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  <head>
    <title>The Cricket Reference Guide</title>
  </head>
  <body>
    <h1>The Cricket Reference Guide</h1>
    <p>
      This section is the definitive reference for each and every tag that
      Cricket knows about. Use this section as a reference when you need to
      know the exact format for something, or the exact behavior of a
      certain tag.
    </p>

    <div>
      <h2>File Format</h2>
      <p>
        Cricket config files are simple text files arranged into a
        tree-shaped set of files called a <i>Config Tree</i>. They are
        processed by a Perl module called ConfigTree.pm. This setup would
        make it possible to use one config tree for Cricket and other
        clients of ConfigTree.pm. At this time, there are no other programs
        that use the config tree design, but there may be in the future. It
        was set up this way because the config tree will grow to contain an
        accurate picture of your network; it makes sense to try to leverage
        that information to other network administration tools. The
        overriding philosophy here is duplicated information is bad: it is
        hard to maintain, and it invites silly mistakes.
      </p>
      <p>
        The Cricket config tree is 100% incompatible with MRTG configuration
        files. There are not even any plans to write a converter, though one
        could probably be written. When you choose to use Cricket, it's a
        very good idea to approach your config from a fresh perspective, to
        take maximum advantage of Cricket's features.
      </p>
      <p>
        The comment character for Cricket is &quot;#&quot;. If a
        &quot;#&quot; is found at the beginning of the line (or is preceded
        only by whitespace) then the &quot;#&quot; and everything after it
        will be deleted. Completely blank lines are discarded from the input
        too.
      </p>
      <p>
        The fundamental unit of a config file is a chunk. A chunk is made up
        of one line which begins in column one, and one or more lines which
        have whitespace before them. In this way, you can continue a long
        line to another line by simply inserting a newline and some
        whitespace. When it is glued back together internally, the newline
        and whitespace are replaced by a space. A chunk should have at least
        one word (a group of characters that are not whitespace) at the
        beginning. This word (called the &quot;token&quot; by the code)
        tells ConfigTree.pm what kind of chunk it is dealing with, and what
        kind of parser to use.  If it is an unknown token, ConfigTree.pm can
        be told to ignore it. By default, unknown chunks cause a warning,
        but not a fatal error. Clients of ConfigTree.pm can control this;
        Cricket chooses to ignore unknown chunks.
      </p>

      <div>
        <h3>Text Parser</h3>
        <p>
          This parser is used in cases where free-text is useful, for
          instance in the HTML dictionary. The first two tokens are parsed
          out, and they serve as the chunk type, and the key. Everything
          after these first two tokens is considered the value.
        </p>
      </div>

      <div>
        <h3>Simple Parser</h3>
        <p>
          This parser is used for simple mappings, like the OID mapping. An
          example of a valid OID line is:
        </p>
        <pre>oid  ifInOctets  1.3.6.1.2.1.2.2.1.10</pre>
        <p>
          The format is a token, another token (called the key;
          <tt>ifInOctets</tt> in this case), and finally the value. The
          value can have whitespace in it, but only if it is surrounded by
          double quotes (&quot;). Embedded quotes are not yet supported.
        </p>
      </div>

      <div>
        <h3>Tag/Value Parser</h3>
        <p>
          This is the most useful, and most commonly used parser. Here's an
          example of a Tag/Value chunk:
        </p>
        <pre>
graph   ifInOctets
    color       =   dark-green
    draw-as     =   AREA
    legend      =   "Average bits in"
    y-axis      =   "bits per second"
    scale       =   8,*
        </pre>
        <p>
          Like the others, it parses out two tokens, the chunk type and the
          key. After this, it parses a series of tag/value pairs separated
          by whitespace and the equals sign (&quot;=&quot;). The values must
          be surrounded by quotes to embed whitespace, like the Simple
          Parser. If you repeat a tag, only the second occurrence will be
          used.
        </p>
      </div>

      <div>
        <h3>Miscellaneous</h3>
        <p>
          All tokens and keys are case-insensitive. The tags in a tag/value
          chunk are also case insensitive. The values will have their case
          preserved when they are used by the system.
        </p>
        <p>
          Tag names can have numbers, letters, the period symbol, the dash,
          and the underscore. Avoid using other punctuation, since those
          symbols are used by Cricket internally.
        </p>
        <p>
          OID tags are more limited, to conform with the SNMP spec. A tag in
          an OID dictionary can be made up of numbers and letters. Dashes
          are not allowed.
        </p>
        <p>
          Target names should consist of letters, numbers, dashes and
          underscores. Do not put slashes in them, since they end up being
          used as parts of filenames.
        </p>
        <p>
          Inside of double quotes, on the right side of an equals sign,
          anything goes, with the exception of the double quote itself.
          There is currently no way to include the double quote in a string.
        </p>
        <p>
          Avoid choosing names that begin and end with two dashes (like
          <tt>--default--</tt>). Cricket uses some names like this
          internally, and future additions will make use of these names.
        </p>
        <p>
          The following table shows which tokens are parsed with which
          parsers:
        </p>
        <table>
          <tr> <th>Token</th>      <th>Parser</th>    </tr>
          <tr> <td>target</td>     <td>Tag/Value</td> </tr>
          <tr> <td>datasource</td> <td>Tag/Value</td> </tr>
          <tr> <td>targetType</td> <td>Tag/Value</td> </tr>
          <tr> <td>graph</td>      <td>Tag/Value</td> </tr>
          <tr> <td>view</td>       <td>Tag/Value</td> </tr>
          <tr> <td>color</td>      <td>Simple</td>    </tr>
          <tr> <td>oid</td>        <td>Simple</td>    </tr>
          <tr> <td>html</td>       <td>Text</td>      </tr>
          <tr> <td>event</td>      <td>Tag/Value</td> </tr>
          <tr> <td>rra</td>        <td>Simple</td>    </tr>
        </table>
        <p>
          For some tags, you can put Perl expressions into the value.
          (<tt>inst-names</tt> is one such tag) However, double quotes are
          often useful in Perl expressions. That's problematic, since at
          present there is no way to put quotes into values.  Instead, you
          should use single quotes. Thus it might look something like this:
        </p>
        <pre>
inst-names =   "('Port 1 Ethernet', 'Port 2 Ethernet',
                 'Port 3 FDDI', 'Port 6 FDDI',
                 'Port 7 Ethernet' , 'Port 9 Ethernet')"
                </pre>
      </div>
    </div>

    <div>
      <h2>Dictionary Reference</h2>
      <p>
        In this section are detailed lists of every tag you will find in
        every dictionary.
      </p>
      <p>Jump directly to:</p>
      <ul>
        <li><a href="#target">target</a></li>
        <li><a href="#datasource">datasource</a></li>
        <li><a href="#targettype">targetType</a></li>
        <li><a href="#graph">graph</a></li>
        <li><a href="#view">view</a></li>
        <li><a href="#color">color</a></li>
        <li><a href="#oid">oid</a></li>
        <li><a href="#html">html</a></li>
        <li><a href="#event">event</a></li>
        <li><a href="#rra">rra</a></li>
      </ul>

