The timeout of the web session of Analytics can be modified in the web.xml configuration file, located in :
<Analytics Folder>\WEB-INF\web.xml
The parameter to configure is in the session-timeout in the session-config block, which might be commented :
<!-- <session-config> -->
<!-- <session-timeout>1</session-timeout> -->
<!-- </session-config> -->
Example :
<session-config>
<session-timeout>10</session-timeout>
</session-config>
The timeout is in minutes.
When this block is commented out, the timeout of the Application Server applies. For example, on Tomcat it's 30minutes by default.