssl-inc=/usr/include/openssl</term>
              <listitem>
                <para>
                  This is the path to the SSL toolkit header files that
                  were used to compile mod_ssl. If you want SSL support
                  you most likely need to specify this.
                </para>
                <para>
                  The default is to search
                  <filename>/usr/include</filename>
                  and
                  <filename>/usr/include/openssl</filename>
                  .
                </para>
                <para>
                  Specifying this argument will search that directory
                  for the SSL headers.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>--with-db-inc=/usr/include/db1</term>
              <listitem>
                <para>
                  This argument is only needed when compiling SSL
                  support for Apache 1.3, and needs to be the directory
                  which contains the ndbm.h header file. You can find
                  this by using
                </para>
                <programlisting>$ locate ndbm.h
/usr/include/db1/ndbm.h
/usr/include/gdbm/ndbm.h</programlisting>
                <para>
                  As far as I can tell, there is no difference as to
                  which you specify, but it should be the one that you
                  compiled mod_ssl with.
                </para>
                <para>
                  The default is
                  <filename>/usr/include/db1</filename>
                  , which should work on most systems.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>--disable-apachetest</term>
              <listitem>
                <para>
                  This will disable the apache version test. However
                  there is a side affect if you specify this where I
                  will not be able to determine which version of Apache
                  you are compiling for. So don't specify this.. If you
                  are having troubles with the script detecting your
                  Apache version, then send a bug report along with your
                  system OS version and versions of related packages.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>--disable-mysqltest</term>
              <listitem>
                <para>
                  This will disable the MySQL compile test. Specify this
                  if for some reason the test fail but you know you have
                  specified the correct directories. If mod_los_sql also
                  fails to compile report a bug along with your system
                  OS version and versions of related packages.
                </para>
              </listitem>
            </varlistentry>
          </variablelist>
        </listitem>
        <listitem>
          <para>
            Now compile the module with GNU make. You may have to
            specify gmake on some systems like FreeBSD.
          </para>
          <programlisting>$ gmake</programlisting>
        </listitem>
        <listitem>
          <para>
            If there were no errors, you can now install the module(s).
            If you compiled as a non-root user you may need to switch
            users with
            <application>su</application>
            or
            <application>sudo</application>
            .
          </para>
          <programlisting>$ su -c "gmake install"
Password:</programlisting>
        </listitem>
        <listitem>
          <para>
            Now edit your Apache configuration and load the modules.
          </para>
          <note>
            <itemizedlist>
              <listitem>
                <para>
                  If you are loading the SSL logging module, you need to
                  make sure it is loaded after mod_ssl and mod_log_sql.
                </para>
              </listitem>
              <listitem>
                <para>
                  If you have previously used mod_log_sql version 1.18,
                  the name of the module has changed from sql_log_module
                  to log_sql_module (the first parameter to LoadModule)
                </para>
              </listitem>
              <listitem>
                <para>
                  If you are upgrading from any release earlier than
                  1.97 you need to add an extra LoadModule directive to
                  load the database driver (ie mysql).
                </para>
              </listitem>
            </itemizedlist>
          </note>
          <orderedlist>
            <listitem>
              <para>
                Insert these lines to either the main
                <filename>httpd.conf</filename>
                or a file included via an include directive.
              </para>
              <programlisting>LoadModule log_sql_module modules/mod_log_sql.so
LoadModule log_sql_mysql_module modules/mod_log_sql_mysql.so
&lt;IfModule mod_ssl.c&gt;
LoadModule log_sql_ssl_module moduels/mod_log_sql_ssl.so
&lt;/IfModule&gt;</programlisting>
              <note>
                <para>
                  If you did not compile SSL support in mod_log_sql, do
                  not include the lines between the &lt;IfModule&gt;
                  directives.
                </para>
              </note>
            </listitem>
            <listitem>
              <para>
                If you are using Apache 1.3 you may need add these lines
                later in the configuration.
              </para>
              <programlisting>AddModule mod_log_sql.c
AddModule mod_log_sql_mysql.c
&lt;IfModule mod_ssl.c&gt;
AddModule mod_log_sql_ssl.c
&lt;/IfModule&gt;</programlisting>
              <note>
                <para>
                  If you did not compile SSL support in mod_log_sql, do
                  not include the lines between the &lt;IfModule&gt;
                  directives.
                </para>
              </note>
            </listitem>
          </orderedlist>
        </listitem>
      </orderedlist>
    </section>
  </section>
  <section id="Sect.Configuration">
    <title id="Sect.Configuration.title">Configuration</title>
    <section id="Sect.Preperation">
      <title id="Sect.Preperation.title">
        Preparing MySQL for logging
      </title>
      <para>
        You have to prepare the database to receive data from
        <application>mod_log_sql</application>
        , and set up run-time directives in
        <filename>httpd.conf</filename>
        to control how and what
        <application>mod_log_sql</application>
        logs.
      </para>
      <para>
        This section will discuss how to get started with a basic
        configuration. Full documentation of all available run-time
        directives is available in section
        <xref endterm="Sect.ConfigReference.title"
          linkend="Sect.ConfigReference" />
        .
      </para>
      <orderedlist>
        <listitem>
          <para>
            mod_log_sql can make its own tables on-the-fly, or you can
            pre-make the tables by hand. The advantage of letting the
            module make the tables is ease-of-use, but for raw
            performance you will want to pre-make the tables in order to
            save some overhead. In this basic setup we'll just let the
            module create tables for us.
          </para>
        </listitem>
        <listitem>
          <para>
            We still need to have a logging database created and ready,
            so run the MySQL command line client and create a database:
          </para>
          <programlisting># mysql -uadmin -p
Enter password:
mysql&gt; create database apachelogs;</programlisting>
        </listitem>
        <listitem id="Item.CreateTable">
          <para>
            If you want to hand-create the tables, run the enclosed
            'create-tables' SQL script as follows ("create_tables.sql"
            needs to be in your current working directory).
          </para>
          <programlisting>mysql&gt; use apachelogs
Database changed
mysql&gt; source create_tables.sql</programlisting>
        </listitem>
        <listitem>
          <para>
            Create a specific
            <application>MySQL</application>
            userid that
            <application>httpd</application>
            will use to authenticate and enter data. This userid need
            not be an actual Unix user. It is a userid internal to
            <application>MySQL</application>
            with specific privileges. In the following example command,
            "apachelogs" is the database, "loguser" is the userid to
            create, "my.apachemachine.com" is the name of the Apache
            machine, and "l0gger" is the password to assign. Choose
            values that are different from these examples.
          </para>
          <programlisting>mysql&gt; grant insert,create on apachelogs.* to loguser@my.apachemachine.com identified by 'l0gger';</programlisting>
        </listitem>
        <listitem>
          <para>
            You may be especially security-paranoid and want "loguser"
            to not have "create" capability within the "apachelogs"
            database. You can disable that privilege, but the cost is
            that you will not be able to use the module's on-the-fly
            table creation feature. If that cost is acceptable,
            hand-create the tables as described in step
            <xref linkend="Item.CreateTable" />
            and use the following GRANT statement instead of the one
            above:
          </para>
          <programlisting>mysql&gt; grant insert on apachelogs.* to loguser@my.apachemachine.com identified by 'l0gger';</programlisting>
        </listitem>
        <listitem id="Item.EnableLogging">
          <para>
            Enable full logging of your
            <application>MySQL</application>
            daemon (at least temporarily for debugging purposes) if you
            don't do this already. Edit /etc/my.cnf and add the
            following line to your [mysqld] section:
          </para>
          <programlisting>log=/var/log/mysql-messages</programlisting>
          <para>
            Then restart
            <application>MySQL</application>
          </para>
          <programlisting># /etc/rc.d/init.d/mysql restart</programlisting>
        </listitem>
      </orderedlist>
    </section>
    <section>
      <title>A very basic logging setup in Apache</title>
      <orderedlist>
        <listitem>
          <para>
            Tell the module what database to use and the appropriate
            authentication information.
          </para>
          <para>
            So, edit httpd.conf and insert the following lines somewhere
            after any LoadModule / AddModule statements. Make sure these
            statements are "global," i.e. not inside any VirtualHost
            stanza. You will also note that you are embedding a password
            in the file. Therefore you are advised to "chmod 660
            httpd.conf" to prevent unauthorized regular users from
            viewing your database user and password.
          </para>
          <para>
            Use the
            <application>MySQL</application>
            database called "apachelogs" running on "dbmachine.foo.com".
            Use username "loguser" and password "l0gg3r" to authenticate
            to the database. Permit the module create tables for us.
          </para>
          <example>
            <title>Basic Example</title>
            <programlisting>LogSQLLoginInfo mysql://loguser:l0gg3r@dbmachine.foo.com/apachelogs
LogSQLCreateTables on</programlisting>
          </example>
          <para>
            If your database resides on localhost instead of another
            host, specify the MySQL server's socket file as follows:
          </para>
          <programlisting>LogSQLDBParam socketfile /your/path/to/mysql.sock</programlisting>
          <para>
            If your database is listening on a port other than 3306,
            specify the correct TCP port as follows:
          </para>
          <programlisting>LogSQLDBParam port 1234</programlisting>
        </listitem>
        <listitem>
          <para>
            The actual logging is set up on a virtual-host-by-host
            basis. So, skip down to the virtual host you want to set up.
            Instruct this virtual host to log entries to the table
            "access_log" by inserting a LogSQLTransferLogTable
            directive. (The LogSQLTransferLogTable directive is the
            minimum required to log -- other directives that you will
            learn about later simply tune the module's behavior.)
          </para>
          <programlisting>&lt;VirtualHost 1.2.3.4&gt;
 [snip]
 LogSQLTransferLogTable access_log
 [snip]
&lt;/VirtualHost&gt;</programlisting>
        </listitem>
        <listitem>
          <para>Restart apache.</para>
          <programlisting># /etc/rc.d/init.d/httpd stop
# /etc/rc.d/init.d/httpd start</programlisting>
        </listitem>
      </orderedlist>
    </section>
    <section>
      <title>Testing the basic setup</title>
      <orderedlist>
        <listitem>
          <para>
            Visit your web site in a browser to trigger some hits, then
            confirm that the entries are being successfully logged:
          </para>
          <programlisting># mysql -hdbmachine.foo.com -umysqladmin -p -e "SELECT * FROM access_log" apachelogs
Enter password:</programlisting>
          <para>
            Several lines of output should follow, corresponding to your
            hits on the site. You now have basic functionality. Don't
            disable your regular Apache logs until you feel comfortable
            that the database is behaving as you'd like and that things
            are going well. If you do not see any entries in the
            access_log, please consult section
            <xref linkend="FAQ.NothingLogged" />
            of the FAQ on how to debug and fix the situation.
          </para>
        </listitem>
        <listitem>
          <para>
            You can now activate the advanced features of mod_log_sql,
            which are described in the next section.
          </para>
        </listitem>
      </orderedlist>
    </section>
    <section>
      <title>How to tune logging with run-time directives</title>
      <section tocstyle="fragment">
        <title>Instructing the module what to log</title>
        <para>
          The most basic directive for the module is
          LogSQLTransferLogFormat, which tells the module which
          information to send to the database; logging to the database
          will not take place without it. Place a
          LogSQLTransferLogFormat directive in the VirtualHost stanza of
          each virtual host that you want to activate.
        </para>
        <para>
          After LogSQLTransferLogFormat you supply a string of
          characters that tell the module what information to log. In
          the configuration directive reference (section
          <xref linkend="Conf.LogSQLTransferLogFormat" />
          ) there is a table which clearly defines all the possible
          things to log. Let's say you want to log only the "request
          time," the "remote host," and the "request"; you'd use:
        </para>
        <programlisting>LogSQLTransferLogFormat hUS</programlisting>
        <para>But a more appropriate string to use is</para>
        <programlisting>LogSQLTransferLogFormat AbHhmRSsTUuv</programlisting>
        <para>
          which logs all the information required to be compatible with
          the Combined Log Format (CLF).
        </para>
        <para>
          If you don't choose to log everything that is available,
          that's fine. Fields in the unused columns in your table will
          simply contain NULL.
        </para>
        <para>
          Some of the LogSQLTransferLogFormat characters require a
          little extra configuration:
        </para>
        <itemizedlist>
          <listitem>
            <para>
              If you specify 'c' to indicate that you want to log the
              cookie value, you must also tell the module which cookie
              you mean by using LogSQLWhichCookie -- after all, there
              could be many cookies associated with a given request.
              Fail to specify LogSQLWhichCookie, and no cookie
              information at all will be logged.