      <div id="target">
        <h3>The Target Dictionary</h3>
        <p>
          For each target known to Cricket, there is a target dictionary.
          The target dictionary holds all the information needed by Cricket
          to collect and store variables from a component. The target
          dictionary is expanded with respect to itself immediately before
          it is used to collect or display data.
        </p>
        <dl>
          <dt><tt>collect</tt></dt>
          <dd>Default value: <i>not set</i>
            <p>
              If this tag exists, and it is set to <tt>false</tt>, then this
              target will be skipped when the collector comes across it.
              This is useful if you no longer want to collect an obsolete
              target, but you still want it in the config tree so that you
              can look at it with the grapher.
            </p>
          </dd>
          <dt><tt>copy-to</tt></dt>
          <dd>Default value: <i>not set</i>
            <p>
              If this item is set, it tells Cricket to send the data it
              collects somewhere else after it is added to the RRD file. The
              value of this tag is interpreted as a colon separated list of
              two things. The first is where to send the data. The second
              item is used on a case-by-case basis.
            </p>
            <p>
              To send SNMP traps, set <tt>copy-to</tt> to a string like this:
              <tt>trap:public@traphost.company.com</tt>.
            </p>
            <p>
              The traps Cricket sends are marked with an enterprise number
              of "1.3.6.1.4.1.2595.1.1" (which is
              enterprises.webtv.wtvOps.wtvOpsTraps). Their generic type is
              6, and their specific type is 3. The first varbind is the full
              path to the target, including the target name. The other
              varbinds are the actual data. The OID's for these varbinds can
              be ignored. They are not significant.
            </p>
            <p>
              To send SQL updates to a database (see <a
              href="copytosql.html">SQL HOWTO</a>), use a string like this:
            </p>
            <p><tt>sql:driver,user,password</tt></p>
            <p><tt>driver</tt> is a string like: <tt>dbi:Sybase:NMSDB</tt>.</p>
            <p>
              This is a new extension to copy-to and while it is designed to
              work with as many platforms as possible, it may not work with
              all types of databases. It has only been tested against
              SQLServer.
            </p>
            <p>
              New copy-to types can only be added by editing the source to
              the collector. Please send any patches to the Cricket
              maintainer, so others can use your nifty copy-to method.
            </p>
          </dd>
          <dt><tt>directory-desc</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              This string is displayed in the description column of the
              directory selection list, if it is set. If not, the column is
              simply left blank.
            </p>
          </dd>
          <dt><tt>disable-short-desc</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              Hold on tight, this is a weird one. If this is set in the
              dictionary of the first target displayed in the "Targets that
              are available" table, then the table will have only one
              column. This is useful when you have lots of views and don't
              want to lose the space used by the description column.
            </p>
          </dd>
          <dt><tt>display-name</tt></dt>
          <dd>Default value: <i>same as target name</i>
            <p>
              You can use this tag to use a more user friendly name for a
              target for display purposes. If you do not set it, the target
              name itself will be displayed.
            </p>
          </dd>
          <dt><tt>events</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              The pre-1.0.4 syntax of specifying events as a target tag is
              deprecated. The <tt>events</tt> tag is now a view dictionary
              tag.
            </p>
          </dd>
          <dt><tt>hide</tt></dt>
          <dd>Default value: <i>not set</i>
            <p>
              When a target sets this tag to <tt>true</tt>, the grapher
              will not list this target in the hierarchical tree view. You
              might do this when creating multiple-target graphs via
              <tt>targets</tt> or <tt>mtargets</tt> tags, to suppress the
              standalone components to show only the summarized graph.
            </p>
          </dd>
          <dt><tt>inst</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This is the SNMP instance number. Cricket only really needs
              this value to be set correctly if <tt>%inst%</tt> shows up in
              the ds-source tag of the datasources you are collecting. If
              <tt>inst</tt> is set, Cricket will attempt to evaluate it as a
              Perl expression.
            </p>
            <p>
              <span style="color: red">Note</span>: there's no protection
              against side-effects from this expression, so to avoid a
              security problem from an inst like
              <tt>unlink('/etc/motd');</tt> you should make certain your
              config tree is only writable by you.
            </p>
            <p>
              The result of evaluating the instance is examined to see
              whether it is a mapped instance, a scalar, or a vector. If it
              starts with "map(", it is a mapped instance.  The instance
              mapping algorithm is used to derive an instance number from
              the rest of the data in the target (see <a
              href="inst-mapping.html">Instance Mapping</a> for more
              information on this), then the target is processed as though
              the instance number had been a scalar all along.
            </p>
            <p>
              If it is a scalar (i.e. <tt>inst=1</tt>) then it is processed
              normally. If the instance is a vector (i.e.
              <tt>inst="(0..12)"</tt>, or <tt>inst="(1, 3, 5)"</tt>) then
              the target is processed once for each value in the list. The
              target dictionary is expanded with respect to itself for each
              instance, so it's possible to embed <tt>%inst%</tt> into the
              rrd-datafile tag. In fact, it's critical to add
              <tt>%inst%</tt> to some part of the rrd-datafile tag, or else
              the data will all be stored on top of one another in the same
              datafile.
            </p>
            <p>
              <span style="color: red">Note</span>: To protect the instance
              against interpretation, use the perl quote operator: <tt>inst
              = qw(%InstanceName%)</tt>. This is required if instances look
              like floating point numbers to Perl, for example if you have
              an instance like 4.10.
            </p>
          </dd>
          <dt><tt>inst-names</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              When making the instance selector table, Cricket will use
              names from this tag instead of the instances themselves. If it
              will be needed, <tt>inst-names</tt> is eval'ed (just like
              <tt>inst</tt>). For each instance in the <tt>inst</tt> tag,
              Cricket looks for a corresponding entry in the
              <tt>inst-name</tt> vector. If it finds one, it uses that as
              the instance name, otherwise it defaults to the instance it
              fetched from the <tt>inst</tt> tag.
            </p>
          </dd>
          <dt><tt>long-desc</tt></dt>
          <dd>Default-value: <i>unset</i>
            <p>
              This description shows up at the top of a page of graphs, in
              the "Summary" section. There is more room on this page for a
              longer description. You can include your own HTML as long as
              you close all tags that you open. If you don't feel like
              setting this for every target, set it to <tt>%short-desc%</tt>
              in the "--default--" target, and the short description will
              show up on each graph page for every target which does not
              have an explicit long description. (Such is the power of the
              config tree.)
            </p>
          </dd>
          <dt><tt>monitor-thresholds</tt></dt>
          <dd>Default-value: <i>none</i>
            <p>
              Monitor thresholds are discussed in detail in <a
              href="monitor-thresholds.html">this document</a>.
            </p>
          </dd>
          <dt><tt>mtargets</tt></dt>
          <dd>Default-value: <i>none</i>
            <p>
              If this tag exists, then this target is considered by Cricket
              to be a multi-target.  To the collector, this means that it
              simply doesn't need to collect anything, and can skip the
              target.  To the grapher, it means this target will aggregate
              the data from several different targets all onto one set of
              graphs.  It will plot the data from each of the different
              targets all on the same graph.  It assumes that the
              target-type of each of the specified targets is the same.  It
              works best if the graph dictionary for each datasource does
              not specify a color (otherwise you'll end up with more than
              one line with the same color).  It enforces only one AREA
              graph--it will convert the others into LINE2 in order to
              ensure they can be seen. It does not currently support vector
              instances.  Other than that, the syntax matches that for
              "targets". This tag can also be used in connection with the
              mtargets-ops flag to perform arithmetic operations.
            </p>
            <p>
              <i>Note:</i> This tag will not work with vector instances at
              this time. If you absolutely need it to work, you'll need to
              use multiple separate scalar targets to poll the device's
              ports, and then use the <tt>mtargets</tt> tag to graph each of
              the scalar targets.
            </p>
          </dd>
          <dt><tt>mtargets-ops</tt></dt>
          <dd>Default-value: <i>none</i>
            <p>
              This tag is used in connection with the "mtargets" tag. This
              tag lets you perform arithmetic operations on multiple
              targets.  For example, this lets you add multiple targets
              together and graph the results. This tag must either be set to
              an RPN notation, or to a short-hand form, like "sum()".
            </p>
            <p>
              If set to an RPN expression, it should be defined as a comma
              separated list of operations, such as "+","-","*","/".  This
              is used as a RPN calculator, operating on the targets listed
              in the <tt>mtargets</tt> definition. So, if you list three
              targets in your mtargets definition, you could define
              <tt>mtargets-ops="+,+"</tt>, and the result would be a graph
              of the three targets added together.
            </p>
            <p>
              If this tag is set to "sum()", the correct number of pluses
              will be substituted to make a valid RPN expression to sum each
              of the targets in the <tt>mtargets</tt> tag.
            </p>
            <p>
              If this tag is set to "avg()", it will be replaced by the
              correct RPN expression to calculate the average of the targets
              in the <tt>mtargets</tt> tag.
            </p>
            <p>
              The HTML summary section also has the same set of operations
              done to the values there.  The operations are done to each
              datasource defined for that target-type. If you have defined a
              scale for the individual datasource, these operations are done
              on the scaled values.
            </p>
          </dd>
          <dt><tt>order</tt></dt>
          <dd>Default value: 0
            <p>
              The order tag is used to control the order that targets are
              <i>displayed</i>. It has nothing to do with the order that
              they are <i>polled</i>. (Though it might work like that
              someday.) When the display is laid out by the CGI application,
              it sorts the targets from the highest order to the lowest
              order.  Targets which have the same order are sorted
              alpha-numerically within their order.
            </p>
          </dd>
          <dt><tt>persistent-alarms</tt></dt>
          <dd>Default value: <i>false</i>
            <p>
              This tag tells the Monitor agent that if it receives an alarm
              to send traps every time it detects an alarm condition. The
              default behavior is to only send an Alarm/Clear trap. This can
              be useful for sending many SNMP traps into an application
