Stateful Session Bean Initialization (EJB 3.0)

Hi all!
In EJB 2.1 the initialization was with create (args) methods. NOw, how is it exploited? Create methods are no more there and there must be a way to send parameters to the stateful session bean when it is newly created...isn't it?
Thank you!

There is no pre-defined equivalent of a create method in EJB 3.0. If you want to initialize a
stateful session bean, just define a business method that the client should use as an initialization
method.

Similar Messages

How to intantiate Stateful session bean in EJB 3 ?

In EJB 2.x, to instantiate a Stateful Session bean the process was:
1. Lookup Home object
2. call create(args) method on Home, that in turn would call corresponding ejbCreate(args) on the bean implementation.
Now, in EJB 3, there is no concept of Home interaface, How can I instantiate a stateful session bean with some initialization parameters.
Thanks

Just the spec. NetBeans should only be providing the ability to add an ejbCreate method if the bean exposes a Local or Remote 2.x view.
Each lookup or injection of a stateful session bean results in a new bean instance. As long as you call your methods to populate the additional
state right after first acquiring the stateful session bean reference it will work.
--ken

How create EJB 2.1 Stateful Session Bean in a EJB 3.0 Session Bean

Hi All,
We have been developing on EJB 2.1. We are now adding a module on EJB 3.0.
How can we "create" a stateful session bean with create method signature similar to create(String id)?
We have tried
// this is the remote interface
@EJB AddressBean abean;
But not working
Any help will be appreciated.

There is no explicit create() call for EJB 3.0 session beans. It doesn't really matter though
since you can accomplish the same thing by defining your own business method to act
as an initializer for whatever state you'd like. E.g.
@Remote
public interface FooInterface {
public void initialize(String id);
// ... other business methods
@EJB FooInterface fooRef;
fooRef.initialize("foo");
--ken

Creating multiple stateful session beans from a java client. (EJB 3.0)

I'm having difficulties with the following:
To access the ShoppingCartBean, I have to put the following annotation in my standalone java client:
@EJB
private static ShoppingCartRemote shoppingCartBean;
The static must be there, thus only one ShoppingCartBean will exist within my java client. But as the ShoppingCartBean is a stateful session bean, I want to be able to get different beans of the same type.
What is the correct way to do this in EJB 3.0?

Great question. Because Home interfaces have been removed for the EJB 3.0 simplified
API, stateful session bean creation happens as a side-effect of injection. However, the
same is true of EJB 3.0 business interface lookups. The easiest way to create additional
stateful session beans is to lookup the same dependency that was declared via your
@EJB annotation.
E.g.,
// Assuming the declaring class is pkg1.ShoppingCartClient.java
InitialContext ic = new InitialContext();
ShoppingCartRemote scr1 = (ShoppingCartRemote)
ic.lookup("java:comp/env/pkg1.ShoppingCartClient/shoppingCartBean");
Note that the name relative to java:comp/env is the default associated with your
@EJB annotation since the name() attribute wasn't used. Alternatively, you
could have used :
@EJB(name="scb") private static ShoppingCartRemote shoppingCartBean;
InitialContext ic = new InitialContext();
ShoppingCartRemote scr1 = (ShoppingCartRemote) ic.lookup("java:comp/env/scb");
Yet another alternative is to declare the @EJB at the class-level. This just defines
the dependency without any injection, which is fine if you want to create a bunch of
them via lookup anyway.
@EJB(name="scb", beanInterface=ShoppingCartRemote.class)
public class .... {

