title: How do I make the session data serializable
body: <p>Previously we have implemented sticky session. </p>
  
  <p>Here's the link on our environment: <a href="https://stackoverflow.com/questions/7430570/sticky-session-in-apache-doesnt-work">Sticky Session in apache doesn&#39;t work</a></p>
  
  <p>Our next task is to implement session replication. </p>
  
  <p>We are current using tomcat example, <code>cart.jsp</code> to demonstrate this behavior. </p>
  
  <p>It is said that all session attribute must implement java.io.serializable.</p>
  
  <p>Do you have any tips on where to implement it? We are following this tutorial closely. </p>
  
  <p>tomcat.apache.org/tomcat-6.0-doc/cluster-howto.html</p>