              which can tally the amount of failures, or to have it execute
              a program multiple times. Setting this tag to 'true' turns
              persistent alarming on.
            </p>
          </dd>
          <dt><tt>rrd-datafile</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag tells Cricket where to put the data it collects, and
              where to find the data it will graph. Since there are no
              guarantees about where Cricket will be running from, you
              should use a full path here. The sample-config ships with a
              one-size-fits all definition for rrd-datafile in the root
              Defaults file.  Except for special cases, you can probably use
              it and it will generate the filenames for you automatically.
            </p>
          </dd>
          <dt><tt>rrd-poll-interval</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag is used to set the step size (in seconds) for the RRD
              file when it is first created. This value cannot be changed
              once the RRD file is created, so if you need to change it in
              the config tree, then you must remove the RRD file, forcing
              Cricket to re-create it, to make the change stick. You will,
              of course, lose all the data you have collected so far.  It is
              critical that the collector runs on each target at least as
              often as the rrd-polling-interval, otherwise RRD may mark the
              intervening polling periods as unknown.
            </p>
            <p>
              RRA's are defined in terms of the fundamental polling-interval
              of the RRD. Thus, if you chose to adjust the
              rrd-polling-interval (and then run the collector at a
              non-standard rate) then you should re-visit the RRA
              definitions and probably make adjustments to them. A
              particular example of adjusting rrd-polling-interval would be
              using Cricket to monitor a 155 Mbit OC3 link. Because an SNMP
              Counter32 can wrap in under 5 minutes at bandwidths above 100
              Mbits, it's critical to fetch the data more often, or else RRD
              will not be able to correctly detect and process the counter
              wrap.
            </p>
            <p>
              <!-- XXX --> <i>Hopefully in the next few versions, we will
              have an example of a part of the config tree optimized for
              very fast interfaces.</i>
            </p>
          </dd>
          <dt><tt>rrd-max</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              If this tag is present, it will override the same tag in the
              datasource dictionary. See the entry on <tt>rrd-max</tt> there
              for more information.
            </p>
          </dd>
          <dt><tt>rrd-min</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              If this tag is present, it will override the same tag in the
              datasource dictionary. See the entry on <tt>rrd-min</tt> there
              for more information.
            </p>
          </dd>
          <dt><tt>short-desc</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              This description shows up in the target selection table which
              the CGI program displays. It is a good idea to keep this
              description to one line. You can include your own HTML in it
              as long as you close all tags that you open.
            </p>
          </dd>
          <dt><tt>show-path</tt></dt>
          <dd>Default value: <i>false</i>
            <p>
              When set to <var>true</var>, the current path will be displayed
              in the header for the affected target; with hyperlinked
              path components for easier navigation in the tree.
            </p>
          </dd>
          <dt><tt>snmp</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag is not directly used by Cricket except when it is
              doing instance mapping. However, it is convention (as
              exemplified by the sample-config tree) that this tag should
              hold the SNMP community string, the hostname, and the port
              number in the exact form that is required by the snmp://
              ds-source specification. Thus, ds-sources can simply start
              with <tt>snmp://%snmp%/</tt>, and they will incorporate the
              current host, port, and community string into the ds-source
              tag as soon as they are expanded with respect to the current
              target.
            </p>
            <p>
              When using instance mapping, the <tt>snmp</tt> tag is used
              directly, so it must be present, even if you are using another
              convention to get the data into the ds-source tags.
            </p>
          </dd>
          <dt><tt>snmp-uptime</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              If an <tt>snmp-uptime</tt> tag is specified,
              <tt>collector</tt> will retrieve the specified SNMP object and
              interpret it as the remote device uptime. If the uptime is
              less than the <tt>rrd-poll-interval</tt>, Cricket will assume
              the device has been rebooted and will ignore the previous
              value of any <tt>COUNTER</tt>s on the device (effectively
              instructing RRD to just store the value as a baseline for the
              next sample). This tag should only be used if you <i>must</i>
              use <tt>COUNTER</tt> rather than <tt>DERIVE</tt> as the
              datatype for your data, because checking the uptime will not
              protect you against a host of other causes for spurious
              counter wraps. Use at your own risk, most users should just
              use the <tt>DERIVE</tt> datatype for counters.
            </p>
            <p>Example: <tt>snmp-uptime = 1.3.6.1.2.1.1.3.0</tt></p>
            <p>
              This example shows how to use the system.sysUptime object to
              determine the device uptime. This tag only makes sense in the
              <tt>target --default--</tt> stanza, because specifying it will
              affect all collected counters.
            </p>
            <p>
              If not specified, Cricket will not monitor device uptime for
              reboots.
            </p>
          </dd>
          <dt><tt>summary-loc</tt></dt>
          <dd>Default value: <i>top</i>
            <p>
              This tag controls where the "Summary" box appears on the page.
              There may be instances where you want it on the bottom instead
              of the top. This could be useful for aggregate pages where you
              only care about the graphs and not so much the content. To
              have it display on the bottom, change the tag to 'bottom'.
            </p>
          </dd>
          <dt><tt>targets</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              If this tag exists, then this target is considered by Cricket
              to be a multi-target. To the collector, this means that it
              simply doesn't need to collect anything, and can skip the
              target. To the grapher, it means this target will aggregate
              the data from several different targets all onto one report.
              The syntax is a semi-colon delimited list of targets. The
              target definition can either by fully-qualified, which would
              look like "/router-interfaces/Datacenter1/ds3-1", or
              unqualified, in which case they are assumed to be in the
              current directory.
            </p>
            <p>
              For targets with vector instance definitions, it may also be
              useful to specify which instance you wish to display.  You can
              do that by putting a colon after the target definition.  So,
              it would look something like this:
              targets="/switch-ports/switch-1:3;/switch-ports/
              switch-2:5..7". This would put up instance #3 from switch-1,
              and instance #5, #6, and #7 from switch-2.  Variable expansion
              is handled in the instance definition section as well.
            </p>
            <p>
              This functionality assumes that the target-type of each of the
              specified targets is the same. You also must set a target-type
              for the multi-target itself.  There are some variables which
              control the presentation of this data, which are also listed
              in this reference.
            </p>
          </dd>
          <dt><tt>targets-long-desc</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag sets the text which is displayed above each graph in
              a "targets" multi-target.  It should be an array of the same
              length as the "targets" array. This value overrides the
              default presentation, and also overrides the tag
              targets-short-desc.  Syntax would look like:
              targets-long-desc="('Target1','Target2')".
            </p>
          </dd>
          <dt><tt>targets-short-desc</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              By default above each graph in a targets multi-target page,
              the short-desc of each target being displayed is printed above
              that graph (as well as some other text). This replaces that
              text with this.  It should be an array which matches the
              "targets" array.  The syntax would look the same as for
              targets-long-desc.
            </p>
          </dd>
          <dt><tt>target-type</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag sets the target type for this target. It must be one
              of the target type names from the targetType dictionary.
              Cricket uses the targetType to decide which variables to
              fetch, and how much data to store in the RRD.
            </p>
          </dd>
          <dt><tt>trap-address</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              This tag is used to tell Monitor.pm where to send SNMP traps
              when it needs to send one. The format should be
              community@hostname:port. You can safely leave off community
              and port. The defaults are "public", and "162", respectively.
            </p>
          </dd>
          <dt><tt>unknown-is-zero</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              When this tag is set and the target is part of a multitarget
              which has mtargets-ops set, then data which is unknown will be
              treated as a 0, unless <b>all</b> targets of the multitarget
              are unknown (in which case the value is still unknown). This
              is very useful when trying to create aggregate graphs that sum
              a set of targets that span different time ranges. By default,
              places where one target is unknown and the others are known
              will show on the graph as unknown (blank). In some cases, this
              can result in no graph appearing at all (when the set of known
              datapoints are completely disjoint). Set this flag to "true"
              to avoid this problem.
            </p>
          </dd>
        </dl>
          <dt><tt>use-gprint</tt></dt>
          <dd>Default value: <i>false</i>
            <p>
              When this tag is set, the summary information for the target
              will be embedded in the graph below the legend.
            </p>
          </dd>
        </dl>
        <p>
          In addition, the following tags are set automatically by Cricket
          for your use in other tags in the target dictionary:
        </p>
        <dl>
          <dt><tt>auto-target-name</tt></dt>
          <dd>Default value: <i>automatically set</i>
            <p>
              The short name of the current target. This does not include
              the entire path from the config tree root to the target.
            </p>
          </dd>
          <dt><tt>auto-target-path</tt></dt>
          <dd>Default value: <i>automatically set</i>
            <p>
              The path leading from the base of the config tree to the
              current target.
            </p>
          </dd>
          <dt><tt>auto-base</tt></dt>
          <dd>Default value: <i>automatically set</i>
            <p>
              The config tree root directory. This is especially useful for
              creating paths which you want to be relative to the config
              tree root. For instance, setting rrd-datafile to
              <tt>%auto-base%/../cricket-data/foo.rrd</tt> would put the
              datafile in a directory named cricket-data, next to the base
              of the config tree.
            </p>
          </dd>
          <dt><tt>auto-view</tt></dt>
          <dd>Default value: <i>automatically set</i>
            <p>
              The name of the current view, as selected using the user
              interface. This is sometimes useful to incorporate into
              strings used in the user interface via the HTML dictionary.
            </p>
          </dd>
        </dl>
      </div>