            </para>
          </listitem>
          <listitem>
            <para>
              If you specify 'M' to indicate that you want to log the
              machine ID, you must also tell the module this machine's
              identity using the LogSQLMachineID directive. Fail to
              specify LogSQLMachineID, and a simple '-' character will
              be logged in the machine_id column.
            </para>
          </listitem>
        </itemizedlist>
      </section>
      <section id="Sect.Ignore">
        <title id="Sect.Ignore.title">
          Instructing the module what NOT to log using filtering
          directives
        </title>
        <para>
          One "accept" and two "ignore" directives allow you to
          fine-tune what the module should not log. These are very handy
          for keeping your database as uncluttered as possible and
          keeping your statistics free of unneeded numbers. Think of
          each one as a gatekeeper.
        </para>
        <para>
          <emphasis>
            It is important to remember that each of these three
            directives is purely optional. mod_log_sql's default is to
            log everything.
          </emphasis>
        </para>
        <para>
          When a request comes in, the contents of LogSQLRequestAccept
          are evaluated first. This optional, "blanket" directive lets
          you specify that only certain things are to be accepted for
          logging, and everything else discarded. Because it is
          evaluated before LogSQLRequestIgnore and LogSQLRemhostIgnore
          it can halt logging before those two filtering directives "get
          their chance."
        </para>
        <para>
          Once a request makes it past LogSQLRequestAccept, it still can
          be excluded based on LogSQLRemhostIgnore and
          LogSQLRequestIgnore. A good way to use LogSQLRemhostIgnore is
          to prevent the module from logging the traffic that your
          internal hosts generate. LogSQLRequestIgnore is great for
          preventing things like requests for "favicon.ico" from
          cluttering up your database, as well as excluding the various
          requests that worms make, etc.
        </para>
        <para>
          You can specify a series of strings after each directive. Do
          not use any type of globbing or regular-expression syntax --
          each string is considered a match
          <emphasis>
            if it is a substring of the larger request or remote-host;
            the comarison is case-sensitive
          </emphasis>
          . This means that "LogSQLRemhostIgnore micro" will ignore
          requests from "microsoft.com," "microworld.net,"
          "mymicroscope.org," etc. "LogSQLRequestIgnore gif" will
          instruct the module to ignore requests for "leftbar.gif,"
          "bluedot.gif" and even "giftwrap.jpg" -- but "RED.GIF" and
          "Tree.Gif" would still get logged because of case sensitivity.
        </para>
        <para>A summary of the decision flow:</para>
        <orderedlist>
          <listitem>
            <para>
              If LogSQLRequestAccept exists and a request does not match
              anything in that list, it is discarded.
            </para>
          </listitem>
          <listitem>
            <para>
              If a request matches anything in the LogSQLRequestIgnore
              list, it is discarded.
            </para>
          </listitem>
          <listitem>
            <para>
              If a reqiest matches anything in the LogSQLRemhostIgnore
              list, it is discarded.
            </para>
          </listitem>
          <listitem>
            <para>Otherwise the request is logged.</para>
          </listitem>
        </orderedlist>
        <para>
          This means that you can have a series of directives similar to
          the following:
        </para>
        <programlisting>LogSQLRequestAccept .html .gif .jpg
LogSQLRequestIgnore statistics.html bluedot.jpg</programlisting>
        <para>
          So the first line instructs the module to only log files with
          html, gif and jpg suffixes; requests for "formail.cgi" and
          "shopping-cart.pl" will never be considered for logging.
          ("LeftArrow.JPG" will also never be considered for logging --
          remember, the comparison is case sensitive.) The second line
          prunes the list further -- you never want to log requests for
          those two objects.
        </para>
        <note role="tip">
          <itemizedlist>
            <listitem>
              <para>
                If you want to match all the hosts in your domain such
                as "host1.corp.foo.com" and "server.dmz.foo.com", simply
                specify:
              </para>
              <programlisting>LogSQLRemhostIgnore foo.com</programlisting>
            </listitem>
            <listitem>
              <para>
                A great way to catch the vast majority of worm-attack
                requests and prevent them from being logged is to
                specify:
              </para>
              <programlisting>LogSQLRequestIgnore root.exe cmd.exe default.ida</programlisting>
            </listitem>
            <listitem>
              <para>
                To prevent the logging of requests for common graphic
                types, make sure to put a '.' before the suffix to avoid
                matches that you didn't intend:
              </para>
              <programlisting>LogSQLRequestIgnore .gif .jpg</programlisting>
            </listitem>
          </itemizedlist>
        </note>
      </section>
    </section>
    <section>
      <title>Advanced logging scenarios</title>
      <section tocstyle="fragment">
        <title>Using the module in an ISP environment</title>
        <para>mod_log_sql has three basic tiers of operation:</para>
        <orderedlist>
          <listitem>
            <para>
              The administrator creates all necessary tables by hand and
              configures each Apache VirtualHost by hand.
              (LogSQLCreateTables Off)
            </para>
          </listitem>
          <listitem>
            <para>
              The module is permitted to create necessary tables
              on-the-fly, but the administrator configures each Apache
              VirtualHost by hand. (LogSQLCreateTables On)
            </para>
          </listitem>
          <listitem>
            <para>
              The module is permitted to create all necessary tables and
              to make intelligent, on-the-fly configuration of each
              VirtualHost. (LogSQLMassVirtualHosting On)
            </para>
          </listitem>
        </orderedlist>
        <para>
          Many users are happy to use the module in its most minimal
          form: they hand-create any necessary tables (using
          "create_tables.sql"), and they configure each VirtualHost by
          hand to suit their needs. However, some administrators need
          extra features due to a large and growing number of
          VirtualHosts. The LogSQLMassVirtualHosting directive activates
          module capabilities that make it far easier to manage an ISP
          environment, or any situation characterized by a large and
          varying number of virtual servers.
        </para>
        <itemizedlist>
          <listitem>
            <para>
              the on-the-fly table creation feature is activated
              automatically
            </para>
          </listitem>
          <listitem>
            <para>
              the transfer log table name is dynamically set from the
              virtual host's name (example: a virtual host
              "www.grubbybaby.com" gets logged to table
              "access_www_grubbybaby_com")
            </para>
          </listitem>
        </itemizedlist>
        <para>
          There are numerous benefits. The admin will not need to create
          new tables for every new VirtualHost. (Although the admin will
          still need to drop the tables of virtual hosts that are
          removed.) The admin will not need to set
          LogSQLTransferLogTable for each virtual host -- it will be
          configured automatically based on the host's name. Because
          each virtual host will log to its own segregated table, data
          about one virtual server will segregate from others; an admin
          can grant users access to the tables they need, and they will
          be unable to view data about another user's virtual host.
        </para>
        <para>
          In an ISP scenario the admin is likely to have a cluster of
          many front-end webservers logging to a back-end database.
          mod_log_sql has a feature that permits analysis of how well
          the web servers are loadbalancing: the LogSQLMachineID
          directive. The administrator uses this directive to assign a
          unique identifier to each machine in the web cluster, e.g.
          "LogSQLMachineID web01," "LogSQLMachineID web02," etc. Used in
          conjunction with the 'M' character in LogSQLTransferLogFormat,
          each entry in the SQL log will include the machine ID of the
          machine that created the entry. This permits the administrator
          to count the entries made by each particular machine and
          thereby analyze the front-end loadbalancing algorithm.
        </para>
      </section>
      <section id="Sect.MultiTable">
        <title id="Sect.MultiTable.title">
          Logging many-to-one data in separate tables
        </title>
        <para>
          A given HTTP request can have a one-to-many relationship with
          certain kinds of data. For example, a single HTTP request can
          have 4 cookies, 3 headers and 5 "mod_gzip" notes associated
          with it. mod_log_sql is capable of logging these relationships
          due to the elegance of SQL relational data.
        </para>
        <para>
          You already have a single table containing access requests.
          One of the columns in that table is 'id' which is intended to
          contain the unique request ID supplied by the standard Apache
          module mod_unique_id -- all you need to do is compile in that
          module and employ the LogSQLTransferLogFormat character 'I'.
          Thereafter, each request gets a unique ID that can be thought
          of as a primary key within the database, useful for joining
          multiple tables. So let's envision several new tables: a notes
          table, a cookies table, and a table for inbound and outbound
          headers.
        </para>
        <table>
          <title>&lt;tblAcc&gt;access_log</title>
          <tgroup cols="6">
            <colspec colname="1" />
            <colspec colname="2" />
            <colspec colname="3" />
            <colspec colname="4" />
            <colspec colname="5" colwidth="40" />
            <colspec colname="6" colwidth="70" />
            <thead>
              <row>
                <entry colname="1">id</entry>
                <entry colname="2">remote_host</entry>
                <entry colname="3">request_uri</entry>
                <entry colname="4">time_stamp</entry>
                <entry colname="5">status</entry>
                <entry colname="6">bytes_sent</entry>
              </row>
            </thead>
            <tbody>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">zerberus.aiacs.net</entry>
                <entry colname="3">/mod_log_sql/index.html</entry>
                <entry colname="4">1022493617</entry>
                <entry colname="5">200</entry>
                <entry colname="6">2215</entry>
              </row>
            </tbody>
          </tgroup>
        </table>
        <table>
          <title>&lt;tblNotes&gt;notes_log</title>
          <tgroup cols="3">
            <colspec colname="1" />
            <colspec colname="2" />
            <colspec colname="3" colwidth="30" />
            <thead>
              <row>
                <entry colname="1">id</entry>
                <entry colname="2">item</entry>
                <entry colname="3">val</entry>
              </row>
            </thead>
            <tbody>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">mod_gzip_result</entry>
                <entry colname="3">OK</entry>
              </row>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">mod_gzip_compression_ratio</entry>
                <entry colname="3">69</entry>
              </row>
            </tbody>
          </tgroup>
        </table>
        <table>
          <title>&lt;tblHdr&gt;headers_log</title>
          <tgroup cols="3">
            <colspec colname="1" colnum="1" />
            <colspec colname="2" colnum="2" />
            <colspec colname="3" colnum="3" />
            <thead>
              <row>
                <entry colname="1">id</entry>
                <entry colname="2">item</entry>
                <entry colname="3">val</entry>
              </row>
            </thead>
            <tbody>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">Content-Type</entry>
                <entry colname="3">text/html</entry>
              </row>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">Accept-Encoding</entry>
                <entry colname="3">gzip, deflate</entry>
              </row>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">Expires</entry>
                <entry colname="3">Tue, 28 May 2002 10:00:18 GMT</entry>
              </row>
              <row>
                <entry colname="1">PPIDskBRH30AAGPtAsg</entry>
                <entry colname="2">Cache-Control</entry>
                <entry colname="3">max-age=86400</entry>
              </row>
            </tbody>
          </tgroup>
        </table>
        <para>
          We have a certain request, and its unique ID is
          "PPIDskBRH30AAGPtAsg". Within each separate table will be
          multiple entries with that request ID: several cookie entries,
          several header entries, etc. As you can see in tables
          [tblAcc], [tblNotes] and [tblHdr], you have a one-to-many
          relationship for request PPIDskBRH30AAGPtAsg: that one access
          has two associated notes and four associated headers. You can
          extract this data easily using the power of SQL's "select"
          statement and table joins. To see the notes associated with a
          particular request:
        </para>
        <programlisting>SELECT a.remote_host, a.request_uri, n.item, n.val
FROM access_log a JOIN notes_log n ON a.id=n.id
WHERE a.id='PPIDskBRH30AAGPtAsg';</programlisting>
        <table>
          <title>access_log joined to notes_log</title>
          <tgroup cols="4">
            <colspec colname="1" />
            <colspec colname="2" />
            <colspec colname="3" />
            <colspec colname="4" colwidth="30" />
            <thead>
              <row>
                <entry colname="1">remote_host</entry>
                <entry colname="2">request_uri</entry>
                <entry colname="3">item</entry>
                <entry colname="4">val</entry>
              </row>
            </thead>
            <tbody>
              <row>
                <entry colname="1">zerberus.aiacs.net</entry>
                <entry colname="2">/mod_log_sql/index.html</entry>
                <entry colname="3">mod_gzip_result</entry>
                <entry colname="4">OK</entry>
              </row>
              <row>
                <entry colname="1">zerberus.aiacs.net</entry>
                <entry colname="2">/mod_log_sql/index.html</entry>
                <entry colname="3">mod_gzip_compression_ratio</entry>
                <entry colname="4">69</entry>
              </row>
            </tbody>
          </tgroup>
        </table>
        <para>
          Naturally you can craft similar statements for the outboud
          headers, inbound headers and cookies, all of which can live in
          separate tables. Your statements are limited in power only by
          your skill with SQL.