Initialize a stateful session bean from another

Hi,
I am trying to create and initialize a stateful session bean from another stateful session bean. The code is as follows
This method belongs to DefaultSessionBean where it creates the AdminSessionBean based on few checks and returns it to the client.
    public AdminSession getAdminSession() throws UnknownException, WarningException {
        checkSessionUser("getAdminSession");
        if (isAdmin()) {
            AdminSession adminSession;
            try {
                final Context context = IToolsUtil.getInitialContext();
                adminSession = (AdminSession)context.lookup("AdminSession");
                System.out.println("Successfully created the adminsession bean");
            } catch (NamingException ne) {
                ne.printStackTrace();
                throw new UnknownException (new CatalogHelper("ITOOLS_100019", new Object[]{"Admin", ne.getMessage()}));
            System.out.println("adminsession will be returned");
            return adminSession;
        } else {
            throw new WarningException (new CatalogHelper("ITOOLS_000042", sessionUser.getUserhandle()));
    }Another method in DefaultSessionBean, creates its local interface and returns it.
    public DefaultSessionLocal getDefaultSessionLocal() {
        DefaultSessionLocal dsl = (DefaultSessionLocal)context.getBusinessObject(DefaultSessionLocal.class);
        System.out.println("local created.");
        return dsl;
    }Client call initialize method of the AdminSessionBean which is mentioned below:
    public void initialize(DefaultSession ds) throws WarningException, UnknownException {
        this.ds = ds.getDefaultSessionLocal();
        this.rfl = ReadFieldList.getInstance();
        this.fm = new FinderMethods();
    }The client code where it gets the adminSession and initializes is
   public static AdminSession getAdminSession(DefaultSession ds) throws ViewException {
        AdminSession as;
        try {
            as = ds.getAdminSession();
            System.out.println("got admin session");
        } catch (WarningException we) {
             we.printStackTrace();
            throw new ViewException(we.getCatalogHelper());
        } catch (UnknownException ue) {
            ue.printStackTrace();
            throw new ViewException(ue.getCatalogHelper());
        } catch (OracleRemoteException ore) {
            ore.printStackTrace();
            throw new ViewException(new CatalogHelper("ITOOLS_050003", ore.getMessage()));
        // Initialize Admin Session
        try {
            System.out.println("before getting it.");
            as.initialize(ds);
            System.out.println("adminsession is initialized");
        } catch (WarningException we) {
            as.remove();
            as = null;
            throw new ViewException(we.getCatalogHelper());
        } catch (UnknownException ue) {
            as.remove();
            as = null;
            throw new ViewException(ue.getCatalogHelper());
        } catch (OracleRemoteException ore) {
            as.remove();
            as = null;
            throw new ViewException(new CatalogHelper("ITOOLS_050003", ore.getMessage()));
        System.out.println("got admin session");
        return as;
    }Apart from this I am using OC4J 10.1.3.1 tool test my application.
When I am calling initialize method of the AdminSession I am getting the following error.
06/10/24 12:26:08 Entered
06/10/24 12:26:08 got default session
06/10/24 12:26:08 Successfully created the adminsession bean
06/10/24 12:26:08 adminsession will be returned
06/10/24 12:26:08 got admin session
06/10/24 12:26:08 before getting it.
2006-10-24 12:26:08.156 WARNING J2EE RMI-00009 Exception returned by remote server: {0}
06/10/24 12:26:08 com.itools.vs.view.exception.ViewException
06/10/24 12:26:08      at com.itools.vs.view.util.ViewUtil.getAdminSession(ViewUtil.java:71)
06/10/24 12:26:08      at com.itools.vs.view.backing.Admin.CreateUser.submit_action(CreateUser.java:182)
06/10/24 12:26:08      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
06/10/24 12:26:08      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
06/10/24 12:26:08      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
06/10/24 12:26:08      at java.lang.reflect.Method.invoke(Method.java:585)
06/10/24 12:26:08      at com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:146)
06/10/24 12:26:08      at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:92)
06/10/24 12:26:08      at org.ajax4jsf.framework.ajax.AjaxActionComponent.broadcast(AjaxActionComponent.java:88)
06/10/24 12:26:08      at org.ajax4jsf.framework.ajax.AjaxViewRoot.processEvents(AjaxViewRoot.java:274)
06/10/24 12:26:08      at org.ajax4jsf.framework.ajax.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:250)
06/10/24 12:26:08      at org.ajax4jsf.framework.ajax.AjaxViewRoot.processApplication(AjaxViewRoot.java:405)
06/10/24 12:26:08      at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:95)
06/10/24 12:26:08      at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
06/10/24 12:26:08      at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:110)
06/10/24 12:26:08      at javax.faces.webapp.FacesServlet.service(FacesServlet.java:213)
06/10/24 12:26:08      at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:64)
06/10/24 12:26:08      at org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:67)
06/10/24 12:26:08      at org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:223)
06/10/24 12:26:08      at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:621)
06/10/24 12:26:08      at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:368)
06/10/24 12:26:08      at com.evermind.server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:866)
06/10/24 12:26:08      at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:448)
06/10/24 12:26:08      at com.evermind.server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler.java:216)
06/10/24 12:26:08      at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:117)
06/10/24 12:26:08      at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:110)
06/10/24 12:26:08      at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:260)
06/10/24 12:26:08      at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:239)
06/10/24 12:26:08      at oracle.oc4j.network.ServerSocketAcceptHandler.access$700(ServerSocketAcceptHandler.java:34)
06/10/24 12:26:08      at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:880)
06/10/24 12:26:08      at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303)
06/10/24 12:26:08      at java.lang.Thread.run(Thread.java:595)
06/10/24 12:26:08 ITOOLS_050003: Failed to get Admin Session.
Exception is "Error marshalling objects, Not Serializable: java.io.NotSerializableException: DefaultSession_RemoteProxy_6nein01; nested exception is:
     java.io.NotSerializableException: DefaultSession_RemoteProxy_6nein01".
[b/