      <div id="datasource">
        <h3>The Datasource Dictionary</h3>
        <p>
          This dictionary tells Cricket everything it needs to know about
          individual datasources. A datasource is a single variable about a
          target which is polled and logged. For instance, a datasource for
          a router interface would be "inbound bandwidth". A separate
          datasource definition is needed for each of the other variables
          that you might want to measure ("outbound bandwidth", for
          instance).
        </p>
        <dl>
          <dt><tt>desc</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              If this tag is set, the value is incorporated into a key at
              the bottom of the page of graphs. This is a very good place to
              put notes about how the value is measured, what uncertainty
              there is in the measurement, etc. You can put arbitrary HTML
              into it, as long as you close any tags that you open. If there
              are no datasources with a description, then no key will be
              printed.  Only datasources with descriptions will be present
              in the key.
            </p>
          </dd>
          <dt><tt>ds-source</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag is used to tell Cricket where to fetch the data from.
              There is a scheme identifier from the beginning until the
              first colon. Everything after the first colon is defined on a
              per-scheme basis. The scheme identifier is case-insensitive.
            </p>
            <p>
              The per-scheme part is expanded with respect to the target
              dictionary immediately before it is resolved into
              measurements, making it possible to plug values from the
              target dictionary into the ds-source at runtime. Likely
              candidates for this substitution include the SNMP hostname and
              community string, the instance number (which is appended to
              table-base OID's), and some or all of the command line for
              EXEC datasources.
            </p>
            <p>Here's a detailed description of each scheme.</p>
            <dl>
              <dt>SNMP</dt>
              <dd>
                <p>
                  These ds-sources look like this:
                  <tt>snmp://community@hostname:port/oid</tt>. The hostname
                  part can be either an IP address or a domain name. It will
                  be resolved with <tt>gethostbyname()</tt> in the latter
                  case. The oid part can include a text label which will be
                  expanded from the OID dictionary.
                </p>
              </dd>
              <dt>EXEC</dt>
              <dd>
                <p>
                  This ds-source is used to tell Cricket to run a shell
                  command in order to fetch the value or values required for
                  a target. After the <tt>exec:</tt> scheme identifier comes
                  an integer followed by a colon, followed by a command
                  (including whatever arguments are required for the
                  command). The number chooses a line of output from the
                  command (starting from line 0). For example, say the
                  "vmstat" program on your system prints this when given the
                  "-s" argument:
                </p>
                <pre>
      350 swap ins
     2982 swap outs
      239 pages swapped in
     3298 pages swapped out
          (etc...)
                </pre>
                <p>
                  Then the following datasource would fetch the number of
                  pages swapped out:
                </p>
                <p><tt>exec:3:vmstat -s</tt></p>
                <p>
                  Note that we allow the text output from the command (i.e.
                  "pages swapped out") to go in to Cricket. As of version
                  0.64, Cricket ignores everything after the first space or
                  tab. It will attempt to interpret the first sequence of
                  non-space characters on the line as a floating point
                  number. Since an integer is a degenerate form of a
                  floating point number, they are acceptable. This behavior
                  holds for all ds-sources, actually, but it is most useful
                  for the EXEC type.
                </p>
                <p>
                  If the initial integer is omitted (and there are no colons
                  in the command line to confuse Cricket) then the line
                  number will be assumed to be 0, and the first line of
                  output will be used as the measurement.
                </p>
              </dd>
              <dt>FILE</dt>
              <dd>
                <p>
                  This ds-source tells Cricket to read a file and find the
                  results on a certain line of that file. The line is
                  specified using the same syntax as EXEC. For example, say
                  the file /tmp/data has two lines in it, like this:
                </p>
                <pre>
100
235
                </pre>
                <p>
                  Then this datasource would always fetch "235" from the
                  file:
                </p>
                <p><tt>file:1:/tmp/data</tt></p>
                <p>
                  Presumably, there would be some other process updating the
                  data file with interesting data from someplace, or else
                  the graph would be a flat line at 235.
                </p>
              </dd>
              <dt>FIELD</dt>
              <dd>
                <p>
                  This datasource is based on the FILE library. It is used
                  to extract specific fields from a file. It is analog to a
                  cricket version of cut(1).
                </p>
                <p>
                  FIELD ds-source look like:
                  <tt>field:filename:key:valuef:keyf:delim</tt>
                </p>
                <p>
                  <tt>key</tt> is the key value to match. <tt>valuef</tt> is
                  which number of the field that should be returned (defaults 
		  to 2).
                  <tt>keyf</tt> is the number of the field that should be 
		  searched for the key.
                  (defaults to 1). <tt>delim</tt> is the field delimiter 
		  (defaults to ':').  For example, if the file /tmp/box 
		  contains the following lines with fields seperated by 
		  spaces:
 