        </para>
        <para>
          In order to use this capability of mod_log_sql, you must do
          several things.
        </para>
        <itemizedlist>
          <listitem>
            <para>
              Compile mod_unique_id into Apache (statically or as a
              DSO). mod_log_sql employs the unique request ID that
              mod_unique_id provides in order to key between the
              separate tables. You can still log the data without
              mod_unqiue_id, but it will be completely uncorrelated and
              you will have no way to discern any meaning.
            </para>
          </listitem>
          <listitem>
            <para>
              Create the appropriate tables. This will be done for you
              if you permit mod_log_sql to create its own tables using
              LogSQLCreateTables On, or if you use the enclosed
              "create_tables.sql" script.
            </para>
          </listitem>
          <listitem>
            <para>
              Create a SQL index on the "id" column. Without this index,
              table joins will be deathly slow. I recommend you consult
              the MySQL documentation on the proper way to create a
              column index if you are not familiar with this operation.
            </para>
          </listitem>
          <listitem>
            <para>
              Within each appropriate VirtualHost stanza, use the
              LogSQLWhich* and LogSQL*LogTable directives to tell the
              module what and where to log the data. In the following
              example, I have overridden the name for the notes table
              whereas I have left the other table names at their
              defaults. I have then specified the cookies, headers and
              notes that interest me. (And as you can see, these
              directives do not require me to add any characters to
              LogSQLTransferLogTable.)
            </para>
            <programlisting>&lt;VirtualHost 216.231.36.128&gt;
 (snip)
 LogSQLNotesLogTable notestable
 LogSQLWhichCookies bluecookie redcookie greencookie
 LogSQLWhichNotes mod_gzip_result mod_gzip_compression_ratio
 LogSQLWhichHeadersOut Expires Content-Type Cache-Control
 LogSQLWhichHeadersIn User-Agent Accept-Encoding Host
 (snip)
&lt;/VirtualHost&gt;</programlisting>
          </listitem>
        </itemizedlist>
      </section>
      <section>
        <title>Using the same database for production and test</title>
        <para>
          Although sub-optimal, it is not uncommon to use the same
          back-end database for the "production" webservers as well as
          the "test" webservers (budgetary constraints, rack-space
          limits, etc.). Furthermore, an administrator in this situation
          may be unable to use LogSQLRemhostIgnore to exclude requests
          from the test servers -- perhaps the generated entries are
          genuinely useful for analytical or QA purposes, but their
          value after analysis is minimal.
        </para>
        <para>
          It is wasteful and potentially confusing to permit this
          internal test data to clutter the database, and a solution to
          the problem is the proper use of the LogSQLMachineID
          directive. Assume a scenario where the production webservers
          have IDs like "web01," "web02," and so on -- and the test
          webservers have IDs like "test01," "test02," etc. Because
          entries in the log database are distinguished by their source
          machine, an administrator may purge unneeded test data from
          the access log as follows:
        </para>
        <programlisting>DELETE FROM access_log WHERE machine_id like 'test%';</programlisting>
      </section>
      <section id="Sect.DelayedInsert">
        <title id="Sect.DelayedInsert.title">
          Optimizing for a busy database
        </title>
        <para>
          A busy MySQL database will have SELECT statements running
          concurrently with INSERT and UPDATE statements. A long-running
          SELECT can in certain circumstances block INSERTs and
          therefore block mod_log_sql. A workaround is to enable
          mod_log_sql for "delayed inserts," which are described as
          follows in the MySQL documentation.
        </para>
        <para>
          The DELAYED option for the INSERT statement is a
          MySQL-specific option that is very useful if you have clients
          that can't wait for the INSERT to complete. This is a common
          problem when you use MySQL for logging and you also
          periodically run SELECT and UPDATE statements that take a long
          time to complete. DELAYED was introduced in MySQL Version
          3.22.15. It is a MySQL extension to ANSI SQL92.
        </para>
        <para>
          INSERT DELAYED only works with ISAM and MyISAM tables. Note
          that as MyISAM tables supports concurrent SELECT and INSERT,
          if there is no free blocks in the middle of the data file, you
          very seldom need to use INSERT DELAYED with MyISAM.
        </para>
        <para>
          When you use INSERT DELAYED, the client will get an OK at once
          and the row will be inserted when the table is not in use by
          any other thread.
        </para>
        <para>
          Another major benefit of using INSERT DELAYED is that inserts
          from many clients are bundled together and written in one
          block. This is much faster than doing many separate inserts.
        </para>
        <para>The general disadvantages of delayed inserts are</para>
        <orderedlist>
          <listitem>
            <para>
              The queued rows are only stored in memory until they are
              inserted into the table. If mysqld dies unexpectedly, any
              queued rows that were not written to disk are lost.
            </para>
          </listitem>
          <listitem>
            <para>
              There is additional overhead for the server to handle a
              separate thread for each table on which you use INSERT
              DELAYED.
            </para>
          </listitem>
        </orderedlist>
        <note role="warning">
          <para>
            The MySQL documentation concludes, "This means that you
            should only use INSERT DELAYED when you are really sure you
            need it!" Furthermore, the current state of error return
            from a failed INSERT DELAYED seems to be in flux, and may
            behave in unpredictable ways between different MySQL
            versions. See FAQ entry
            <xref linkend="FAQ.DelayedInsert" />
            -- you have been warned.
          </para>
        </note>
        <para>
          If you are experiencing issues which could be solved by
          delayed inserts, then set LogSqlDelayedInserts On in the
          <filename>httpd.conf</filename>
          . All regular INSERT statements are now INSERT DELAYED, and
          you should see no more blocking of the module.
        </para>
      </section>
    </section>
    <section id="Sect.ConfigReference">
      <title id="Sect.ConfigReference.title">
        Configuration Directive Reference
      </title>
      <para>
        It is imperative that you understand which directives are used
        only once in the main server config, and which are used inside
        VirtualHost stanzas and therefore multiple times within
        httpd.conf. The "context" listed with each entry informs you of
        this.
      </para>
      <section tocstyle="fragment">
        <title>DataBase Configuration</title>
        <variablelist>
          <varlistentry>
            <term>LogSQLLoginInfo</term>
            <listitem>
              <cmdsynopsis>
                <command>LogSQLLoginInfo</command>
                <arg choice="req">
                  <replaceable>connection URI</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLLoginInfo
                mysql://logwriter:passw0rd@foobar.baz.com/Apache_log
              </simpara>
              <simpara>Context: main server config</simpara>
              <para>
                Defines the basic connection URI to connect to the
                database with. The format of the connection URI is
              </para>
              <simpara>
                driver://username[:password]@hostname[:port]/database
              </simpara>
              <variablelist>
                <varlistentry>
                  <term>driver</term>
                  <listitem>
                    <simpara>
                      The database driver to use (mysql, pgsql, etc..)
                    </simpara>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term>username</term>
                  <listitem>
                    <simpara>
                      The database username to login with INSERT
                      privileges on the logging table defined in
                      LogSQLtransferLogTable.
                    </simpara>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term>password</term>
                  <listitem>
                    <simpara>
                      The password to use for username, and can be
                      omitted if there is no password.
                    </simpara>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term>hostname</term>
                  <listitem>
                    <simpara>
                      The hostname or Ip address of the Database
                      machine, ans is simple "localhost" if the database
                      lives on the same machine as Apache.
                    </simpara>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term>port</term>
                  <listitem>
                    <simpara>
                      Port on hostname to connect to the Database, if
                      not specified use the default port for the
                      database.
                    </simpara>
                  </listitem>
                </varlistentry>
                <varlistentry>
                  <term>database</term>
                  <listitem>
                    <simpara>
                      The database to connect to on the server.
                    </simpara>
                  </listitem>
                </varlistentry>
              </variablelist>
              <note>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
                <para>
                  This directive Must be defined for logging to be
                  enabled.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLDBParam</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLDBParam</command>
                <arg choice="req">
                  <replaceable>parameter-name</replaceable>
                </arg>
                <arg choice="req">
                  <replaceable>value</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLDBParam socketfile
                /var/lib/mysql/mysql.socket
              </simpara>
              <simpara>Context: main server config</simpara>
              <para>
                This is the new method of specifying Database connection
                credentials and settings. This is used to define
                database driver specific options. For a list of options
                read the documentation for each specific database
                driver.
              </para>
              <table>
                <title>MySQL Driver parameters</title>
                <tgroup cols="5">
                  <colspec colname="1" colnum="1" />
                  <colspec colname="2" colnum="2" />
                  <colspec colname="3" colnum="3" />
                  <thead>
                    <row>
                      <entry colname="1">Parameter</entry>
                      <entry colname="2">Meaning</entry>
                      <entry colname="3">Default</entry>
                    </row>
                  </thead>
                  <tbody>
                    <row>
                      <entry colname="1">hostname</entry>
                      <entry colname="2">MySQL Server hostname</entry>
                      <entry colname="3">none (use LogSQLLoginInfo to set)</entry>
                    </row>
                    <row>
                      <entry colname="1">username</entry>
                      <entry colname="2">The username to log in with</entry>
                      <entry colname="3">none (use LogSQLLoginInfo to set)</entry>
                    </row>
                    <row>
                      <entry colname="1">password</entry>
                      <entry colname="2">The password to use</entry>
                      <entry colname="3">none (use LogSQLLoginInfo to set)</entry>
                    </row>
                    <row>
                      <entry colname="1">database</entry>
                      <entry colname="2">Which database to connect to</entry>
                      <entry colname="3">none (use LogSQLLoginInfo to set)</entry>
                    </row>
                    <row>
                      <entry colname="1">port</entry>
                      <entry colname="2">The TCP port to connect to the MySQL server over</entry>
                      <entry colname="3">3306 (use LogSQLLoginInfo to set)</entry>
                    </row>
                    <row>
                      <entry colname="1">socketfile</entry>
                      <entry colname="2">The MySQL Unix socket file to use</entry>
                      <entry colname="3">none</entry>
                    </row>
                    <row>
                      <entry colname="1">tabletype</entry>
                      <entry colname="2">MySQL Table Engine to use</entry>
                      <entry colname="3">MySQL server default</entry>
                    </row>
                  </tbody>
                </tgroup>
              </table>
              <note>
                <para>
                  Each parameter-name may only be defined once.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLCreateTables</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLCreateTables</command>
                <arg choice="req">flag</arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLCreateTables On</simpara>
              <simpara>Default: Off</simpara>
              <simpara>Context: main server config</simpara>
              <para>
                mod_log_sql has the ability to create its tables
                on-the-fly. The advantage to this is convenience: you
                don't have to execute any SQL by hand to prepare the
                table. This is especially helpful for people with lots
                of virtual hosts (who should also see the
                LogSQLMassVirtualHosting directive).
              </para>
              <para>
                There is a slight disadvantage: if you wish to activate
                this feature, then the userid specified in
                LogSQLLoginInfo must have CREATE privileges on the
                database. In an absolutely paranoid, locked-down
                situation you may only want to grant your mod_log_sql
                user INSERT privileges on the database; in that
                situation you are unable to take advantage of
                LogSQLCreateTables. But most people -- even the very
                security-conscious -- will find that granting CREATE on
                the logging database is reasonable.
              </para>
              <note>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLForcePreserve</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLForcePreserve</command>
                <arg choice="req">flag</arg>
              </cmdsynopsis>
              <simpara>Example: LogForcePreserve On</simpara>
              <simpara>Default: Off</simpara>
              <simpara>Context: main server config</simpara>
              <para>
                You may need to perform debugging on your database and
                specifically want mod_log_sql to make no attempts to log
                to it. This directive instructs the module to send all
                its log entries directly to the preserve file and to
                make no database INSERT attempts.
              </para>
              <para>
                This is presumably a directive for temporary use only;
                it could be dangerous if you set it and forget it, as
                all your entries will simply pile up in the preserve
                file.
              </para>
              <note>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLDisablePreserve</term>
            <listitem>
              <cmdsynopsis>
                <command>LogSQLDisablePreserve</command>
                <arg choice="req">flag</arg>
              </cmdsynopsis>
              <simpara>Example: LogDisablePreserve On</simpara>
              <simpara>Default: Off</simpara>
              <simpara>Context; main server config</simpara>
              <para>
                This option can be enabled to completely disable the
                preserve file fail back. This may be useful for servers
                where the file-system is read-only.
              </para>
              <para>
                If the database is not available those log entries will
                be lost.
