title: Jboss Datasource configuration for MySQL - MysqlXADataSource element
body: <p>I have been looking at several examples for configuring a datasource for MySQL in Jboss 7. All references i have seen for the  element looks like this:</p>
  
  <pre><code>&lt;driver name="com.mysql" module="com.mysql"&gt;
      &lt;driver-class&gt;com.mysql.jdbc.Driver&lt;/driver-class&gt;
      &lt;xa-datasource-class&gt;com.mysql.jdbc.jdbc2.optional.MysqlXADataSource&lt;/xa-datasource-class&gt;
  &lt;/driver&gt;
  </code></pre>
  
  <p>I know what the <code>&lt;driver-class&gt;</code> is but what exactly is the <code>&lt;xa-datasource-class&gt;</code> what is its purpose?</p>
  
  <p>When i configured a datasource on Tomcat before i did not need to specify the xa-datasource for any database. Why is it different here?</p>
  
  <p>Thanks</p>