                </p>
                <pre>
thing_1 red 111
thing_2 blue 222
                </pre>
                <p>
		  then this datasource will fetch  "222" from the file:
                </p>
                <p><tt>field:/tmp/box:thing_2:3:1:" "</tt></p>
                <p>
		  There is a single space inside the quotes above.
		  As with FILE above, it's assumed that some other process is
		  updating the data in the file.  Please note that field 
		  numbers start at 1, not 0.
		</p>
              </dd>
              <dt>FUNC</dt>
              <dd>
                <p>
                  This ds-source uses a Perl function to fetch the result.
                  It is not enabled by default, since it requires extra code
                  to be useful, and could be a security vulnerability, if
                  the config tree were not properly protected. To enable it,
                  uncomment the line <tt>use func;</tt> in
                  <tt>collector</tt>.
                </p>
                <p>
                  This ds-source uses Perl's <tt>eval</tt> keyword to
                  evaluate some Perl code at runtime. Usually, this will be
                  a function call to a function you have written yourself
                  and added into <tt>collector</tt>. A good way to add the
                  code portably is to keep it in its own file and
                  incorporate it with the <tt>require</tt> keyword. You will
                  need to be careful to avoid stomping on any data that
                  collector uses, since it will be running your code in its
                  namespace. This should be fixed someday, if many
                  extensions to Cricket use this interface.
                </p>
              </dd>
              <dt>PERFMON <span style="color: red">(warning: still in
                development)</span></dt>
              <dd>
                <p>
                  This ds-source is used to extract perflib information from
                  Win32 hosts which don't use SNMP (or where counters aren't
                  available through SNMP).
                </p>
                <p>
                  Setting up perflib counters in Cricket is not a trivial
                  process, and requires the following: RRDtool 1.1.x,
                  comfort with RPN, and ActiveState perl. This module will
                  not under any circumstances work with any non-Windows OS.
                </p>
                <p>
                  Perflib counter procedures are documented more in depth in
                  the <a href="perfmon.html">Perfmon reference</a> document.
                </p>
                <p>The syntax for a Perfmon datasource is:</p>
                <p>
                  <tt>perfmon:hostname:counter group:counter
                      name:instance:special</tt>
                </p>
                <p>
                  Instance is optional, and only required for instance
                  counters. Unlike the perfmon.exe application in NT.
                  Special is optional as well and is documented in the <a
                  href="perfmon.html">perfmon reference</a> document.
                </p>
                <p>
                  If you're collecting an "instant" perfmon counter,
                  collection is much like getting something from SNMP. Here
                  is an example.
                </p>
                <p><tt>perfmon:%auto-host-name%:System:Processes</tt></p>
                <p>
                  Many perfmon counters return averages which need to be
                  computed against a timebase. This makes collection
                  challenging because you need to first collect several
                  DERIVE-based datasources, and then tie them together with
                  a COMPUTE datasource. The sample-config directory has a
                  large amount of examples with common counters to help, and
                  there is the <a href="perfmon.html">perfmon reference</a>
                  document.
                </p>
                <p>
                  Please note that this piece of Cricket is still not
                  complete and hasn't been tested very well. Please let the
                  developers know if you find any major bugs or have any
                  enhancement suggestions.
                </p>
              </dd>
              <dt>SQL <span style="color: red">(warning: still in
                development)</span></dt>
              <dd>
                <p>
                  This ds-source is used to for extracting counters from a
                  database server. It's still in development and not very
                  robust.
                </p>
                <p>Here is the syntax:</p>
                <p><tt>sql:login:password:query:col:DRIVER</tt></p>
                <p>
                  <tt>col</tt> is used to get a particular column of data
                  returned from the first returned row. Currently any other
                  rows returned get discarded.
                </p>
                <p>
                  <tt>DRIVER</tt> can have colons in it. Cricket's parser
                  will not treat it like separate arguments to the ds itself.
                </p>
                <p>Here is an example:</p>
                <p>
                  <tt>sql:anonymous::select top 1 samplevalue from
                  samplednumericdata where idsamplednumericdatasource =
                  'C04E3055-B282-4EE9-9F5D-CB46DC45C988' order by
                  timesampled desc:1:dbi:Sybase:NMSDB</tt>
                </p>
              </dd>
              <dt>WBEM <span style="color: red">(warning: still in
                development)</span></dt>
              <dd>
                <p>
                  This ds-source is used to extract WBEM information from
                  Win32 hosts. Currently this requires ActiveState Perl and
                  will not run under any non-Windows OS. It has not been
                  tested for compatibility against a UNIX WBEM data provider.
                </p>
                <p>The syntax for a WBEM ds-source syntax:</p>
                <p><tt>wbem:%auto-target-name%:wbem-namespace:wbem-object:counter:instance</tt></p>
                <p>
                  Here is an example to get the same counter as noted in the
                  PERFMON provider example.
                </p>
                <p><tt>wbem:%auto-target-name%:root\\cimv2:Win32_PerfFormattedData_PerfOS_System:Processes</tt></p>
                <p>
                  The WBEM provider does not support authentication, so
                  security settings may not allow this to work properly.
                </p>
                <p>
                  More information can be found in the <a
                  href="win2kwmi.html">Installing Cricket on Win2k to
                  Monitor WMI Counters</a> document.
                </p>
              </dd>
            </dl>
            <p>
              Datasources are batched together and executed with as few
              network transactions or shell executions are possible. For
              instance, if you are fetching six datasources from the same
              hostname, all six datasources will be rolled into one SNMP
              request.  Likewise, if you are fetching 3 different lines from
              the results of the same command, that command will be run only
              once.
            </p>
            <p>
              Schemes are expected to return their data as an array of
              numbers. If the values are of the form "XXX@YYY", then the
              measurement XXX will be recorded as being taken at time YYY.
              The time must be in the form of a Unix <tt>time_t</tt>, i.e.
              number of seconds since 1970. Currently, this feature is only
              supported by the EXEC and FILE schemes. RRD imposes the
              restriction that data can <b>only</b> be added in strictly
              ascending time order. Each datasource which has a time in it
              should have a matching time. If this is not the case, Cricket
              will log a warning, but use the first time it found in the
              array.
            </p>
            <p>
              You might use this feature if you are fetching the data from
              another data collection system which is operating on a
              different polling cycle than Cricket. You could use a shell
              script to fetch the data from the other system, along with the
              time the data was sampled. Then you could format the result
              into the "XXX@YYY" format, and print it to standard out for
              Cricket to read.
            </p>
            <p>
              New schemes can be added to Cricket with minimal effort. Use
              the file <tt>lib/exec.pm</tt> as your guide, then add a
              <tt>use</tt> statement for your new <tt>.pm</tt> file to
              <tt>collector</tt>.
            </p>
          </dd>
          <dt><tt>rrd-ds-type</tt></dt>
          <dd>Default value: GAUGE
            <p>
              The DS type is used by RRD to know how to interpret the
              numbers fetched from this datasource. There are three
              possibilities:
            </p>
            <dl>
              <dt>GAUGE</dt>
              <dd>
                <p>
                  The measurement will be directly copied into the RRD
                  datafile without any extra processing. Examples of this
                  type of measurement include readings from thermometers,
                  percent disk space free, etc.
                </p>
                <p>
                  The distributed Defaults file sets rrd-min to zero.
                  If your GAUGE target can support negative values, set
                  rrd-min to "undef", or to the actual minimum value.
                </p>
              </dd>
              <dt>COUNTER</dt>
              <dd>
                <p>
                  The measurements from COUNTER datasources will be treated
                  like SNMP counters. An SNMP counter increases
                  monotonically until a fixed wrap-around point (usually
                  either 2^31-2 or 2^63-2, depending on the size of the data
                  type). To convert a COUNTER measurement into a rate (for
                  instance, "count of octets" to "octets per second") RRD
                  subtracts the previous value from the current one, and
                  adjusts for any wraparound conditions. Any SNMP variable
                  which is marked with the SNMP "COUNTER" data type would
                  normally have its <tt>rrd-ds-type</tt> set to COUNTER, but
                  unless your datasource guarantees a monotonous increase,
                  it is better to use DERIVE with an rrd-min of zero.
                </p>
              </dd>
              <dt>DERIVE</dt>
              <dd>
                <p>
                  DERIVE is like COUNTER, but there is no overflow check, so
                  negative rates are possible. This datasource type would be
                  useful when you have a count of something (which may
                  increase and decrease), and you want to graph the rate of
                  change.
                </p>
                <p>
                  With an rrd-min of zero, the DERIVE datasource type acts
                  like COUNTER, except that negative samples are treated as
                  unknown. Handling SNMP COUNTERs in this fashion helps
                  reduce the occurrence of spikes in the graphs. Negative
                  values can result from restarting the device or
                  implementation errors in its SNMP agent, and are common
                  enough to really recommend using DERIVE rather than
                  COUNTER.
                </p>
              </dd>
              <dt>ABSOLUTE</dt>
              <dd>
                <p>
                  ABSOLUTE is for COUNTERs which get reset upon reading.
                  Some SNMP variables have this property. Using ABSOLUTE
                  instead of COUNTER tells RRD to compute the rate assuming
                  the value is an absolute count of octets (or whatever)
                  during the last polling period.
                </p>
              </dd>
            </dl>
            <p>
              The datasource type names are case-insensitive. They are
              passed directly through to RRD when the RRD file is created.
              If the datasource type is changed later, you must use
              <tt>rrd-tune</tt> to apply the change to the underlying RRD
              file. For more information about them, consult the RRD
              documentation for the <tt>create</tt> command.
            </p>
          </dd>
          <dt><tt>rrd-heartbeat</tt></dt>
          <dd>Default value: 1800 <i>(value is in seconds)</i>
            <p>
              The heartbeat for a datasource is the number of seconds that
              can pass between updates before the datasource is marked
              unknown. If this tag is changed after the RRD file has been
              created, then the <a href="#rrd-tune">rrd-tune</a> tool must
              be used to apply the changes to the existing RRD's.
            </p>
          </dd>
          <dt><tt>rrd-max</tt></dt>
          <dd>Default value: U
            <p>
              This tag is used to set the RRD maximum value parameter. If
              RRD gets a value higher than this number, it will throw the
              data away, instead of adding it to the RRA. This can be used
              to filter bad data, though it could be argued it would be
              better to simply avoid fetching bad data in the first place.
              When it is set to "U" (for unknown), RRD does not attempt to
              check incoming data against an upper bound.
            </p>
            <p>
              If the tag <tt>rrd-max</tt> is present in the target
              dictionary, it will override the value found in the datasource
              dictionary. This makes is possible to assign different maxima
              to different targets.
            </p>
            <p>
              If this value is changed after the underlying RRD file has
              been created, the <tt>rrd-tune</tt> script must be used to
              apply the changes.
            </p>
          </dd>
          <dt><tt>rrd-min</tt></dt>
          <dd>Default value: U
            <p>
              Like <tt>rrd-max</tt>, this tag is passed through to RRD
              unchanged. It can be used to apply an upper bound to data
              submitted to RRD.
            </p>
            <p>
              Also like <tt>rrd-max</tt>, if <tt>rrd-min</tt> appears in the
              target dictionary, it will override the <tt>rrd-min</tt> in
              the datasource dictionary.
            </p>
          </dd>
        </dl>
      </div>

