Configuring Tomcat session time-out
By default the session time-out is set to 30 minutes.
To change the Tomcat session time-out, edit the $TOMCAT_HOME/conf/web.xml and change the values into the session section:
<!-- You can set the default session timeout (in minutes) for all newly -->
<!-- created sessions by modifying the value below. -->
<session-config>
<session-timeout>30</session-timeout>
</session-config>