              </para>
              <note>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLMachineID</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLMachineID</command>
                <arg choice="req">machineID</arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLMachineID web01</simpara>
              <simpara>Context: main server config</simpara>
              <para>
                If you have a farm of webservers then you may wish to
                know which particular machine made each entry; this is
                useful for analyzing your load-balancing methodology.
                LogSQLMachineID permits you to distinguish each
                machine's entries if you assign each machine its own
                LogSQLMachineID: for example, the first webserver gets
                ``LogSQLMachineID web01,'' the second gets
                ``LogSQLMachineID web02,'' etc.
              </para>
              <note>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQlPreserveFile</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLPreserveFile</command>
                <arg choice="req">
                  <replaceable>filename</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLPreserveFile offline-preserve
              </simpara>
              <simpara>Default: /tmp/sql-preserve</simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                mod_log_sql writes queries to this local preserve file
                in the event that it cannot reach the database, and thus
                ensures that your high-availability web frontend does
                not lose logs during a temporary database outage. This
                could happen for a number of reasons: the database goes
                offline, the network breaks, etc. You will not lose
                entries since the module has this backup. The file
                consists of a series of SQL statements that can be
                imported into your database at your convenience;
                furthermore, because the SQL queries contain the access
                timestamps you do not need to worry about out-of-order
                data after the import, which is done in a simple manner:
              </para>
              <programlisting format="linespecific"># mysql -uadminuser -p mydbname &lt; /tmp/sql-preserve</programlisting>
              <para>
                If you do not define LogSQLPreserveFile then all virtual
                servers will log to the same default preserve file (
                <filename>/tmp/sql-preserve</filename>
                ). You can redefine this on a virtual-host basis in
                order to segregate your preserve files if you desire.
                Note that segregation is not usually necessary, as the
                SQL statements that are written to the preserve file
                already distinguish between different virtual hosts if
                you include the 'v' character in your
                LogSQLTransferLogFormat directive. It is only necessary
                to segregate preserve-files by virualhost if you also
                segregate access logs by virtualhost.
              </para>
              <para>
                The module will log to Apache's ErrorLog when it notices
                a database outage, and upon database return. You will
                therefore know when the preserve file is being used,
                although it is your responsibility to import the file.
              </para>
              <para>
                The file does not need to be created in advance. It is
                safe to remove or rename the file without interrupting
                Apache, as the module closes the filehandle immediately
                after completing the write. The file is created with the
                user &amp; group ID of the running Apache process (e.g.
                'nobody' on many Linux distributions).
              </para>
            </listitem>
          </varlistentry>
        </variablelist>
      </section>
      <section>
        <title>Table Names</title>
        <variablelist>
          <varlistentry>
            <term>LogSQLTransferLogTable</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLTransferLogTable</command>
                <arg choice="req">
                  <replaceable>table-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLTransferLogTable access_log_table
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines which table is used for logging of Apache's
                transfers; this is analogous to Apache's TransferLog
                directive. table-name must be a valid table within the
                database defined in the LogSQLLoginInfo connection URI.
              </para>
              <para>
                This directive is
                <emphasis>not</emphasis>
                necessary if you declare LogSQLMassVirtualHosting On,
                since that directive activates dynamically-named tables.
                If you attempt to use LogSqlTransferlogTable at the same
                time a warning will be logged and it will be ignored,
                since LogSQLMassVirtualHosting takes priority.
              </para>
              <note>
                <para>
                  Requires unless LogSQLMassVirtualHosting is set to On
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLCookieLogTable</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLCookieLogTable</command>
                <arg choice="req">
                  <replaceable></replaceable>
                  table-name
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLCookieLogTable cookie_log
              </simpara>
              <simpara>Default: cookies</simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines which table is used for logging of cookies.
                Working in conjunction with LogSQLWhichCookies, you can
                log many of each request's associated cookies to a
                separate table. For meaningful data retrieval the cookie
                table is keyed to the access table by the unique request
                ID supplied by the standard Apache module mod_unique_id.
              </para>
              <note>
                <para>
                  You must create the table (see create-tables.sql,
                  included in the package), or LogSQLCreateTables must
                  be set to "on".
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLHeadersInLogTable</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLHeadersInLogTable</command>
                <arg choice="req">
                  <replaceable>table-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLHeadersInLogTable headers
              </simpara>
              <simpara>Default: headers_in</simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines which table is used for logging of inbound
                headers. Working in conjunction with
                LogSQLWhichHeadersIn, you can log many of each request's
                associated headers to a separate table. For meaningful
                data retrieval the headers table is keyed to the access
                table by the unique request ID supplied by the standard
                Apache module mod_unique_id.
              </para>
              <note>
                <para>
                  Note that you must create the table (see
                  create-tables.sql, included in the package), or
                  LogSQLCreateTables must be set to "on".
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLHeadersOutLogTable</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLHeadersOutLogTable</command>
                <arg choice="req">
                  <replaceable>table-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLHeadersOutLogTable headers
              </simpara>
              <simpara>Default: headers_out</simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines which table is used for logging of outbound
                headers. Working in conjunction with
                LogSQLWhichHeadersOut, you can log many of each
                request's associated headers to a separate table. For
                meaningful data retrieval the headers table is keyed to
                the access table by the unique request ID supplied by
                the standard Apache module mod_unique_id.
              </para>
              <note>
                <para>
                  Note that you must create the table (see
                  create-tables.sql, included in the package), or
                  LogSQLCreateTables must be set to "on".
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLNotesLogTable</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLNotesLogTable</command>
                <arg choice="req">
                  <replaceable>table-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLNotesLogTable notes-log</simpara>
              <simpara>Default: notes</simpara>
              <simpara>Context: virtual_host</simpara>
              <para>
                Defines which table is used for logging of notes.
                Working in conjunction with LogSQLWhichNotes, you can
                log many of each request's associated notes to a
                separate table. For meaningful data retrieval the notes
                table is keyed to the access table by the unique request
                ID supplied by the standard Apache module mod_unique_id.
              </para>
              <note>
                <para>
                  This table must be created (see create-tables.sql
                  included in the package), or LogSQLCreateTables must
                  be set to 'On'.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLMassVirtualHosting</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLMassVirtualHosting</command>
                <arg choice="req">flag</arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLMassVirtualHosting On</simpara>
              <simpara>Default: Off</simpara>
              <simpara>Context: main server config</simpara>
              <para>
                If you administer a site hosting many, many virtual
                hosts then this option will appeal to you. If you turn
                on LogSQLMassVirtualHosting then several things happen:
              </para>
              <itemizedlist>
                <listitem>
                  <para>
                    the on-the-fly table creation feature is activated
                    automatically
                  </para>
                </listitem>
                <listitem>
                  <para>
                    the transfer log table name is dynamically set from
                    the virtual host's name after stripping out
                    SQL-unfriendly characters (example: a virtual host
                    www.grubbybaby.com gets logged to table
                    access_www_grubbybaby_com)
                  </para>
                </listitem>
                <listitem>
                  <para>
                    which, in turn, means that each virtual host logs to
                    its own segregated table. Because there is no data
                    shared between virtual servers you can grant your
                    users access to the tables they need; they will be
                    unable to view others' data.
                  </para>
                </listitem>
              </itemizedlist>
              <para>
                This is a huge boost in convenience for sites with many
                virtual servers. Activating LogSQLMassVirtualHosting
                obviates the need to create every virtual server's table
                and provides more granular security possibilities.
              </para>
              <note>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
        </variablelist>
      </section>
      <section>
        <title>Configuring What Is logged</title>
        <variablelist>
          <varlistentry id="Conf.LogSQLTransferLogFormat">
            <term>LogSQLTransferLogFormat</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLTransferLogFormat</command>
                <arg choice="req">
                  <replaceable>format-string</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLTransferLogFormat huSUTv</simpara>
              <simpara>Default: AbHhmRSsTUuv</simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Each character in the format-string defines an attribute
                of the request that you wish to log. The default logs
                the information required to create Combined Log Format
                logs, plus several extras. Here is the full list of
                allowable keys, which sometimes resemble their Apache
                counterparts, but do not always:
              </para>
              <table>
                <title>Core LogFormat parameters</title>
                <tgroup cols="5">
                  <colspec colname="1" colnum="1" />
                  <colspec colname="2" colnum="2" />
                  <colspec colname="3" colnum="3" />
                  <colspec colname="4" colnum="4" />
                  <colspec colname="5" colnum="5" />
                  <thead>
                    <row>
                      <entry colname="1">Symbol</entry>
                      <entry colname="2">Meaning</entry>
                      <entry colname="3">DB Field</entry>
                      <entry colname="4">Data Type</entry>
                      <entry colname="5">Example</entry>
                    </row>
                  </thead>
                  <tbody>
                    <row>
                      <entry colname="1">A</entry>
                      <entry colname="2">User Agent</entry>
                      <entry colname="3">agent</entry>
                      <entry colname="4">varchar(255)</entry>
                      <entry colname="5">
                        Mozilla/4.0 (compat; MSIE 6.0; Windows)
                      </entry>
                    </row>
                    <row>
                      <entry colname="1">a</entry>
                      <entry colname="2">CGi request arguments</entry>
                      <entry colname="3">request_args</entry>
                      <entry colname="4">varchar(255)</entry>
                      <entry colname="5">
                        user=Smith&amp;cart=1231&amp;item=532
                      </entry>
                    </row>
                    <row>
                      <entry colname="1">b</entry>
                      <entry colname="2">Bytes transfered</entry>
                      <entry colname="3">bytes_sent</entry>
                      <entry colname="4">int unsigned</entry>
                      <entry colname="5">32561</entry>
                    </row>
                    <row>
                      <entry colname="1">
                        c
                        <xref linkend="Foot.LogCookie" xrefstyle="footer" />
                      </entry>
                      <entry colname="2">Text of cookie</entry>
                      <entry colname="3">cookie</entry>
                      <entry colname="4">varchar(255)</entry>
                      <entry colname="5">
                        Apache=sdyn.fooonline.net 1300102700823
                      </entry>
                    </row>
                    <row>
                      <entry>f</entry>
                      <entry>Local filename requested</entry>
                      <entry>request_file</entry>
                      <entry>varchar(255)</entry>
                      <entry>/var/www/html/books-cycroad.html</entry>
                    </row>
                    <row>
                      <entry>H</entry>
                      <entry>HTTP request_protocol</entry>
                      <entry>request_protocol</entry>
                      <entry>varchar(10)</entry>
                      <entry>HTTP/1.1</entry>
                    </row>
                    <row>
                      <entry>h</entry>
                      <entry>Name of remote host</entry>
                      <entry>remote_host</entry>
                      <entry>varchar(50)</entry>
                      <entry>blah.foobar.com</entry>
                    </row>
                    <row>
                      <entry>I</entry>
                      <entry>Request ID (from modd_unique_id)</entry>
                      <entry>id</entry>
                      <entry>char(19)</entry>
                      <entry>POlFcUBRH30AAALdBG8</entry>
                    </row>
                    <row>
                      <entry>l</entry>
                      <entry>Ident user info</entry>
                      <entry>remote_logname</entry>
                      <entry>varcgar(50)</entry>
                      <entry>bobby</entry>
                    </row>
                    <row>
                      <entry>M</entry>
                      <entry>
                        Machine ID
                        <xref linkend="Foot.MachineID" xrefstyle="footer" />
                      </entry>
                      <entry>machine_id</entry>
                      <entry>varchar(25)</entry>
                      <entry>web01</entry>
                    </row>
                    <row>
                      <entry>m</entry>
                      <entry>HTTP request method</entry>
                      <entry>request_method</entry>
                      <entry>varchar(10)</entry>
                      <entry>GET</entry>
                    </row>
                    <row>
                      <entry>P</entry>
                      <entry>httpd cchild PID</entry>
                      <entry>child_pid</entry>
                      <entry>smallint unsigned</entry>
                      <entry>3215</entry>
                    </row>
                    <row>
                      <entry>p</entry>
                      <entry>http port</entry>
                      <entry>server_port</entry>
                      <entry>smallint unsigned</entry>
                      <entry>80</entry>
                    </row>
                    <row>
                      <entry>R</entry>
                      <entry>Referer</entry>
                      <entry>referer</entry>
                      <entry>varchar(255)</entry>
                      <entry>
                        http://www.biglinks4u.com/linkpage.html
                      </entry>
                    </row>
                    <row>
                      <entry>r</entry>
                      <entry>Request in full form</entry>
                      <entry>request_line</entry>
                      <entry>varchar(255)</entry>
                      <entry>GET /books-cycroad.html HTTP/1.1</entry>
                    </row>
                    <row>
                      <entry>S</entry>
                      <entry>
                        Time of request in UNIX time_t format
                      </entry>
                      <entry>time_stamp</entry>
                      <entry>int unsigned</entry>
                      <entry>1005598029</entry>
                    </row>
                    <row>
                      <entry>s</entry>
                      <entry>HTTP Response Code Status</entry>
                      <entry>status</entry>
                      <entry>smallint</entry>
                      <entry>200</entry>
                    </row>
                    <row>
                      <entry>T</entry>
                      <entry>Seconds to service request</entry>
                      <entry>request_duration</entry>
                      <entry>smallint unsigned</entry>
                      <entry>2</entry>
                    </row>
                    <row>
                      <entry>t</entry>
                      <entry>Time of request in human format</entry>
                      <entry>request_time</entry>
                      <entry>char(28)</entry>
                      <entry>[02/Dec/2001:15:01:26 -0800]</entry>
                    </row>
                    <row>
                      <entry>U</entry>
                      <entry>Request in simple form</entry>
                      <entry>request_uri</entry>
                      <entry>varchar(255)</entry>
                      <entry>/books-cycroad.html</entry>
                    </row>
                    <row>
                      <entry>u</entry>
                      <entry>User info from HTTP auth</entry>
                      <entry>remote_user</entry>
                      <entry>varchar(50)</entry>
                      <entry>bobby</entry>
                    </row>
                    <row>
                      <entry>v</entry>
                      <entry>Virtual host servicing the request</entry>
                      <entry>virtual_host</entry>
                      <entry>varchar(255)</entry>
                      <entry>www.foobar.com</entry>
                    </row>
                    <row>
                      <entry>V</entry>
                      <entry>
                        requested Virtual host name (mass
                        virtualhosting)
                      </entry>
                      <entry>virtual_host</entry>
                      <entry>varchar(255)</entry>
                      <entry>www.foobar.org</entry>
                    </row>
                  </tbody>
                </tgroup>
              </table>
              <note>
                <simpara id="Foot.LogCookie">
                  [1] You must also specify LogSQLWhichCookie for this
                  to take effect.