      <div id="targettype">
        <h3>The TargetType Dictionary</h3>
        <p>
          The TargetType dictionary tells Cricket which datasources to
          gather together for a certain kind of target. Unlike other
          dictionaries, keys in this one can occur multiple times.
        </p>
        <dl>
          <dt><tt>ds</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Each <tt>ds</tt> tag tells Cricket about a variable it will be
              fetching. The value of the tag must be comma-separated list of
              known datasource names.
            </p>
          </dd>
          <dt><tt>view</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Each <tt>view</tt> specifies a comma-delimited list of views
              associated with this target type. These views must be defined
              in separate view dictionary entries on the config tree
              inheritance path of targets of this target type. This implies
              the view entries do not have to be defined in the same
              Defaults file in which the TargetType dictionary referencing
              them appears. However, for a cleaner, easier to read config
              tree, define view entries in the same Defaults file as the
              TargetType dictionary that references them.
            </p>
            <p>
              The pre-1.0.4 syntax of defining views with the TargetType
              <tt>view</tt> tag is deprecated.
            </p>
          </dd>
        </dl>
      </div>

      <div id="graph">
        <h3>The Graph Dictionary</h3>
        <p>
          The graph dictionary controls how individual datasources are
          displayed when it comes time to graph them. It also controls
          display attributes of statistical summary for this data source on
          the HTML page which embeds the graph image(s). Each named graph
          dictionary entry (not <tt>--default--</tt>) should share the name
          of a datasource dictionary entry. In this respect, the graph
          dictionary could be merged with the datasource dictionary.
          However, the separation permits separate administration of
          datasource definition/collection and display properties in graphs.
        </p>
        <p>
          Cricket variables in graph tags (i.e. %myvar%) are expanded with
          respect to a target. For example, in the graph dictionary entry
          for a datasource, you could specify <tt>y-max =
          %specific-y-max%</tt>, then set the tag <tt>specific-y-max</tt> on
          a per-target basis. The association between targets and graph
          dictionary entries is controlled by the TargetType dictionary for
          the apporpriate target type (because the graph dictionary names
          match datasource dictionary names).
        </p>
        <p>
          Graph <tt>--default--</tt> dictionary entries can be used to
          define default datasource graph attributes (such as default line
          thickness via the <tt>draw-as</tt> tag).
        </p>
        <p>
          If your config tree does not utilize views, you should use graph
          <tt>--default--</tt> dictionary entries to define non-datasource
          specific graphing attributes. These tags include:
          <tt>default-ranges</tt>, <tt>height</tt>, <tt>height-hint</tt>,
          <tt>interlaced</tt>, <tt>graph-format</tt>, <tt>vrule-color</tt>,
          <tt>width</tt>, and <tt>width-hint</tt>.
        </p>
        <p>
          If your config tree utilizes views, these attributes should
          instead be defined in view dictionary entries and these tags are
          defined in the <a href="#view">view dictionary section</a>. For a
          config tree that utilizes views, defining non-datasource specific
          graphing tags in graph <tt>--default--</tt> entries is deprecated.
        </p>
        <dl>
          <dt><tt>bytes</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              If this is set to true, then the conversion to SI units will
              use powers of 2 instead of powers of 10. For instance, if a
              router is reporting that it's moving 1048576 bits per second
              through a particular interface, and "bytes" is set to 1 (or
              "true") then the value will be reported in the HTML summary as
              1 Mbit/sec. Without the <tt>bytes</tt> tag, the value would be
              reported at 1.04 Mbit/sec, which is slightly misleading. When
              measuring very large numbers of bytes, the difference can be
              significant (4.9% in the case of Mega sized measurements, 7.3%
              in the case of Giga sized measurements). This is the major
              cause of discrepancies between Cricket and some commercial
              tools, so make sure it's set appropriately.
            </p>
            <p>
              The numbers on the vertical axis of a graph are scaled by powers
              of 2 if the bytes tag is set to true for any of the datasources
              on the graph.
            </p>
          </dd>
          <dt><tt>color</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Use the <tt>color</tt> tag to explicitly control the color of
              the datasource as it appears both on the graph, and in the HTML
              summary. If this is left unset, then Cricket will automatically
              choose colors according to the <tt>--order--</tt> key in the <a
              href="#color">color dictionary</a>. If you choose to set it,
              either set it to one of the color names in the color dictionary,
              or set it to an HTML-style color specification without the pound
              sign. For instance, to make a datasource's line red, set color
              to "ff0000".
            </p>
          </dd>
          <dt><tt>draw-as</tt></dt>
          <dd>Default value: <i>?<!-- XXX --></i>
            <p>
              This tag tells Cricket how to draw the datasource on the graph.
              The choices are as follows:
            </p>
            <dl>
              <dt><tt>AREA</tt></dt>
              <dd>
                Draws a filled-in shape representing the value of the
                datasource over time.
              </dd>
              <dt><tt>STACK</tt></dt>
              <dd>
                Like LINE or AREA, but the data values are stacked.
                Note that the first graph must be drawn as an AREA
                or a LINE and determines how the STACKed values are drawn.
              </dd>
              <dt><tt>LINE1</tt></dt><dd>Uses a thin line.</dd>
              <dt><tt>LINE2</tt></dt><dd>Uses a medium line.</dd>
              <dt><tt>LINE3</tt></dt><dd>Uses a heavy line.</dd>
            </dl>
          </dd>
          <dt><tt>draw-max-as</tt></dt>
          <dd>Default value: <i>LINE2</i>
            <p>
              Same as <tt>draw-as</tt> but for maximums enabled with
              <tt>show-max</tt>.
            </p>
          </dd>
          <dt><tt>legend</tt></dt>
          <dd>Default value: <i>datasource name</i>
            <p>
              Using <tt>legend</tt> allows you to customize the datasource
              name which is displayed on the graph's legend, and in the HTML
              summary. If you don't use a <tt>legend</tt> tag, the name of the
              datasource (as specified by the <tt>ds</tt> tag in the
              targetType dictionary) will be used.
            </p>
          </dd>
          <dt><tt>max-color</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Same as <tt>color</tt> but for maximums enabled with
              <tt>show-max</tt>.
            </p>
          </dd>
          <dt><tt>precision</tt></dt>
          <dd>Default value: <i>2</i>
            <p>
              You can adjust the number of decimal points in the HTML summary
              values using the <tt>precision</tt> tag. The default is two. If
              you simply want the value displayed to be rounded to the nearest
              integer, set <tt>precision</tt> to zero. Alternatively, you can
              set it to the string "integer".
            </p>
          </dd>
          <dt><tt>scale</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              If <tt>scale</tt> is set, then the datasource is run through a
              computation (usually a simple scaling operation) before it it
              plotted or listed in the HTML summary. The tag is interpreted as
              a string of operations that will be executed by a Reverse Polish
              Notation (RPN) calculator, separated by commas. When the
              expression begins executing, the current value of the datasource
              is already on the stack. Thus setting <tt>scale</tt> to "8,*"
              will multiply the datasource by 8 before plotting it.
            </p>
            <p>
              The RPN operations available are "+" (plus), "-" (minus), "*"
              (multiply), "/" (divide), and "LOG" (take the natural logarithm
              of the top of the stack). Any other token is pushed onto the
              stack as a number. The top of the stack at the end of the string
              of operations is taken as the scaled value.
            </p>
            <p>
              This feature is very useful when plotting bits per second from a
              router interface. Routers tend to report bandwidth in bytes per
              second, but humans tend to think about link capacity in bits per
              second. Using a <tt>scale</tt> tag of "8,*" can bridge this gap
              by scaling the bytes per second from the router into bits per
              second for human use.
            </p>
          </dd>
          <dt><tt>show-avg-max</tt></dt>
          <dd>Default value: <i>true</i>
            <p>
              This controls the amount of summary data shown for this
              datasource at the top of the graph page. If set to true, Cricket
              makes an extra call to RRD Tool to fetch the average and the
              maximum for the current day of data. If set to false, only the
              current reading is shown.
            </p>
          </dd>
          <dt><tt>show-max</tt></dt>
          <dd>Default value: <i>false</i>
            <p>
              This controls whether or not the maximums stored for a data
              source are drawn on the graph.
            </p>
            <p>
              Data collected by Cricket is consolidated in RRD databases in
              several ways, so as time passes, you lose high-resolution data
              points, as they are replaced by summary data.  The most common
              consolidation function is AVERAGE, which shows you the average
              of the data points which were consolidated. But there are also
              MIN and MAX, for example, and this data is calculated and stored
              by default. show-max turns on display of the MAX consolidated
              data.
            </p>
            <p>
              This is useful for seeing what the peak levels were at some
              point in the past, since this information is lost by AVERAGE.
            </p>
          </dd>
          <dt><tt>si-units</tt></dt>
          <dd>Default value: <i>true</i>
            <p>
              Setting this tag to "false" will prevent Cricket from
              transforming the value printed in the HTML summary into SI units
              (i.e. 2000 bytes/sec is transformed into 2 kbytes/sec). The
              scale on the graph, however, will still have the transformation
              done to it. Set this tag to "false" for items that are not
              typically counted with SI units, like system load average.
            </p>
            <p>Here are the SI units that are used by Cricket:</p>
            <table>
              <tr><th>Symbol</th> <th>Magnitude</th> <th>Name</th></tr>
              <tr><td>a</td>      <td>10e-18</td>    <td>Ato</td></tr>
              <tr><td>f</td>      <td>10e-15</td>    <td>Femto</td></tr>
              <tr><td>p</td>      <td>10e-12</td>    <td>Pico</td></tr>
              <tr><td>n</td>      <td>10e-9</td>     <td>Nano</td></tr>
              <tr><td>&#181;</td> <td>10e-6</td>     <td>Micro</td></tr>
              <tr><td>milli</td>  <td>10e-3</td>     <td>Milli</td></tr>
              <tr><td>k</td>      <td>10e3</td>      <td>Kilo</td></tr>
              <tr><td>M</td>      <td>10e6</td>      <td>Mega</td></tr>
              <tr><td>G</td>      <td>10e9</td>      <td>Giga</td></tr>
              <tr><td>T</td>      <td>10e12</td>     <td>Terra</td></tr>
              <tr><td>P</td>      <td>10e15</td>     <td>Peta</td></tr>
              <tr><td>E</td>      <td>10e18</td>     <td>Exa</td></tr>
            </table>
            <p>
              Note that on graphs, 'milli' is denoted by 'm'. In the HTML
              summary, where there is more room, Cricket uses the less
              ambiguous 'milli'.
            </p>
          </dd>
          <dt><tt>space</tt></dt>
          <dd>Default value: <i>one space</i>
            <p>
              This tag can be used by the extremely fastidious user to control
              the HTML summary. Usually, one space is exactly what you'd want
              between the value and the unit specifier of the value. However,
              for certain units, like the degree sign, no space is called for.
              In this case, set <tt>space</tt> to "", the empty string.
            </p>
          </dd>
          <dt><tt>units</tt></dt>
          <dd>Default value: <i>the value of the <tt>y-axis</tt> tag</i>
            <p>
              In the HTML summary, the <tt>units</tt> tag is appended after
              the value of the datasource. If a datasource is collecting
              bandwidth information, for instance, it would make sense to set
              <tt>y-axis</tt> to "bits per second", since there is plenty of
              room for it. In the legend, where room is more limited, it would
              be better to set <tt>units</tt> to "bps", instead of letting it
              default to "bits per second".
            </p>
          </dd>
          <dt><tt>y-max</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>
              Use this tag (and its counterpart, <tt>y-min</tt>) to explicitly
              set the default vertical scale for this datasource when it is
              graphed. Often multiple datasources are graphed together, so
              this tag is better set in a view entry. Refer to the <a
              href="#view"> the view dictionary section</a>. Presence of this
              tag disables auto-scaling, so you should set <tt>y-max</tt> and
              <tt>y-min</tt> together if you use this functionality.
            </p>
          </dd>
          <dt><tt>y-min</tt></dt>
          <dd>Default value: <i>unset</i>
            <p>Refer to <tt>y-max</tt>.</p>
          </dd>
        </dl>
      </div>

