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

<chapter>
	
	<title>&adminguide;</title>
	
	<section>
	<title>Overview</title>
	<para>
	  Apache Cassandra is an open source distributed database management system.
	  It is designed to handle very large amounts of data spread out across many
	  servers. It is a NoSQL solution.
	</para>
	<para>
	  The module allows the insertion and retrieval of information from Cassandra
	  clusters. This is not a DB driver module.
	</para>
	</section>
	<section>
	<title>Dependencies</title>
	<section>
		<title>&kamailio; Modules</title>
		<para>
		The following modules must be loaded before this module:
			<itemizedlist>
			<listitem>
			<para>
				<emphasis>none</emphasis>.
			</para>
			</listitem>
			</itemizedlist>
		</para>
	</section>
	<section>
		<title>External Libraries or Applications</title>
		<para>
		  This module depends on the thrift library version 0.7.0. Please install this
		  library in order to be able to successful compile this module. You can find
		  this library at http://thrift.apache.org/
		  <itemizedlist>
		    <listitem>
		      <para>
			<emphasis>thrift 0.7.0</emphasis> - available at
			http://thrift.apache.org/
		      </para>		      
		    </listitem>
		  </itemizedlist>
		</para>
	</section>
	</section>
	<section>
	<title>Parameters</title>
	<section>
		<title><varname>host</varname> (str)</title>
		<para>
		  Host of Cassandra node.
		</para>
		<title><varname>port</varname> (int)</title>
		<para>
		  Port of Cassandra node.
		</para>
		<example>
			<title>Set <varname>host</varname> and <varname>port</varname> parameters</title>
		<programlisting format="linespecific">
...
modparam("ndb_cassandra", "host", "10.22.22.190")
modparam("ndb_cassandra", "port", 9160)
...
</programlisting>
		</example>
	</section>
	</section>

	<section>
	  <title>Functions</title>
	  <section>
	    <title>
		<function moreinfo="none">cass_insert(keyspace, column_family, key, column, value)</function>
	    </title>
	    <para>
	      Inserts the value for the given key, column, column_family and keyspace.
	      There must be an existing keyspace called 'keyspace' with a column_family
	      called 'column_family' in the targeted Cassandra node.
	    </para>
	    <para>
	      Return integer needs to be checked:
	      <itemizedlist>
		<listitem>
		  <para>ret &lt; 0, error</para>
		</listitem>
		<listitem>
		  <para>ret &gt; 0, success</para>
		  </listitem>
		</itemizedlist>
	      </para>
	    </section>
	    <section>
	      <title>
		<function moreinfo="none">cass_retrieve(keyspace, column_family, key, column, value)</function>
	      </title>
	      <para>
		Retrieves the value for the given key, column, column_family and keyspace.
		There must be an existing keyspace called 'keyspace' with a column_family
		called 'column_family' in the targeted Cassandra node.
	      </para>
	      <para>
	    <varname>value</varname> will be returned as well as a integer return code.
	  </para>
	  <para>
	    Return integer needs to be checked:
	    <itemizedlist>
	      <listitem>
		<para>
		  ret &lt; 0, error
		</para>
	      </listitem>
	      <listitem>
		<para>
		  ret &gt; 0, success
		  </para>
		</listitem>
	      </itemizedlist>
	    </para>
	  </section>

	  <example>
	    <title>Example usage</title>
	    <programlisting format="linespecific">
	      ...
    loadmodule "ndb_cassandra.so"
    # (...)
    modparam("ndb_cassandra", "host", "10.22.22.190")
    modparam("ndb_cassandra", "port", 9160)
    # (...)
    xlog("L_DBG", "Testing ndb_cassandra module.");
    # Inserting to cassandra
    $var(keyspace) = "indigital";
    $var(column_family) = "employees";
    $var(column) = "name";
    $var(val_write) = "TestMyName"; # To be written
    if (cass_insert("$var(keyspace)", "$var(column_family)", "$ru", "$var(column)", "$var(val_write)") > 0) {
       xlog("L_DBG", "ndb_cassandra. Sucess while inserting to Cassandra. val_write: \"$var(val_write)\"");
    } else {
       xlog("L_DBG", "ndb_cassandra. Error while inserting to Cassandra");
    }

    # Retrieving from cassandra
    $var(keyspace) = "indigital";
    $var(column_family) = "employees";
    $var(key) = "sip:10.22.22.110"; # Before we saved our $ru, which was 'sip:10.22.22.110'
    $var(column) = "name";
    $var(val_read) = ""; # To be read
    if (cass_retrieve("$var(keyspace)", "$var(column_family)", "$var(key)", "$var(column)", "$var(val_read)") > 0) {
       xlog("L_DBG", "ndb_cassandra. Sucess while reading from Cassandra. val_read: \"$var(val_read)\"");
    } else {
       xlog("L_DBG", "ndb_cassandra. Error while reading from Cassandra");
    }
	      ...
	    </programlisting>
	  </example>	 
	</section>
	</chapter>