Your remote client passes a DefaultSession to AdminSession.initialize(..). This DefaultSession has to be a remote type. In your client, how does it get DefaultSession?
Did your client look up DefaultSession, and have it return a (sessionContext.getBusinessObject(DefaultSession.class))? If so, it should work.

EJB 3.0 Stateful session bean shared between Servlet's

Hello
I have a bit of a noob question regarding Stateful sessions beans.
I am wanting to know if there is a way that I can share an instance of a session bean between multiple HttpServlet instances?
I am sending XML messages from a mobile J2ME application, there will be several http POST's made from the mobile client to the server. I would like these multiple POST's to be passed from the handling servlet instance to the same uniquely identified single stateful session bean instance (i can then @Remove the stateful bean when I have finished my several requests).
I would greatly appreciate any tips anyone could give me.

If not, your only option is to maintain the
association yourself by creating a unique id for
each
conversation and storing that id along with the SFSB
reference in the ServletContext. Then you'll
need to pass the id in along with each invocation to
retrieve the appropriate SFSB reference.Thanks for your reply.
Will I always be presented with the same ServletContext instance? Even if the time between requests might be many minutes? Where can I learn more about how to use the ServletContext?
Thanks!

SAME EJB 3.0 Stateful Session bean for different JSP sessions returned

Forum,
I have a strange problem utilizing stateful session beans. Please note, that I am using jdeveloper for the following:
1) Here is a basic stateful session bean:
@Stateful(name = "DemoClass")
public class DemoClassBean implements DemoClass,
           DemoClassLocal, SessionSynchronization {
      public static int id=0;
      public DemoClassBean() {
      id++;
      public int getId() {
         return id;
      //... other methods
}2) This bean is accessed from a JSP for testing purpose, I am copying only the script used in JSP:
<%
   DemoClass bean = null;
   try {
      bean = (DemoClass) ((new javax.naming.InitialContext()).
                   lookup("DemoClass "));
      System.out.println("ID=" + bean.getId() );
      } catch (javax.naming.NamingException e) {
         // TODO
%>If this page is addressed by different clients, from different browsers, the same bean is returned.
Here is what I see in the logs:
ID=1
ID=1
ID=1
The same problem is being observed when this session bean is accessed from a JSF Backing bean.
What could be wrong? Is this a bug in oc4j / jdeveloper (version 10.1.3.3.0)?
Edited by: smw000000001 on Nov 17, 2008 10:52 AM

Hi,
The code for stateful is perfectly fine and working in a normal way. The way you are trying to implement the stateful session bean in your application is wrong.
think of binding the stateful session bean with HttpSession object.
So that you will get a unique stateful session bean object.

[EJB] Stateful session bean--- strange error

hi guys,
here s my problem. i m trying to developp a stateful session bean with two ejbcreate method. one with parameters ( ejbcreate(int val)) and another one without (ejbcreate()).
The client can call ejbcreate without any pbs. everything s allright.
but when i try to get a remote access to the bean via a
MY_BEAN.create(5); then i got an error saying :
FAILED TO FIND METHOD FOR HASH ......
i dont understand cuz i checked my files many times and the two methods are implemented and declared in the home interface.
what should i do ?
please.
tery

Hi Tery,
You are in the wrong forum. This forum is for the Sun Java Studio Creator.
Cheers :-)!!!

EJB 2.0 STATEFUL SESSION BEANS -- ejbPassivate or ejbActivate is not called

Hi,
am using Oracle Jdevloper 9i. When i use Stateful Session beans the ejbPassivate or ejbActivated methods are not being called. What is the reason?