      <div id="view">
        <h3>The View Dictionary</h3>
        <p>
          A view dictionary entry is a container for display elements. In
          particular, a view is a group of datasources to be displayed
          together with a particular set of display attributes/options. The
          same datasource can appear in multiple views. The datasource
          specific graph attributes are defined in graph dictionary entries,
          but other features of the graph and the HTML page in which the graph
          is embedded are configured in the view entry and thus can vary from
          view to view. As you navigate through the Cricket Grapher the choice
          of graph pages presented for a given target are the views defined
          for that target (via the view list in the TargetType dictionary).
        </p>
        <p>
          The most important view tag is <tt>elements</tt>, as this tag
          specifies the list of datasources (with their associated graph
          dictionary entries) to be included in the view. The
          <tt>elements</tt> tag is the replacement for the space-delimited
          datasource list in the TargetType dictionary view tag in older
          (pre-1.0.4) versions of Cricket.
        </p>
        <p>
          Views are not required. If a target type does not include any views,
          the Grapher will present the user with a list of datasources. But
          views unlock the full flexibility of the Cricket Grapher.
        </p>
        <p>
          Cricket variables in view tags (i.e. %myvar%) are expanded with
          respect to a target. The association between targets and view
          dictionary entries is controlled by the <a
          href="#targettype">TargetType dictionary</a> for the apporpriate
          target type.
        </p>
        <p>
          It is not uncommon for view names to contain space characters. Such
          names are permitted (and parseable) in the config tree. Simply
          enclose the name in double quotes:
        </p>
        <pre>
view   "Traffic Flow"
elements = "ifInOctects, ifOutOctets"
        </pre>
        <p>Here is the list of view dictionary tags:</p>
        <dl>
          <dt><tt>confidence-band-scale</tt></dt>
          <dd>Default value: 2
            <p>
              This tag is ignored unless the <tt>holtwinters</tt> is present
              and set to to true. In that case, it controls the multiple of
              the deviations (RRA CF DEVPREDICT) used to display confidence
              bands on the graph.
            </p>
          </dd>
          <dt><tt>default-ranges</tt></dt>
          <dd>Default value: "d:w"
            <p>
              The default set of temporal scales, colon-separated, for which
              graphs are initially displayed. For example, specifying
              <tt>default-ranges="d"</tt> for a view means only the daily
              graph will be generated, instead of both the daily and weekly
              graphs. Of course, the Cricket grapher permits the user to
              select another temporal scale once the default is rendered.
            </p>
          </dd>
          <dt><tt>elements</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              The <tt>elements</tt> tag specifies a list of datasources (with
              their associated graph dictionary entries) to be included in the
              view. These datasources are presumed to be listed in the
              <tt>ds</tt> tag of any TargetType dictionary to which the view
              belongs. The <tt>elements</tt> tag may either be comma-delimited
              (the preference) or space-delimited (to match pre-1.0.4 syntax).
            </p>
            <p>
              Selecting a view in the Grapher without the <tt>elements</tt>
              tag defined in the Config Tree is one cause of the "No graph to
              make?" error in your web server log.
            </p>
          </dd>
          <dt><tt>events</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag is interpreted by the grapher as a comma-separated list
              of events to fetch from the <tt>events</tt> dictionary, and add
              to the graph in the form of vertical lines.
            </p>
          </dd>
          <dt><tt>graph-format</tt></dt>
          <dd>Default value: <i>png</i> (for 4.0+ browsers), <i>gif</i> otherwise
            <p>
              Set this tag to 'gif' to get RRD Tool to create GIFs. The GIFs
              created by RRD are big and slow, because they do not use
              patented compression techniques. Cricket will use GIFs if the
              browser will not support PNG's. This tag is likely to appear in
              view <tt>--default--</tt> entry.
            </p>
            <p>
              Note that RRD Tool 1.1.x does not support GIFs. It does support
              other image formats that may be incorporated into a future
              Cricket release.
            </p>
          </dd>
          <dt><tt>height</tt></dt>
          <dd>Default value: 200
            <p>
              This tag defines the requested height of the data area of the
              graph. This value is passed into RRD, which then draws the
              actual image somewhat bigger, in order to leave room for the
              margin, the scales, and the legend. This tag is likely to appear
              in a view <tt>--default--</tt> entry.
            </p>
          </dd>
          <dt><tt>height-hint</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              HTML defines image sizing tags that allow the browser to layout
              the page more efficiently. Using the Cricket's size hints, you
              can control what image sizing tags Cricket generates in its HTML
              output. Most browsers will attempt to scale the image if the
              size hints passed in via HTML do not match the actual size of
              the image. The result is a hard-to-read graph that took too long
              to draw. Thus it is <b>critical</b> that if you choose to use
              sizing hints to help the browser layout the page, you make them
              precisely the same as the size of the generated image.
            </p>
            <p>
              Because RRD pads the image with extra space, it's not possible
              for Cricket to guess the finished size of the image using the
              <tt>width</tt> and <tt>height</tt> tags. Instead, you need to
              find this number yourself by measuring an actual image produced
              by RRD. In Netscape Navigator, you can do this by right clicking
              on the image, then choosing <i>Open this Image</i>. Once the
              image is loaded, check the title bar for the actual size of the
              image.
            </p>
            <p>
              Like <tt>height</tt>, this tag is likely to appear in a view
              <tt>--default--</tt> entry.
            </p>
          </dd>
          <dt><tt>holtwinters</tt></dt>
          <dd>Default value: <i>false</i>
            <p>
              If present and set to true, the <tt>holtwinters</tt> tag tells
              the Grapher to display aberrant behavior detection options on
              the graph and HTML summary page. These options include display
              of aberrant behavior recorded in the FAILURES RRA and predicted
              confidence bands for the observed time series (based on
              Holt-Winters Forecasting, hence the tag name). The underlying
              target must have RRD Tool aberrant behavior detection enabled
              (requires RRD Tool 1.1.x).
            </p>
            <p>
              If this tag is enabled, the <tt>elements</tt> tag must contain
              only a single datasource; otherwise, an error will be generated.
              Furthermore, the <tt>default-ranges</tt> tag is ignored for a
              view with <tt>holtwinters=true</tt>.
            </p>
            <p>
              Note that it is not required to define views with
              holtwinters=true simply because RRD Tool aberrant behavior
              detection is enabled.
            </p>
          </dd>
          <dt><tt>interlaced</tt></dt>
          <dd>Default value: false
            <p>
              Set this tag to true to enable interlaced images for this view.
              An interlaced image will appear to "fade in" in most web
              browsers.
            </p>
          </dd>
          <dt><tt>paint-nan</tt></dt>
          <dd>Default value: <i>false</i>
            <p>
              Setting <tt>paint-nan</tt> to true for a view will shade the
              background of the graph with a pinkish hue for any time period
              in which one of the datasources included in the view has missing
              (NaN) data. This option should not be used for views containing
              datasources with the graph key <tt>draw-as=AREA</tt> or
              <tt>STACK</tt>.
            </p>
          </dd>
          <dt><tt>rrd-graph-args</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag can be used to pass through arguments to the RRD Tool
              graph command. For example, to make the canvas that the graph is
              drawn on appear black, set <tt>rrd-graph-args</tt> to "-c
              CANVAS#000000". This tag is split on whitespace before it is
              sent to RRD Tool, so it is not possible at this time to send
              arguments with embedded whitespace to RRD Tool.
            </p>
            <p>
              As a second example (running RRD Tool 1.1.x), to change the
              default font for in-graph text to 12 pt Times, set
              <tt>rrd-graph-args</tt> to "--font DEFAULT:12:times.ttf". This
              example assume times.ttf is available on the path in the
              environment in which the Cricket grapher is running.
            </p>
          </dd>
          <dt><tt>vrule-color</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Vertical rules are lines added to the graph by Cricket to help
              you visually find patterns in the data related to time of day. A
              vertical rule is placed at each "zero time" which appears on a
              graph. For an daily graph, a zero time is midnight. For a weekly
              graph, a zero time is the beginning of the most recent Monday.
              For a monthly graph, a zero time is the first day of the month.
              For a yearly graph, a zero time is the first day of the year. At
              this time, the definition of zero time for a given scale is
              hardcoded into Cricket's grapher.cgi script.
            </p>
            <p>
              To enable vertical rules, use the <tt>vrule-color</tt> tag to
              choose a color for them defined in the color dictionary. That's
              all there is to it. If <tt>vrule-color</tt> is defined, Cricket
              will automatically add the vertical rules for you.
            </p>
          </dd>
          <dt><tt>width</tt></dt>
          <dd>Default value: 500
            <p>
              Similar to <tt>height</tt>, this is the width of the data area
              of the graph. The actual width of the resulting image will
              differ.
            </p>
          </dd>
          <dt><tt>width-hint</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Similar to <tt>height-hint</tt>, this controls the value used by
              Cricket for the width tag in its HTML output. See
              <tt>height-hint</tt> for more information.
            </p>
          </dd>
          <dt><tt>y-max</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              Using this tag (and its counterpart, <tt>y-min</tt>) you can
              explicitly control the vertical scale of the graph and override
              any datasource-specific <tt>y-max</tt> or <tt>y-min</tt> tag
              defined in a graph dictionary entry. For example, these tags
              might be useful when you are graphing some value which should
              normally be very tightly bounded (for instance between 0 and 1
              second), but occasionally jumps far above 1 second. In this
              case, all variation under one second will be essentially
              invisible on the graph, unless you set the <tt>y-min</tt> to 0
              and the <tt>y-max</tt> to 1.
            </p>
            <p>
              Using <tt>y-max</tt> or <tt>y-min</tt>, disables auto-scaling,
              and so you must explicitly set both of them (although they need
              not both be set in the same dictionary entry, <tt>y-min=0</tt>
              could appear in a view <tt>--default--</tt> entry). Note that
              for many situations, the default auto-scaling is reasonable.
            </p>
            <p>
              If the <tt>y-max</tt> tag is not defined in view entries, but
              does appear in graph datasource-specific entries, <tt>y-max</tt>
              for the view will default to the maximum per-datasource
              <tt>y-max</tt>. Similarly, <tt>y-min</tt> for the view defaults
              to the minimum per-datasource <tt>y-min</tt>.
            </p>
          </dd>
          <dt><tt>y-min</tt></dt>
          <dd>Default value: <i>none</i>
            <p>Refer to <tt>y-max</tt>.</p>
          </dd>
        </dl>
      </div>

