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<!-- Module User's Guide -->

<chapter xmlns:xi="http://www.w3.org/2001/XInclude">

    <title>&adminguide;</title>

    <section>
        <title>Overview</title>
		<para>
			The module provides the ability to send commands to statsd
			(you can use InfluxDB too) with different types of information.
			It provides native integration with statsd (https://github.com/etsy/statsd/)
			and graphite (http://graphite.wikidot.com/).
		</para>
		<para>
			The module does not have any special dependency, it does a direct
			socket connection to Graphite.
		</para>
    </section>

    <section>
        <title>Parameters</title>
        <section id="statsd.p.ip">
            <title><varname>ip</varname>(string)</title>
            <para>
            Statsd server IP address.
            </para>
            <para>
            Defaults to 127.0.0.1
            </para>
            <example>
                <title>Set ip parameter</title>
                <programlisting format="linespecific">
...
modparam("statsd", "ip", "127.0.0.1")
...
                </programlisting>
            </example>
        </section>

        <section id="statsd.p.port">
            <title><varname>port</varname>(string)</title>
            <para>
            Statsd server port number
            </para>
            <para>
            Defaults to 8125
            </para>
            <example>
                <title>Set port parameter</title>
                <programlisting format="linespecific">
...
modparam("statsd", "port", "8125")
...
                </programlisting>
            </example>
        </section>
    </section>

    <section>
        <title>Functions</title>
        <section id="statsd.f.statsd_set">
            <title>
                <function moreinfo="none">statsd_set(key, value)</function>
            </title>
            <para>
                Sets count the number of unique values passed to a key.
            </para>
            <para>
                If this method is called multiple times with the same userid in the same sample period, that userid will only be counted once.
            </para>
            <para>
                This function can be used in ALL ROUTES.
            </para>
            <example>
                <title><function>statsd_set</function> usage</title>
                <programlisting format="linespecific">
...
failure_route[tryagain] {
...
    statsd_set("customerFailure", 1);
...
}
...
                </programlisting>
            </example>
        </section>

        <section id="statsd.f.statsd_gauge">
            <title>
                <function moreinfo="none">statsd_gauge(key, value)</function>
            </title>
            <para>
                Gauges are a constant data type. They are not subject to averaging
		and they don't change unless you change them. That is, once you set
		a gauge value, it will be a flat line on the graph until you change it again.
            </para>
            <para>
                Gauges are useful for things that are already averaged, or don't need to reset periodically
            </para>
            <para>
                This function can be used in ALL ROUTES.
            </para>
            <para>
                The statsd server collects gauges under the stats.gauges prefix.
            </para>
            <example>
                <title><function>statsd_gauge</function> usage</title>
                <programlisting format="linespecific">
...
route [gauge_method]{
    statsd_gauge("method"+$rm, "+1");
    statsd_gauge("customer_credit"+$var(customer),"$var(customer_credit)");
}
...
                </programlisting>
            </example>
        </section>

        <section id="statsd.f.statsd_histogram">
            <title>
                <function moreinfo="none">statsd_histogram(key, value)</function>
            </title>
            <para>
		    The histograms are a measure of time, but they are calculated at the server side.
		    As the data exported by the client is the same, this is just an alias for the Timer type.
            </para>
            <para>
                This function can be used in ALL ROUTES.
            </para>
            <para>
                The statsd server collects histograms under the stats.histograms prefix.
            </para>
            <example>
                <title><function>statsd_histogram</function> usage</title>
                <programlisting format="linespecific">
...
    statsd_histogram("latency", 1000);
...
                </programlisting>
            </example>
        </section>
        <section id="statsd.f.statsd_start">
            <title>
                <function moreinfo="none">statsd_start(key)</function>
            </title>
            <para>
		statsd_start set an avp with the key name, and when
		statsd_stop(key) is used, the module will send statsd the difference in
		milliseconds. This is useful to know the time of a SQL query, or how much time your replies take.
            </para>
            <para>
                This function can be used in all routes.
            </para>
            <para>
                The statsd server collects all timers under the stats.timers prefix
		and will calculate the lower bound, mean, 90th percentile, upper bound, and count of each
		timer for each period (by the time it can be seen in graphite, that's usually per minute).
            </para>
            <example>
                <title><function>statsd_start</function> usage</title>
                <programlisting format="linespecific">
...
statsd_start("long_mysql_query");
sql_query("ca", "select sleep(0.2)", "ra");
statsd_stop("long_mysql_query");
...
                </programlisting>
            </example>
        </section>


        <section id="statsd.f.statsd_stop">
            <title>
                <function moreinfo="none">statsd_stop(key)</function>
            </title>
            <para>
                statsd_stop(key) get the avp string with the key and calculate the
		difference from the start time. When finished the milliseconds used will be sent to statsd.
            </para>
            <para>
                This function can be used in all routes.
            </para>
            <example>
                <title><function>statsd_stop</function> usage</title>
                <programlisting format="linespecific">
...
statsd_start("long_mysql_query");
sql_query("ca", "select sleep(0.2)", "ra");
statsd_stop("long_mysql_query");
...
                </programlisting>
            </example>
        </section>

        <section id="statsd.f.statsd_incr">
            <title>
                <function moreinfo="none">statsd_incr(key)</function>
            </title>
            <para>
            Increment a statsd counter
            </para>
            <para>
                This function can be used in all routes.
            </para>
            <example>
                <title><function>statsd_incr</function> usage</title>
                <programlisting format="linespecific">
...
if(geoip_match("$si", "src")){
    statsd_incr("country."+$(gip(src=>cc)));
}
...
                </programlisting>
            </example>
        </section>

        <section id="statsd.f.statsd_decr">
            <title>
                <function moreinfo="none">statsd_decr(key)</function>
            </title>
            <para>
                Decrement a counter
            </para>
            <para>
                This function can be used in all routes.
            </para>
            <example>
                <title><function>statsd_decr</function> usage</title>
                <programlisting format="linespecific">
...
if (t_check_status("408")) {
    statsd_decr("kamailio.successfulCalls");
    statsd_incr("kamailio.reply.timeout");
}
...
                </programlisting>
            </example>
        </section>
    </section>
</chapter>