                </simpara>
                <simpara id="Foot.MachineID">
                  [2] You must also specify LogSQLmachineID for this to
                  take effect.
                </simpara>
              </note>
              <table>
                <title>SSL LogFormat Parameters</title>
                <tgroup cols="5">
                  <colspec colname="1" colnum="1" />
                  <colspec colname="2" colnum="2" />
                  <colspec colname="3" colnum="3" />
                  <colspec colname="4" colnum="4" />
                  <colspec colname="5" colnum="5" />
                  <thead>
                    <row>
                      <entry colname="1">Symbol</entry>
                      <entry colname="2">Meaning</entry>
                      <entry colname="3">DB Field</entry>
                      <entry colname="4">Data Type</entry>
                      <entry colname="5">Example</entry>
                    </row>
                  </thead>
                  <tbody>
                    <row>
                      <entry colname="1">z</entry>
                      <entry colname="2">SSL cipher used</entry>
                      <entry colname="3">ssl_cipher</entry>
                      <entry colname="4">varchar(25)</entry>
                      <entry colname="5">RC4-MD5</entry>
                    </row>
                    <row>
                      <entry colname="1">q</entry>
                      <entry colname="2">
                        Keysize of the SSL connection
                      </entry>
                      <entry colname="3">ssl_keysize</entry>
                      <entry colname="4">smallint unsigned</entry>
                      <entry colname="5">56</entry>
                    </row>
                    <row>
                      <entry colname="1">Q</entry>
                      <entry colname="2">
                        maximum keysize supported
                      </entry>
                      <entry colname="3">ssl_maxkeysize</entry>
                      <entry colname="4">smallint unsigned</entry>
                      <entry colname="5">128</entry>
                    </row>
                  </tbody>
                </tgroup>
              </table>
              <table>
                <title>LogIO LogFormat Parameters</title>
                <tgroup cols="5">
                  <colspec colname="1" colnum="1" />
                  <colspec colname="2" colnum="2" />
                  <colspec colname="3" colnum="3" />
                  <colspec colname="4" colnum="4" />
                  <colspec colname="5" colnum="5" />
                  <thead>
                    <row>
                      <entry colname="1">Symbol</entry>
                      <entry colname="2">Meaning</entry>
                      <entry colname="3">DB Field</entry>
                      <entry colname="4">Data Type</entry>
                      <entry colname="5">Example</entry>
                    </row>
                  </thead>
                  <tbody>
                    <row>
                      <entry colname="1">i</entry>
                      <entry colname="2">Number of actual Bytes transfered in with the request</entry>
                      <entry colname="3">bytes_in</entry>
                      <entry colname="4">int unsigned</entry>
                      <entry colname="5">505</entry>
                    </row>
                    <row>
                      <entry colname="1">o</entry>
                      <entry colname="2">Number of actual Bytes transfered out with the request</entry>
                      <entry colname="3">bytes_out</entry>
                      <entry colname="4">int unsigned</entry>
                      <entry colname="5">4168</entry>
                    </row>
                  </tbody>
                </tgroup>
              </table>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLRemhostIgnore</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLRemhostIgnore</command>
                <arg choice="req" rep="repeat">
                  <replaceable>hostname</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLRemhostIgnore localnet.com
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Lists a series of smortrings that, if present in the
                REMOTE_HOST, will cause that request to
                <emphasis>not</emphasis>
                be logged. This directive is useful for cutting down on
                log clutter when you are certain that you want to ignore
                requests from certain hosts, such as your own internal
                network machines. See section
                <xref endterm="Sect.Ignore.title" linkend="Sect.Ignore" />
                for some tips for using this directive.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <para>
                Each string is separated by a space, and no regular
                expressions or globbing are allowed. Each string is
                evaluated as a substring of the REMOTE_HOST using
                strstr(). The comparison is case sensitive.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLRequestAccept</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLRequestAccept</command>
                <arg choice="req" rep="repeat">
                  <replaceable>substring</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLRequestAccept .html .php .jpg
              </simpara>
              <simpara>
                Default: if not specified, all requests are 'accepted'
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Lists a series of strings that, if present in the URI,
                will permit that request to be considered for logging
                (depending on additional filtering by the "ignore"
                directives). Any request that fails to match one of the
                LogSQLRequestAccept entries will be discarded.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <para>
                This directive is useful for cutting down on log clutter
                when you are certain that you only want to log certain
                kinds of requests, and just blanket-ignore everything
                else. See section
                <xref endterm="Sect.Ignore.title" linkend="Sect.Ignore" />
                for some tips for using this directive.
              </para>
              <para>
                Each string is separated by a space, and no regular
                expressions or globbing are allowed. Each string is
                evaluated as a substring of the URI using strstr(). The
                comparison is case sensitive.
              </para>
              <para>
                This directive is completely optional. It is more
                general than LogSQLRequestIgnore and is evaluated before
                LogSQLRequestIgnore . If this directive is not used,
                <emphasis>all</emphasis>
                requests are accepted and passed on to the other
                filtering directives. Therefore, only use this directive
                if you have a specific reason to do so.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLRequestIgnore</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLRequestIgnore</command>
                <arg choice="req" rep="repeat">
                  <replaceable>substring</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLRequestIgnore root.exe cmd.exe
                default.ida favicon.ico
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Lists a series of strings that, if present in the URI,
                will cause that request to
                <emphasis>NOT</emphasis>
                be logged. This directive is useful for cutting down on
                log clutter when you are certain that you want to ignore
                requests for certain objects. See section
                <xref endterm="Sect.Ignore.title" linkend="Sect.Ignore" />
                for some tips for using this directive.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <para>
                Each string is separated by a space, and no regular
                expressions or globbing are allowed. Each string is
                evaluated as a substring of the URI using strstr(). The
                comparison is case sensitive.
              </para>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLWhichCookie</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLWhichCookie</command>
                <arg choice="req">
                  <replaceable>cookiename</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>Example; LogSQLWhichCookie Clicks</simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                In HTTP, cookies have names to distinguish them from
                each other. Using mod_usertrack, for example, you can
                give your user-tracking cookies a name with the
                CookieName directive.
              </para>
              <para>
                mod_log_sql allows you to log cookie information.
                LogSQL_WhichCookie tells mod_log_sql which cookie to
                log. This is necessary because you will usually be
                setting and receiving more than one cookie from a
                client.
              </para>
              <note>
                <para>
                  You must include a 'c' character in
                  LogSQLTransferLogFormat for this directive to take
                  effect.
                </para>
                <para>
                  although this was origintally intended for people
                  using mod_usertrack to create user-tracking cookies,
                  you are not restricted in any way. You can choose
                  which cookie you wish to log to the database - any
                  cookie at all - and it does not necessarily have to
                  have anything to do with mod_usertrack.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLWhichCookies</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLWhichCookies</command>
                <arg choice="req" rep="repeat">
                  <replaceable>cookie-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: logSQLWhichCookies userlogin cookie1 cookie2
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines the list of cookies you would like logged. This
                works in conjunction with LogSQLCookieLogTable. This
                directive does
                <emphasis>not</emphasis>
                require any additional characters to be added to the
                LogSQLTransferLogFormat string. The feature is activated
                simply by including this directive, upon which you will
                begin populating the separate cookie table with data.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <note>
                <para>
                  The table must be created (see create-tables.sql,
                  included in the package), or LogSQLCreateTables must
                  be set to 'On'.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLWhichHeadersIn</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLWhichHeadersIn</command>
                <arg choice="req" rep="repeat">
                  <replaceable>header-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLWhichHeadersIn User-Agent Accept-Encoding
                Host
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines the list of inbound headers you would like
                logged. This works in conjunction with
                LogSQLHeadersInLogTable. This directive does not require
                any additional characters to be added to the
                LogSQLTransferLogFormat string. The feature is activated
                simply by including this directive, upon which you will
                begin populating the separate inbound-headers table with
                data.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <note>
                <para>
                  The table must be created (see create-tables.sql,
                  included in the package), or LogSQLCreateTables must
                  be set to 'On'.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLWhichHeadersOut</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLWhichHeadersOut</command>
                <arg choice="req" rep="repeat">
                  <replaceable>header-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLWhichHeadersOut Expires Content-Type
                Cache-Control
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines the list of outbound headers you would like
                logged. This works in conjunction with
                LogSQLHeadersOutLogTable. This directive does not
                require any additional characters to be added to the
                LogSQLTransferLogFormat string. The feature is activated
                simply by including this directive, upon which you will
                begin populating the separate outbound-headers table
                with data.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <note>
                <para>
                  The table must be created (see create-tables.sql,
                  included in the package), or LogSQLCreateTables must
                  be set to 'On'.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLWhichNotes</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLWhichNotes</command>
                <arg choice="req" rep="repeat">
                  <replaceable>note-name</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLWhichNotes mod_gzip_result
                mod_gzip_ompression_ratio
              </simpara>
              <simpara>Context: virtual host</simpara>
              <para>
                Defines the list of notes you would like logged. This
                works in conjunction with LogSQLNotesLogTable. This
                directive does not require any additional characters to
                be added to the LogSQLTransferLogFormat string. The
                feature is activated simply by including this directive,
                upon which you will begin populating the separate notes
                table with data.
              </para>
              <para>
                Each string may contain a + or - prefix in a
                &lt;VirtualHost&gt; context and will cause those strings
                to be added (+) or removed (-) from the global
                configuration. Otherwise the global is completely
                ignored and overridden if defined in a
                &lt;VirtualHost&gt;
              </para>
              <note>
                <para>
                  The table must be created (see create-tables.sql,
                  included in the package), or LogSQLCreateTables must
                  be set to 'On'.
                </para>
              </note>
            </listitem>
          </varlistentry>
        </variablelist>
      </section>
      <section>
        <title>Deprecated Commands</title>
        <variablelist>
          <varlistentry>
            <term>LogSQLSocketFile [Deprecated]</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLSocketFile</command>
                <arg choice="req">
                  <replaceable>filename</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>
                Example: LogSQLSocketFile /tmp/mysql.sock
              </simpara>
              <simpara>Default: (database specific)</simpara>
              <simpara>
                Default (MySQL): /var/lib/mysql/mysql.sock
              </simpara>
              <simpara>Context: main server config</simpara>
              <para>
                At Apache runtime you can specify the MySQL socket file
                to use. Set this once in your main server config to
                override the default value. This value is irrelevant if
                your database resides on a separate machine.
              </para>
              <para>
                mod_log_sql will automatically employ the socket for db
                communications if the database resides on the local
                host. If the db resides on a separate host the module
                will automatically use TCP/IP. This is a function of the
                MySQL API and is not user-configurable.
