SFSB being removed - jsf-2

Question

I'm using JBoss6.1.Final, JSF 2.0 (Mojarra), Weld CDI, MyFaces CODI 1.0.5 (for view-access-scoped)
I'm using something like the Gateway Pattern from Real World Java EE Patterns Rethinking Best Practices (unfortunately I don't have it with me, so I may have screwed something up here). Basically, the application allows a user to go into "edit mode" and edit a List of people (create, edit, remove) maintained in a #ViewAccessScoped backing bean with an extended persistence context and then click a "save" command link that flushes all their changes to the database. At first I was having a problem with ViewExpiredExceptions (if the browser was idle past the session-timeout period and then further requests are performed), but I added some jQuery to make a get request to a servlet that keeps the session alive (called 10 seconds before session-timeout). This seems to be working but now I have another problem, the backing bean is also a SFSB and after some idle time, it is being removed resulting in the following error message being logged (and all ajax rendered data disappears) when I attempt to perform more edits ...
13:06:22,063 SEVERE [javax.enterprise.resource.webcontainer.jsf.context] javax.el.ELException: /index.xhtml #27,81 rendered="#{!conversationBean.editMode}": javax.ejb.NoSuchEJBException: Could not find stateful bean: 43h1h2f-9c7qkb-h34t0f34-1-h34teo9p-de
Any ideas on how I could prevent SFSB removal or at least handle it more gracefully?
Here's my backing bean:
package com.ray.named;
import java.io.Serializable;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.ejb.EJBTransactionRolledbackException;
import javax.ejb.Stateful;
import javax.ejb.TransactionAttribute;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceContextType;
import org.apache.myfaces.extensions.cdi.core.api.scope.conversation.ViewAccessScoped;
import com.ray.model.Person;
#Named
#Stateful
#ViewAccessScoped
#TransactionAttribute(javax.ejb.TransactionAttributeType.NEVER)
public class ConversationBean implements Serializable {
private static final long serialVersionUID = 1L;
//properties
private List<Person> people;
private String name;
private Boolean editMode;
#PersistenceContext(type=PersistenceContextType.EXTENDED)
private EntityManager em;
#PostConstruct
public void init() {
people = em.createNamedQuery("Person.findAll", Person.class).getResultList();
setEditMode(false);
}
//event listeners
public void beginEdits() {
setEditMode(true);
}
public void addPerson() {
Person p = new Person(name);
em.persist(p);
people.add(p);
name = null;
}
public void removePerson(Person p) {
people.remove(people.indexOf(p));
em.remove(p);
}
//this method flushes the persistence context to the database
#TransactionAttribute(javax.ejb.TransactionAttributeType.REQUIRES_NEW)
public void saveEdits() {
setEditMode(false);
}
//getters/setters
public List<Person> getPeople() {
return people;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Boolean getEditMode() {
return editMode;
}
public void setEditMode(Boolean editMode) {
this.editMode = editMode;
}
}
Here's the Person entity bean:
package com.ray.model;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Version;
#Entity
#NamedQueries({
#NamedQuery(name="Person.findAll",
query="SELECT p FROM Person p")
})
public class Person {
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private Integer id;
private String name;
#Version
private int version;
public Person() { }
public Person(String name) {
setName(name);
}
public boolean equals(Object o) {
if (!(o instanceof Person)) {
return false;
}
return id == ((Person)o).id;
}
//getters/setters
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public int getVersion() {
return version;
}
public void setVersion(int version) {
this.version = version;
}
}
Here's the view:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:head>
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script>
$(document).ready(function() {
setInterval(function() {
$.get("#{request.contextPath}/poll");
}, #{(session.maxInactiveInterval - 10) * 1000});
});
</script>
<title>Conversation Test</title>
</h:head>
<h:body>
<h:form>
<h:commandLink value="Begin Edits" rendered="#{!conversationBean.editMode}">
<f:ajax render="#form" listener="#{conversationBean.beginEdits}"/>
</h:commandLink>
<h:commandLink value="Save" rendered="#{conversationBean.editMode}">
<f:ajax render="#form" listener="#{conversationBean.saveEdits}"/>
</h:commandLink>
<h:dataTable id="peopleTable" value="#{conversationBean.people}" var="person">
<h:column>
<f:facet name="header">Name</f:facet>
<h:panelGroup>
<h:inputText value="#{person.name}" disabled="#{!conversationBean.editMode}">
<f:ajax/>
</h:inputText>
<h:commandLink value="X" disabled="#{!conversationBean.editMode}">
<f:ajax render="#form" listener="#{conversationBean.removePerson(person)}"/>
</h:commandLink>
</h:panelGroup>
</h:column>
</h:dataTable>
<h:panelGrid columns="2">
<h:outputLabel for="name">Name:</h:outputLabel>
<h:inputText id="name" value="#{conversationBean.name}" disabled="#{!conversationBean.editMode}"/>
</h:panelGrid>
<h:commandButton value="Add" disabled="#{!conversationBean.editMode}">
<f:ajax execute="#form" render="#form" listener="#{conversationBean.addPerson}"/>
</h:commandButton>
</h:form>
</h:body>
</html>
Here's a servlet used to keep the session alive (called by jQuery ajax get request 10 seconds before session expires):
package com.ray.web;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class PollServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void init() throws ServletException {
}
public String getServletInfo() {
return null;
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
request.getSession(); //Keep session alive
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
}
public void destroy() {
}
}

Answer 1

Any ideas on how I could prevent SFSB removal or at least handle it
more gracefully?
To investigate further I would recommend to take a look at the EJB lifecycle hooks for passivation and add some debug output there.
Should that be the source of the problem you will be able to configure / deactivate passivation - but scalability might come up as an issue.
Honestly, this scenario seems quite uncommon to me. In general I would expect requests / conversations / sessions to be working more or less in the default boundaries - should you find yourself writing code that circumvents this can it be that you are better off with a RESTful / stateless approach...?
Please update the question with further information if available.

Answer 2

I suppose you have already solved your problem. Otherwise, this JBoss wiki page should be helpful (also for future readers...).
https://community.jboss.org/wiki/Ejb3DisableSfsbPassivation
Cheers,
Luigi