      <div id="color">
        <h3>The Color Dictionary</h3>
        <p>
          The color dictionary is used to configure Cricket's auto-color
          selection system and to map color names to HTML-style color
          specifications (without the pound sign). Every key, except for the
          special key <tt>--order--</tt> is considered a color name, and should
          have a color specification. The special key <tt>--order--</tt> is used
          to tell Cricket what order to assign the colors when doing
          auto-selection.
        </p>
        <p>
          An HTML-style color specification consists of three hex numbers
          ranging from <tt>00</tt> to <tt>ff</tt>. The numbers represent the
          intensity of the red, green, and blue components of the final color.
          For an example of a correctly configured color dictionary, see the
          Defaults file in the root of the sample config tree.
        </p>
      </div>

      <div id="oid">
        <h3>The OID Dictionary</h3>
        <p>
          The OID dictionary is a convenient place to put OID's to make the
          config files more readable. Before any SNMP operation, the
          user-supplied OID is scanned. Any text parts of the OID that match an
          entry in the OID dictionary get replaced. Note that this is a separate
          process from variable expansion, for historical reasons. The keys and
          values in this table are separated by whitespace. Each entry starts
          with the keyword "OID".
        </p>
        <p>
          In keeping with the conventions of ASN.1 and SNMP, OID names are case
          insensitive, must start with a letter, and can otherwise consist of
          letters and numbers.
        </p>
      </div>

      <div id="html">
        <h3>The HTML Dictionary</h3>
        <p>
          The HTML dictionary holds components of the UI that is created by the
          grapher using HTML. Before it is used, the HTML dictionary is expanded
          with respect to itself.
        </p>
        <dl>
          <dt><tt>auto-error</tt></dt>
          <dd>Default value: <i>any errors generated on this page</i>
            <p>
              Any runtime errors that the grapher finds while attempting to
              create the page are added to this tag. It is usually referenced in
              the <tt>page-footer</tt>.
            </p>
            <p>
              Note that only errors that Cricket can find while it's running
              will show up here. Problems finding the Perl interpreter, or
              parsing <tt>grapher.cgi</tt> will still show up in the webserver's
              error log.
            </p>
          </dd>
          <dt><tt>auto-long-version</tt></dt>
          <dd>Default value: <i>the contents of the VERSION file</i>
            <p>
              This is the complete version string, including the version number
              and the time it was packaged for release.
            </p>
          </dd>
          <dt><tt>auto-short-version</tt></dt>
          <dd>Default value: <i>the version number</i>
            <p>
              This is simply the version number from the complete Cricket
              version string.
            </p>
          </dd>
          <dt><tt>auto-title</tt></dt>
          <dd>Default value: <i>the title</i>
            <p>
              This tag is set by the grapher to the title it expects to use on
              this page. It is normally referenced in the <tt>head</tt> tag.
            </p>
          </dd>
          <dt><tt>body-options</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This tag is incorporated into the HTML body tag. This is the
              perfect place to set a background color. It's not useful for much
              else, unless you want your graphs to play a MIDI file in the
              background.
            </p>
          </dd>
          <dt><tt>head</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This is HTML that will be inserted between the &lt;head&gt; and
              &lt;/head&gt; tags. It can be used to incorporate a cascading
              style sheet into the Cricket user interface. This would allow you
              to easily control aspects of the UI design that are hardcoded in
              the source code.
            </p>
            <p>
              To incorporate a CSS called "cricket.css", use a <tt>head</tt> tag
              like this:
            </p>
            <table>
              <tr>
                <td>
                  <pre>
html  head
&lt;link rel="stylesheet" src="cricket.css" type="text/css"&gt;
                  </pre>
                </td>
              </tr>
            </table>
          </dd>
          <dt><tt>page-footer</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This is the HTML that will go on the bottom of the page. As
              Cricket is shipped, it includes a link to the RRD Tool website.
              Tobias Oetiker, the author of RRD Tool, has respectfully asked
              frontend authors to feature a link to RRD Tool. Please take into
              account his wishes as you edit this tag.
            </p>
            <p>
              The version of <tt>page-footer</tt> in the sample-config directory
              refers to a tag called <tt>contact</tt>, which can be used to put
              sub-tree specific contact information into the bottom of the page.
              This is only meant as an example. You might choose to put
              completely different information at the bottom of the page.
            </p>
          </dd>
          <dt><tt>page-header</tt></dt>
          <dd>Default value: <i>none</i>
            <p>
              This is the HTML that will go at the top of the page, after the
              &lt;body&gt; tag, but before the rest of the user interface. As
              shipped, it illustrates how you might put a company logo on each
              page.
            </p>
          </dd>
        </dl>
      </div>

      <div id="event">
        <h3>The Event Dictionary</h3>
        <p>
          This dictionary holds information related to <i>events</i>. An event
          is some point in time which you'd like to mark on graphs so that
          later, you'll remember why it was that those graphs look the way they
          do. An event is named, just like a target or a datasource. The event
          names are used in the <a href="#view">view dictionary</a> tag called
          <tt>events</tt>. names are used in the target dictionary tag called
          <tt>events</tt>.
        </p>
        <p>Each event should have the following tags set:</p>
        <dl>
          <dt><tt>color</tt></dt>
          <dd>
            <p>
              The color of the event. This should be the name of a color in the
              <a href="#color">color dictionary</a>.
            </p>
          </dd>
          <dt><tt>date</tt></dt>
          <dd>
            <p>
              The time the event happened, which controls where on a graph the
              vertical rule appears.
            </p>
          </dd>
          <dt><tt>name</tt></dt>
          <dd>
            <p>This is the text that will show up in the legend on the graph.</p>
          </dd>
        </dl>
      </div>

      <div id="rra">
        <h3>The RRA Dictionary</h3>
        <p>
          The RRA dictionary holds parameters used by Cricket when it is setting
          up a new RRD file. These parameters control how much data RRD stores,
          and on what schedule it consolidates high resolution data into lower
          resolution data.
        </p>
        <p>
          The RRA dictionary that ships with Cricket in the sample config tree
          will rollup and retain data using the same schedule that MRTG 2.x has
          used for years. This has proven satisfactory for most users. If you
          change the polling rate from 5 minutes, this dictionary needs to be
          edited. Likewise, if you want to keep history farther back in time,
          you'll need to edit these entries.
        </p>
        <p>
          Because this table is only used when a new RRD is being created, you
          would need to delete any existing datafile, losing all of the data in
          it, before a change to the RRA dictionary takes effect.
        </p>
        <p>
          For more information on the format of these dictionary entries, read
          the RRD Tool documentation on the "create" command.
        </p>
      </div>
    </div>

    <div>
      <p>
        <a href="http://cricket.sourceforge.net">Cricket</a> version
        1.0.5, released 2004-03-28.
      </p>
      <p>
        Copyright (C) 1998-2000 Jeff Allen. Cricket is released under the
        <a href="gpl.html">GNU General Public License</a>.
      </p>
    </div>
  </body>
</html>