              </para>
              <note>
                <para>
                  This directive is deprecated in favor of LogSQLDBParam
                  socketfile [socketfilename]
                </para>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLTCPPort [Deprecated]</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLTCPPort</command>
                <arg choice="req">
                  <replaceable>port-number</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLTCPPort 3309</simpara>
              <simpara>Default: (database specific)</simpara>
              <simpara>Default (MySQL): 3306</simpara>
              <simpara>Context: main server config</simpara>
              <para>
                Your database may listen on a different port than the
                default. If so, use this directive to instruct the
                module which port to use. This directive only applies if
                the database is on a different machine connected via
                TCP/IP.
              </para>
              <note>
                <para>
                  This directive is deprecated in favor of LogSQLDBParam
                  tcpport [port-number]
                </para>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term>LogSQLDatabase [Deprecated]</term>
            <listitem>
              <cmdsynopsis sepchar=" ">
                <command>LogSQLDatabase</command>
                <arg choice="req">
                  <replaceable>database</replaceable>
                </arg>
              </cmdsynopsis>
              <simpara>Example: LogSQLDatabase loggingdb</simpara>
              <simpara>Context: main server config</simpara>
              <para>
                Defines the database that is used for logging.
                "database" must be a valid db on the MySQL host defined
                in LogSQLLoginInfo
              </para>
              <note>
                <para>
                  This directive is deprecated in favor of the URI form
                  of LogSQLLoginInfo.
                </para>
                <para>
                  This is defined only once in the
                  <filename>httpd.conf</filename>
                  file.
                </para>
              </note>
            </listitem>
          </varlistentry>
        </variablelist>
      </section>
    </section>
  </section>
  <section id="Sect.FAQ">
    <title>FAQ</title>
    <qandaset>
      <qandadiv>
        <title>General module questions</title>
        <qandaentry id="FAQ.WhyLogToSQL">
          <question>
            <para>Why log to an SQL database?</para>
          </question>
          <answer>
            <para>
              To begin with, let's get it out of the way: logging to a
              database is not a panacea. But while there are
              complexities with this solution, the benefit can be
              substantial for certain classes of administrator or people
              with advanced requirements:
            </para>
            <itemizedlist>
              <listitem>
                <para>
                  Chores like log rotation go away, as you can DELETE
                  records from the SQL database once they are no longer
                  useful. For example, the excellent and popular
                  log-analysis tool Webalizer (http://www.webalizer.com)
                  does not need historic logs after it has processed
                  them, enabling you to delete older logs.
                </para>
              </listitem>
              <listitem>
                <para>
                  People with clusters of web servers (for high
                  availability) will benefit the most - all their
                  webservers can log to a single SQL database. This
                  obviates the need to collate/interleave the many
                  separate logfiles, which can be / highly/ problematic.
                </para>
              </listitem>
              <listitem>
                <para>
                  People acquainted with the power of SQL SELECT
                  statements will know the flexibility of the extraction
                  possibilities at their fingertips.
                </para>
              </listitem>
            </itemizedlist>
            <para>
              For example, do you want to see all your 404's? Do this:
            </para>
            <programlisting>SELECT remote_host, status, request_uri, bytes_sent, from_unixtime(time_stamp)
FROM acc_log_tbl WHERE status=404 ORDER BY time_stamp;</programlisting>
            <table>
              <title></title>
              <tgroup cols="5">
                <colspec colname="1" />
                <colspec colname="2" />
                <colspec colname="3" />
                <colspec colname="4" />
                <colspec colname="5" />
                <thead>
                  <row>
                    <entry colname="1">remote_host</entry>
                    <entry colname="2">status</entry>
                    <entry colname="3">request_uri</entry>
                    <entry colname="4">bytes_sent</entry>
                    <entry colname="5">from_unixtime(time_stamp)</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry colname="1">marge.mmm.co.uk</entry>
                    <entry colname="2">404</entry>
                    <entry colname="3">/favicon.ico</entry>
                    <entry colname="4">321</entry>
                    <entry colname="5">2001-11-20 02:30:56</entry>
                  </row>
                  <row>
                    <entry colname="1">62.180.239.251</entry>
                    <entry colname="2">404</entry>
                    <entry colname="3">/favicon.ico</entry>
                    <entry colname="4">333</entry>
                    <entry colname="5">2001-11-20 02:45:25</entry>
                  </row>
                  <row>
                    <entry colname="1">212.234.12.66</entry>
                    <entry colname="2">404</entry>
                    <entry colname="3">/favicon.ico</entry>
                    <entry colname="4">321</entry>
                    <entry colname="5">2001-11-20 03:01:00</entry>
                  </row>
                  <row>
                    <entry colname="1">212.210.78.254</entry>
                    <entry colname="2">404</entry>
                    <entry colname="3">/favicon.ico</entry>
                    <entry colname="4">333</entry>
                    <entry colname="5">2001-11-20 03:26:05</entry>
                  </row>
                </tbody>
              </tgroup>
            </table>
            <para>
              Or do you want to see how many bytes you've sent within a
              certain directory or site? Do this:
            </para>
            <programlisting>SELECT request_uri,sum(bytes_sent) AS bytes, count(request_uri) AS howmany
FROM acc_log_tbl
WHERE request_uri LIKE '%mod_log_sql%'
GROUP BY request_uri ORDER BY howmany DESC;</programlisting>
            <table>
              <title></title>
              <tgroup cols="3">
                <colspec colname="1" />
                <colspec colname="2" />
                <colspec colname="3" />
                <thead>
                  <row>
                    <entry colname="1">request_uri</entry>
                    <entry colname="2">bytes</entry>
                    <entry colname="3">howmany</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry colname="1">/mod_log_sql/style_1.css</entry>
                    <entry colname="2">157396</entry>
                    <entry colname="3">1288</entry>
                  </row>
                  <row>
                    <entry colname="1">/mod_log_sql/</entry>
                    <entry colname="2">2514337</entry>
                    <entry colname="3">801</entry>
                  </row>
                  <row>
                    <entry colname="1">
                      /mod_log_sql/mod_log_sql.tar.gz
                    </entry>
                    <entry colname="2">9769312</entry>
                    <entry colname="3">456</entry>
                  </row>
                  <row>
                    <entry colname="1">/mod_log_sql/faq.html</entry>
                    <entry colname="2">5038728</entry>
                    <entry colname="3">436</entry>
                  </row>
                </tbody>
              </tgroup>
            </table>
            <para>
              Or maybe you want to see who's linking to you? Do this:
            </para>
            <programlisting>SELECT count(referer) AS num,referer
FROM acc_log_tbl
WHERE request_uri='/mod_log_sql/'
GROUP BY referer ORDER BY num DESC;</programlisting>
            <table>
              <title></title>
              <tgroup cols="2">
                <colspec colname="1" />
                <colspec colname="2" />
                <thead>
                  <row>
                    <entry colname="1">num</entry>
                    <entry colname="2">referer</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry colname="1">271</entry>
                    <entry colname="2">
                      http://freshmeat.net/projects/mod_log_sql/
                    </entry>
                  </row>
                  <row>
                    <entry colname="1">96</entry>
                    <entry colname="2">
                      http://modules.apache.org/search?id=339
                    </entry>
                  </row>
                  <row>
                    <entry colname="1">48</entry>
                    <entry colname="2">http://freshmeat.net/</entry>
                  </row>
                  <row>
                    <entry colname="1">8</entry>
                    <entry colname="2">http://freshmeat.net</entry>
                  </row>
                </tbody>
              </tgroup>
            </table>
            <para>
              As you can see, there are myriad possibilities that can be
              constructed with the wonderful SQL SELECT statement.
              Logging to an SQL database can be really quite useful!
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>Why use MySQL? Are there alternatives?</para>
          </question>
          <answer>
            <para>
              MySQL is a robust, free, and very powerful
              production-quality database engine. It is well supported
              and comes with detailed documentation. Many 3rd-party
              software pacakges (e.g. Slashcode, the engine that powers
              Slashdot) run exclusively with MySQL. In other words, you
              will belong to a very robust and well-supported community
              by choosing MySQL.
            </para>
            <para>
              That being said, there are alternatives. PostgreSQL is
              probably MySQL's leading "competitor" in the free database
              world. There is also an excellent module available for
              Apache to permit logging to a PostgreSQL database, called
              <ulink url="http://www.digitalstratum.com/pglogd/">
                pgLOGd
              </ulink>
            </para>
          </answer>
          <answer>
            <note>
              <para>
                Currently a database abstraction system is in the works
                to allow any database to be used with mod_log_sql.
              </para>
            </note>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>Is this code production-ready?</para>
          </question>
          <answer>
            <para>
              By all accounts it is. It is known to work without a
              problem on many-thousands-of-hits-per-day webservers. Does
              that mean it is 100% bug free? Well, no software is, but
              it is well-tested and believed to be fully compatible with
              production environments. (The usual disclaimers apply.
              This software is provided without warranty of any kind.)
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>Who's using mod_log_sql?</para>
          </question>
          <answer>
            <para>
              Good question! It would be great to find out! If you are a
              production-level mod_log_sql user, please contact eddie at
              &EmailContact;
              so that you can be mentioned here.
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              Why doesn't the module also replace the Apache ErrorLog?
            </para>
          </question>
          <answer>
            <para>
              There are circumstances when that would be quite unwise --
              for example, if Apache could not reach the MySQL server
              for some reason and needed to log that fact. Without a
              text-based error log you'd never know anything was wrong,
              because Apache would be trying to log a database
              connection error to the database... you get the point.
            </para>
          </answer>
          <answer>
            <para>
              Error logs are usually not very high-traffic and are
              really best left as text files on a web server machine.
            </para>
          </answer>
          <answer>
            <para>
              The Error log is free format text.. (no specified
              formatting what, so ever) which is rather difficult to
              nicely format for storing in a database.
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>Does mod_log_sql work with Apache 2.x?</para>
          </question>
          <answer>
            <para>
              Yes. A port of mod_log_sql is available for Apache 2.x as
              of mod_log_sql 1.90
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              Does mod_log_sql connect to MySQL via TCP/IP or a socket?
            </para>
          </question>
          <answer>
            <para>Quick answer, Yes.</para>
          </answer>
          <answer>
            <para>
              It depends! This is not determined by mod_log_sql.
              mod_log_sql relies on a connection command that is
              supplied in the MySQL API, and that command is somewhat
              intelligent. How it works:
            </para>
            <itemizedlist>
              <listitem>
                <simpara>
                  if the specified MySQL database is on the same
                  machine, the connection command uses a socket to
                  communicate with MySQL
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  if the specified MySQL database is on a different
                  machine, mod_log_sql connects using TCP/IP.
                </simpara>
              </listitem>
            </itemizedlist>
            <para>
              You don't have any control of which methodology is used.
              You can fine-tune some of the configuration, however. The
              LogSQLSocketFile runtime configuration directive overrides
              the default of "/var/lib/mysql/mysql.sock" for
              socket-based connections, whereas the LogSQLTCPPort
              command allows to you override the default TCP port of
              3306 for TCP/IP connections.
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>I have discovered a bug. Who can I contact?</para>
          </question>
          <answer>
            <para>
              Please contact Edward Rudd at
              &EmailContact;
              , or post a message to the mod_log_sql
              <xref endterm="Sect.MailingLists.title"
                linkend="Sect.MailingLists" />
              . Your comments, suggestions, bugfixes, bug catches, and
              usage testimonials are always welcome. As free software,
              mod_log_sql is intended to be a community effort -- any
              code contributions or other ideas will be fully and openly
              credited, of course.
            </para>
          </answer>
        </qandaentry>
      </qandadiv>
      <qandadiv>
        <title>Problems</title>
        <qandaentry>
          <question>
            <para>
              Apache segfaults or has other problems when using PHP and
              mod_log_sql
            </para>
          </question>
          <answer>
            <para>
              This occurs if you compiled PHP with MySQL database
              support. PHP utilizes its internal, bundled MySQL
              libraries by default. These conflict with the "real" MySQL
              libraries linked by mod_log_sql, causing the segmentation
              fault.
            </para>
            <para>
              PHP and mod_log_sql can be configured to happily coexist.
              The solution is to configure PHP to link against the real
              MySQL libraries: recompile PHP using
              --with-mysql=/your/path. Apache will run properly once the
              modules are all using the same version of the MySQL
              libraries.
            </para>
          </answer>
        </qandaentry>
        <qandaentry id="FAQ.NothingLogged">
          <question>
            <para>
              Apache appears to start up fine, but nothing is getting
              logged in the database
            </para>
          </question>
          <answer>
            <para>
              If you do not see any entries in the access_log, then
              something is preventing the inserts from happening. This
              could be caused by several things:
            </para>
            <itemizedlist>
              <listitem>
                <simpara>
                  Improper privileges set up in the MySQL database
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  You are not hitting a VirtualHost that has a
                  LogSQLTransferLogTable entry
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  You did not specify the right database host or login
                  information
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  Another factor is preventing a connection to the
                  database
                </simpara>
              </listitem>
            </itemizedlist>
            <note>
              <para>
                It is improper to ask for help before you have followed
                these steps.
              </para>
            </note>
            <para>
              First examine the MySQL log that you established in step
              <xref linkend="Item.EnableLogging" />
              of section
              <xref endterm="Sect.Preperation.title"
                linkend="Sect.Preperation" />
              . Ensure that the INSERT statements are not being rejected
              because of a malformed table name or other typographical
              error. By enabling that log, you instructed MySQL to log
              every connection and command it receives -- if you see no
              INSERT attempts in the log, the module isn't successfully
              connecting to the database. If you see nothing at all in
              the log -- not even a record of your administrative
              connection attempts, then you did not enable the log
              correctly. If you do see INSERT attempts but they are
              failing, the log should tell you why.
            </para>
            <para>
              Second, confirm that your LogSQL* directives are all
              correct.
            </para>
            <para>
              Third, examine the Apache error logs for messages from
              mod_log_sql; the module will offer hints as to why it
              cannot connect, etc.
            </para>
            <para>
              The next thing to do is to change the LogLevel directive
              <emphasis>
                in the main server config as well as in each VirtualHost
                config:
              </emphasis>
            </para>
            <programlisting>LogLevel debug
ErrorLog /var/log/httpd/server-messages</programlisting>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              Why do I get the message "insufficient configuration info
              to establish database link" in my Apache error log?
            </para>
          </question>
          <answer>
            <para>
              At a minimum, LogSQLLoginInfo in the URl form and either
              LogSQLTableName or LogSQLMassVirtualHosting must be
              defined in order for the module to be able to establish a
              database link. If these are not defined or are incomplete
              you will receive this error message.
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              My database cannot handle all the open connections from
              mod_log_sql, is there anything I can do?
            </para>
          </question>
          <answer>
            <para>
              The rule of thumb: if you have n webservers each
              configured to support y MaxClients, then your database
              must be able to handle n times y simultaneous connections
              in the worst case. Certainly you must use common sense,
              consider reasonable traffic expectations and structure
              things accordingly.
            </para>
          </answer>
          <answer>
            <para>
              Tweaking my.cnf to scale to high connection loads is
              imperative. But if hardware limitations prevent your MySQL
              server from gracefully handling the number of incoming
              connections, it would be beneficial to upgrade the memory
              or CPU on that server in order to handle the load.
            </para>
          </answer>
          <answer>
            <para>
              Jeremy Zawodny, a highly respected MySQL user and
              contributor to Linux Magazine, has this very helpful and
              highly appropriate article on tuning MySQL:
              <ulink
                url="http://jeremy.zawodny.com/blog/archives/000173.html">
                MySQL, Linux, and Thread Caching
              </ulink>
            </para>
          </answer>
          <answer>
            <para>
              Please remember that mod_log_sql's overriding principle is
              performance -- that is what the target audience demands
              and expects. Other database logging solutions do not open
              and maintain many database connections, but their
              performance suffers drastically. For example, pgLOGd
              funnels all log connections through a separate daemon that
              connects to the database, but that bottlenecks the entire
              process. mod_log_sql achieves performance numbers an order
              of magnitude greater than the alternatives because it
              dispenses with the overhead associated with rapid
              connection cycling, and it does not attempt to shoehorn
              all the database traffic through a single extra daemon or
              proxy process.
            </para>
          </answer>
          <answer>
            <note>
              <para>
                Currently connection pooling is being implemented as
                part of the Database Abstraction layer to allow multiple
                httpd processes to share connections.
              </para>
            </note>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              Why do I occasionally see a "lost connection to MySQL
              server" message in my Apache error log?
            </para>
          </question>
          <answer>
            <para>
              This message may appear every now and then in your Apache
              error log, especially on very lightly loaded servers. This
              does not mean that anything is necessarily wrong. Within
              each httpd child process, mod_log_sql will open (and keep
              open) a connection to the MySQL server. MySQL, however,
              will close connections that have not been used in a while;
              the default timeout is 8 hours. When this occurs,
              mod_log_sql will notice and re-open the connection. That
              event is what is being logged, and looks like this:
            </para>
            <programlisting>[Tue Nov 12 19:04:10 2002] [error] mod_log_sql: first attempt failed,
  API said: error 2013, Lost connection to MySQL server during query
[Tue Nov 12 19:04:10 2002] [error] mod_log_sql: reconnect successful
[Tue Nov 12 19:04:10 2002] [error] mod_log_sql: second attempt successful</programlisting>
            <para>
              Reference:
              <ulink
                url="http://dev.mysql.com/doc/mysql/en/Gone_away.html">
                MySQL documentation
              </ulink>
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              Sometimes a single VirtualHost gets logged to two
              different tables (e.g. access_foo_com,
              access_www_foo_com). Or, accesses to an unqualified
              hostname (e.g. "http://intranet/index.html") get logged in
              separate tables.
            </para>
          </question>
          <answer>
            <para>
              Proper usage of the Apache runtime ServerName directive
              and the directive UseCanonicalName On (or DNS) are
              necessary to prevent this problem. "On" is the default for
              UseCanonicalName, and specifies that self-referential URLs
              are generated from the ServerName part of your
              VirtualHost:
            </para>
            <para>
              With UseCanonicalName on (and in all versions prior to
              1.3) Apache will use the ServerName and Port directives to
              construct the canonical name for the server. With
              UseCanonicalName off Apache will form self-referential
              URLs using the hostname and port supplied by the client if
              any are supplied (otherwise it will use the canonical
              name, as defined above). [From
              <ulink
                url="http://httpd.apache.org/docs/mod/core.html#usecanonicalname">
                the Apache documentation
              </ulink>
              ]
            </para>
            <para>
              The module inherits Apache's "knowledge" about the server
              name being accessed. As long as those two directives are
              properly configured, mod_log_sql will log to only one
              table per virtual host while using
              LogSQLMassVirtualHosting.
            </para>
          </answer>
        </qandaentry>
      </qandadiv>
      <qandadiv>
        <title>Performance and Tuning</title>
        <qandaentry>
          <question>
            <para>How well does it perform?</para>
          </question>
          <answer>
            <para>
              mod_log_sql scales to very high loads. Apache 1.3.22 +
              mod_log_sql was benchmarked using the "ab" (Apache Bench)
              program that comes with the Apache distribution; here are
              the results.
            </para>
            <itemizedlist>
              <title>Overall configuration</title>
              <listitem>
                <simpara>Machine A: Apache webserver</simpara>
              </listitem>
              <listitem>
                <simpara>Machine B: MySQL server</simpara>
              </listitem>
              <listitem>
                <simpara>
                  Machines A and B connected with 100Mbps Ethernet
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  Webserver: Celeron 400, 128MB RAM, IDE storage
                </simpara>
              </listitem>
            </itemizedlist>
            <example>
              <title>Apache configuration</title>
              <programlisting>Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 15
MinSpareServers 5
StartServers 10
MaxSpareServers 15
MaxClients 256
MaxRequestsPerChild 5000
LogSQLTransferLogFormat AbHhmRSsTUuvc
LogSQLWhichCookie Clicks
CookieTracking on
CookieName Clicks</programlisting>
            </example>
            <example>
              <title>"ab" commandline</title>
              <programlisting>./ab -c 10 -t 20 -v 2 -C Clicks=ab_run http://www.hostname.com/target</programlisting>
            </example>
            <para>
              ( 10 concurrent requests; 20 second test; setting a cookie
              "Clicks=ab_run"; target = the mod_log_sql homepage. )
            </para>
            <para>
              Ten total ab runs were conducted: five with MySQL logging
              enabled, and five with all MySQL directives commented out
              of httpd.conf. Then each five were averaged. The results:
            </para>
            <itemizedlist>
              <listitem>
                <simpara>
                  Average of five runs employing MySQL and standard text
                  logging:
                  <emphasis>
                    139.01 requests per second, zero errors.
                  </emphasis>
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  Average of five runs employing only standard text
                  logging:
                  <emphasis>
                    139.96 requests per second, zero errors.
                  </emphasis>
                </simpara>
              </listitem>
            </itemizedlist>
            <para>
              In other words, any rate-limiting effects on this
              particular hardware setup are not caused by MySQL. Note
              that although this very simple webserver setup is hardly
              cutting-edge -- it is, after all, a fairly small machine
              -- 139 requests per second equal over twelve million hits
              per day.
            </para>
            <orderedlist>
              <title>
                If you run this benchmark yourself, take note of three
                things:
              </title>
              <listitem>
                <simpara>
                  Use a target URL that is on your own webserver :-).
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  Wait until all your connections are closed out between
                  runs; after several thousand requests your TCP/IP
                  stack will be filled with hundreds of connections in
                  TIME_WAIT that need to close. Do a "netstat -t|wc -l"
                  on the webserver to see. If you don't wait, you can
                  expect to see a lot of messages like "ip_conntrack:
                  table full, dropping packet" in your logs. (This has
                  nothing to do with mod_log_sql, this is simply the
                  nature of the TCP/IP stack in the Linux kernel.)
                </simpara>
              </listitem>
              <listitem>
                <simpara>
                  When done with your runs, clean these many thousands
                  of requests out of your database:
                </simpara>
                <programlisting>mysql&gt; delete from access_log where agent like 'ApacheBench%';
mysql&gt; optimize table access_log;</programlisting>
              </listitem>
            </orderedlist>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              Do I need to be worried about all the running MySQL
              children? Will holding open n Apache-to-MySQL connections
              consume a lot of memory?
            </para>
          </question>
          <answer>
            <para>Short answer: you shouldn't be worried.</para>
          </answer>
          <answer>
            <para>
              Long answer: you might be evaluating at the output of "ps
              -aufxw" and becoming alarmed at all the 7MB httpd
              processes or 22MB mysqld children that you see. Don't be
              alarmed. It's true that mod_log_sql opens and holds open
              many MySQL connections: each httpd child maintains one
              open database connection (and holds it open for
              performance reasons). Four webservers, each running 20
              Apache children, will hold open 80 MySQL connections,
              which means that your MySQL server needs to handle 80
              simultaneous connections. In truth, your MySQL server
              needs to handle far more than that if traffic to your
              website spikes and the Apache webservers spawn off an
              additional 30 children each...
            </para>
            <para>
              Fortunately the cost reported by 'ps -aufxw' is deceptive.
              This is due to an OS memory-management feature called
              "copy-on-write." When you have a number of identical child
              processes (e.g. Apache, MySQL), it would appear in "ps" as
              though each one occupies a great deal of RAM -- as much as
              7MB per httpd child! In actuality each additional child
              only occupies a small bit of extra memory -- most of the
              memory pages are common to each child and therefore shared
              in a "read-only" fashion. The OS can get away with this
              because the majority of memory pages for one child are
              identical across all children. Instead of thinking of each
              child as a rubber stamp of the others, think of each child
              as a basket of links to a common memory area.
            </para>
            <para>
              A memory page is only duplicated when it needs to be
              written to, hence "copy-on-write." The result is
              efficiency and decreased memory consumption. "ps" may
              report 7MB per child, but it might really only "cost" 900K
              of extra memory to add one more child. It is not correct
              to assume that 20 Apache children with a VSZ of 7MB each
              equals (2 x 7MB) of memory consumption -- the real answer
              is much, much lower. The same "copy-on-write" rules apply
              to all your MySQL children: 40 mysqld children @ 22MB each
              do not occupy 880MB of RAM.
            </para>
            <para>
              The bottom line: although there is a cost to spawn extra
              httpd or mysqld children, that cost is not as great as
              "ps" would lead you to believe.
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              My webserver cannot handle all the traffic that my site
              receives, is there anything I can do?
            </para>
          </question>
          <answer>
            <para>
              If you have exhausted all the tuning possibilities on your
              existing server, it is probably time you evaluated the
              benefits of clustering two or more webservers together in
              a load-balanced fashion. In fact, users of such a setup
              are mod_log_sql's target audience!
            </para>
          </answer>
        </qandaentry>
        <qandaentry id="FAQ.DelayedInsert">
          <question>
            <para>
              What is the issue with activating delayed inserts?
            </para>
          </question>
          <answer>
            <para>
              INSERT DELAYED is a specific syntax to MySQL and is not
              supported by any other database. Ergo, why is it needed,
              and what MySQL deficiency is it working around? INSERT
              DELAYED is a kluge.
            </para>
          </answer>
          <answer>
            <para>
              The MySQL documentation is unclear whether INSERT DELAYED
              is even necessary for an optimized database. It says, "The
              DELAYED option for the INSERT statement is a
              MySQL-specific option that is very useful if you have
              clients that can't wait for the INSERT to complete." But
              then it goes on to say, "Note that as MyISAM tables
              supports concurrent SELECT and INSERT, if there is no free
              blocks in the middle of the data file, you very seldom
              need to use INSERT DELAYED with MyISAM."
            </para>
          </answer>
          <answer>
            <para>
              Because INSERT DELAYED returns without waiting for the
              data to be written, a hard kill of your MySQL database at
              the right (wrong?) moment could lose those logfile
              entries.
            </para>
          </answer>
          <answer>
            <para>
              As of MySQL version 3.23.52, the error return functions
              disagree after a failed INSERT DELAYED: mysql_errno()
              always returns 0, even if mysql_error() returns a textual
              error. I have reported this bug to the MySQL folks.
              However, we have no way of knowing what solution they will
              adopt to fix this, and with the worst case solution
              mod_log_sql would not be able to tell if anything went
              wrong with a delayed insert.
            </para>
          </answer>
          <answer>
            <para>
              Instead of delayed inserts, you may wish to utilize InnoDB
              tables (instead of the standard MyISAM tables). InnoDB
              tables suppot row-level locking and are recommended for
              high-volume databases.
            </para>
          </answer>
          <answer>
            <para>
              If after understanding these problems you still wish to
              enable delayed inserts, section
              <xref endterm="Sect.DelayedInsert.title"
                linkend="Sect.DelayedInsert" />
              discusses how.
            </para>
          </answer>
        </qandaentry>
      </qandadiv>
      <qandadiv>
        <title>"How do I...?" -- accomplishing certain tasks</title>
        <qandaentry>
          <question>
            <para>
              How do I extract the data in a format that my analysis
              tool can understand?
            </para>
          </question>
          <answer>
            <para>
              mod_log_sql would be virtually useless if there weren't a
              way for you to extract the data from your database in a
              somewhat meaningful fashion. To that end there's a Perl
              script enclosed with the distribution. That script
              (make_combined_log.pl) is designed to extract N-many days
              worth of access logs and provide them in a Combined Log
              Format output. You can use this very tool right in
              /etc/crontab to extract logs on a regular basis so that
              your favorite web analysis tool can read them. Or you can
              examine the Perl code to construct your own custom tool.
            </para>
            <para>
              For example, let's say that you want your web statistics
              updated once per day in the wee hours of the morning. A
              good way to accomplish that could be the following entries
              in /etc/crontab:
            </para>
            <programlisting># Generate the temporary apache logs from the MySQL database (for webalizer)
05 04 * * * root make_combined_log.pl 1 www.grubbybaby.com &gt; /var/log/temp01
# Run webalizer on httpd log
30 04 * * * root webalizer -c /etc/webalizer.conf; rm -f /var/log/temp01</programlisting>
            <para>
              Or if you have a newer system that puts files in
              /etc/cron.daily etc., create a file called "webalizer" in
              the cron.daily subdirectory. Use the following as the
              contents of your file, and make sure to chmod 755 it when
              done.
            </para>
            <programlisting>#!/bin/sh
/usr/local/sbin/make_combined_log.pl 1 www.yourdomain.com &gt; /var/log/httpd/templog
/usr/local/bin/webalizer -q -c /etc/webalizer.conf
rm -f /var/log/httpd/templog</programlisting>
            <para>See? Easy.</para>
          </answer>
        </qandaentry>
        <qandaentry id="FAQ.Cookie">
          <question>
            <para>How can I log mod_usertrack cookies?</para>
          </question>
          <answer>
            <para>
              A number of people like to log mod_usertrack cookies in
              their Apache TransferLog to aid in understanding their
              visitors' clickstreams. This is accomplished, for example,
              with a statement as follows:
            </para>
            <programlisting>LogFormat "%h %l %u %t \"%r\" %s %b \"%{Referer}i\" \"%{User-Agent}i\"" \"%{cookie}n\""</programlisting>
            <para>
              Naturally it would be nice for mod_log_sql to permit the
              admin to log the cookie data as well, so as of version
              1.10 you can do this. You need to have already compiled
              mod_usertrack into httpd -- it's one of the standard
              Apache modules.
            </para>
            <para>
              First make sure you have a column called "cookie" in the
              MySQL database to hold the cookies, which can be done as
              follows if you already have a working database:
            </para>
            <programlisting>mysql&gt; alter table acc_log_tbl add column cookie varchar(255);</programlisting>
            <para>
              Next configure your server to set usertracking cookies as
              follows, and make sure you include the new 'c' directive
              in your LogSQLTransferLogFormat, which activates cookie
              logging. Here's an example:
            </para>
            <programlisting>&lt;VirtualHost 1.2.3.4&gt;
 CookieTracking on
 CookieStyle Cookie
 CookieName Foobar
 LogSQLTransferLogFormat huSUsbTvRAc
 LogSQLWhichCookie Foobar
&lt;/VirtualHost&gt;</programlisting>
            <para>
              The first three lines configure mod_usertrack to create a
              COOKIE (RFC 2109) format cookie called Foobar. The last
              two lines tell mod_log_sql to log cookies named Foobar.
              You have to choose which cookie to log because more than
              one cookie can/will be sent to the server by the client.
            </para>
            <para>
              Recap: the 'c' character activates cookie logging, and the
              LogSQLWhichCookie directive chooses which cookie to log.
            </para>
            <para>
              FYI, you are advised NOT to use CookieStyle Cookie2 -- it
              seems that even newer browsers (IE 5.5, etc.) have trouble
              with the new COOKIE2 (RFC 2965) format. Just stick with
              the standard COOKIE format and you'll be fine.
            </para>
            <para>
              Perform some hits on your server and run a select
            </para>
            <programlisting>SELECT request_uri,cookie
FROM access_log
WHERE cookie IS NOT NULL;</programlisting>
            <table>
              <title></title>
              <tgroup cols="2">
                <colspec colname="1" />
                <colspec colname="2" />
                <thead>
                  <row>
                    <entry colname="1">request_uri</entry>
                    <entry colname="2">cookie</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry colname="1">/mod_log_sql/</entry>
                    <entry colname="2">
                      ool-18e4.dyn.optonline.net.130051007102700823
                    </entry>
                  </row>
                  <row>
                    <entry colname="1">/mod_log_sql/usa.gif</entry>
                    <entry colname="2">
                      ool-18e4.dyn.optonline.net.130051007102700823
                    </entry>
                  </row>
                  <row>
                    <entry colname="1">/mod_log_sql/style_1.css</entry>
                    <entry colname="2">
                      ool-18e4.dyn.optonline.net.130051007102700823
                    </entry>
                  </row>
                </tbody>
              </tgroup>
            </table>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              What if I want to log more than one cookie? What is the
              difference between LogSQLWhichCookie and
              LogSQLWhichCookies?
            </para>
          </question>
          <answer>
            <para>
              As of version 1.17, you have a choice in how you want
              cookie logging handled.
            </para>
            <para>
              If you are interested in logging only one cookie per
              request, follow the instructions in FAQ entry
              <xref linkend="FAQ.Cookie" />
              above. That cookie will be logged to a column in the
              regular access_log table, and the actual cookie you want
              to log is specified with LogSQLWhichCookie. Don't forget
              to specify the 'c' character in LogSQLTransferLogFormat.
            </para>
            <para>
              If, however, you need to log multiple cookies per request,
              you must employ the LogSQLWhichCookies (note the plural)
              directive. The cookies you specify will be logged to a
              separate table (as discussed in section
              <xref endterm="Sect.MultiTable.title"
                linkend="Sect.MultiTable" />
              ), and entries in that table will be linked to the regular
              access_log entries via the unique ID that is supplied by
              mod_unique_id. Without mod_unique_id the information will
              still be logged but you will be unable to correlate which
              cookies go with which access-requests. Furthermore, with
              LogSQLWhichCookies, you do not need to include the 'c'
              character in LogSQLTransferLogFormat.
            </para>
            <para>
              LogSQLWhichCookie and LogSQLWhichCookies can coexist
              without conflict because they operate on entireley
              different tables, but you're better off choosing the one
              you need.
            </para>
          </answer>
        </qandaentry>
        <qandaentry>
          <question>
            <para>
              What are the SSL logging features, and how do I activate
              them?
            </para>
          </question>
          <answer>
            <note>
              <para>
                You do not need to compile SSL support into mod_log_sql
                in order to simply use it with a secure site. You only
                need to compile SSL support into mod_log_sql if you want
                to log SSL-specific data such as the cipher type used,
                or the keysize that was negotiated. If that information
                is unimportant to you, you can ignore this FAQ.
              </para>
            </note>
            <para>
              By adding certain characters to your
              LogSQLTransferLogFormat string you can tell mod_log_sql to
              log the SSL cipher, the SSL keysize of the connection, and
              the maximum keysize that was available. This would let you
              tell, for example, which clients were using only
              export-grade security to access your secure software area.
            </para>
            <para>
              You can compile mod_log_sql with SSL logging support if
              you have the right packages installed. If you already have
              an SSL-enabled Apache then you by definition have the
              correct packages already installed: OpenSSL and mod_ssl.
            </para>
            <para>
              You need to ensure that your database is set up to log the
              SSL data. Issue the following commands to MySQL if your
              access table does not already have them:
            </para>
            <programlisting>mysql&gt; alter table access_log add column ssl_cipher varchar(25);
mysql&gt; alter table access_log add column ssl_keysize smallint unsigned;
mysql&gt; alter table access_log add column ssl_maxkeysize smallint unsigned;</programlisting>
            <para>
              Finally configure httpd.conf to activate the SSL fields.
              Note that this is only meaningful in a VirtualHost that is
              set up for SSL.
            </para>
            <programlisting>&lt;VirtualHost 1.2.3.4:443&gt;
 LogSQLTransferLogFormat AbHhmRSsTUuvcQqz
&lt;/VirtualHost&gt;</programlisting>
            <para>
              You also need to make sure you have the mod_log_sql_ssl
              module loaded as well.
            </para>
            <para>
              The last three characters (Qqz) in the directive are the
              SSL ones; see section
              <xref linkend="Conf.LogSQLTransferLogFormat" />
              in the directives documentation for details of the
              LogSQLTransferLogFormat directive.
            </para>
            <para>
              Restart Apache, then perform some hits on your server.
              Then run the following select statement:
            </para>
            <programlisting>SELECT remote_host,request_uri,ssl_cipher,ssl_keysize,ssl_maxkeysize
FROM access_log
WHERE ssl_cipher IS NOT NULL;</programlisting>
            <table>
              <title></title>
              <tgroup cols="5">
                <colspec colname="1" />
                <colspec colname="2" />
                <colspec colname="3" />
                <colspec colname="4" />
                <colspec colname="5" />
                <thead>
                  <row>
                    <entry colname="1">remote_host</entry>
                    <entry colname="2">request_uri</entry>
                    <entry colname="3">ssl_cipher</entry>
                    <entry colname="4">ssl_keysize</entry>
                    <entry colname="5">ssl_maxkeysize</entry>
                  </row>
                </thead>
                <tbody>
                  <row>
                    <entry colname="1">216.192.52.4</entry>
                    <entry colname="2">/dir/somefile.html</entry>
                    <entry colname="3">RC4-MD5</entry>
                    <entry colname="4">128</entry>
                    <entry colname="5">128</entry>
                  </row>
                  <row>
                    <entry colname="1">216.192.52.4</entry>
                    <entry colname="2">/dir/somefile.gif</entry>
                    <entry colname="3">RC4-MD5</entry>
                    <entry colname="4">128</entry>
                    <entry colname="5">128</entry>
                  </row>
                  <row>
                    <entry colname="1">216.192.52.4</entry>
                    <entry colname="2">/dir/somefile.jpg</entry>
                    <entry colname="3">RC4-MD5</entry>
                    <entry colname="4">128</entry>
                    <entry colname="5">128</entry>
                  </row>
                </tbody>
              </tgroup>
            </table>
          </answer>
        </qandaentry>
      </qandadiv>
    </qandaset>
  </section>
</article>