Hi Arun,
The decision of when to passivate a stateful session bean is up to a particular vendor's implementation. Typically each vendor will have some configuration that controls this decision, but it's certainly common for passivation to not take place for a given workload. Your best bet is to look at the Oracle documentation to see how the container makes its passivation decision.
--ken

Call existing stateful session bean in different servlets

hello,
we are implementing a shopping cart for our online dvd store in netbeans 5.5.1 and ejb 3.0.
for that we use a stateful session bean, which is created when a user is logging in for connecting the user-entity to the bean.
after logging in, the list servlet, which displays a list of all available dvds, is shown. after clicking the "add to shopping cart" button, the cart servlet with a list of all added dvds is shown. in this servlet we want to reactivate the existing stateful session bean. is this possible? and when it's possible, how is it possible? ;)
our sessionbean with initialize() method:
@Stateful
public class CartBean implements Cart {
    UserEntity user;
    List<DVDEntity> contents;
    public void initialize(UserEntity user){
        System.out.println("Warenkorb erstellt");
        this.user = user;
        contents = new ArrayList<DVDEntity>();
}thx!
Edited by: licherpremium on Nov 8, 2007 6:35 AM

hello,
we are implementing a shopping cart for our online dvd store in netbeans 5.5.1 and ejb 3.0.
for that we use a stateful session bean, which is created when a user is logging in for connecting the user-entity to the bean.
after logging in, the list servlet, which displays a list of all available dvds, is shown. after clicking the "add to shopping cart" button, the cart servlet with a list of all added dvds is shown. in this servlet we want to reactivate the existing stateful session bean. is this possible? and when it's possible, how is it possible? ;)
our sessionbean with initialize() method:
@Stateful
public class CartBean implements Cart {
    UserEntity user;
    List<DVDEntity> contents;
    public void initialize(UserEntity user){
        System.out.println("Warenkorb erstellt");
        this.user = user;
        contents = new ArrayList<DVDEntity>();
}thx!
Edited by: licherpremium on Nov 8, 2007 6:35 AM

Howto call the @Remove method of a stateful session bean after JSF page ...

I use EJB3, JPA, JSF in my web application. There are 2 database tables: Teacher and Student. A teacher can have many (or none) students and a student can have at most 1 teacher.
I have a JSF page to print the teacher info and all his students' info. I don't want to load the students' info eagerly because there's another JSF page I need to display the teacher info only. So I have a stateful session bean to retrieve the teacher info and all his students' info. The persistence context in that stateful session bean has the type of PersistenceContextType.EXTENDED. The reason I choose a stateful session bean and an extended persistence context is that I want to write something like this without facing the lazy initialization exception:
<h:dataTable value="#{backingBean.teacher.students}" var="student">
<h:outputText value="${student.name}"/>
</h:dataTable>Because my session bean is stateful, I have a method with the @Remove annotation. This method is empty because I don't want to persist anything to the database.
Now, my question is: How can I make the @Remove method of my stateful session bean be called automatically when my JSF page finishes being rendered?

Philip Petersen wrote:
I have a few questions concerning the EJB remove method.
1) What is the purpose of calling the remove method on stateless session
bean?There isn't one.
>
2) What action does the container take when this method is called?It checks that you were allowed to call remove (a security check) and then
just returns.
>
3) What happens to the stateless session bean if you do not call the remove
method?Nothing
>
4) Is it a good practice to call the remove method, or should the remove
method be avoided in the case of stateless session beans?
Personally, I never do it.
-- Rob
>
>
Thanks in advance for any insight that you may provide.
Phil--
AVAILABLE NOW!: Building J2EE Applications & BEA WebLogic Server
by Michael Girdley, Rob Woollen, and Sandra Emerson
http://learnWebLogic.com
[att1.html]

Stateful session bean destroying instance variables?

I'm trying to use a stateful session bean as some kind of login controller and to maintain the login id and access level across JSPs and HTMLs so that once logged in, all the JSPs can obtain the login name of the current user (String) and his access level (int).
I use the login.jsp to login and it successfully reports logging in with the correct access level retrieved from database. However, if I go to another JSP (testlogin.jsp), these 2 EJB instance variables are always destroyed and set to null and 0 when I access them again.
What am I missing that my stateful session bean is not saving these instance variables? Do I need to put them in some serializable value objects (create a help VO class?)
I suspected that on different JSP, I call the MemberControllerHome.create() method, it creates a new instance or something but if I don't use the create method how do I get a handle to MemberController at all?
MemberControllerBean.java
public class MemberControllerBean implements SessionBean {
     //initialize in ejbCreate.
     private MemberHome memberHome;
     SessionContext context;
     //Member currentLogin;
     //Current Login
     private String loginID;
     private int accessLevel;
     // Constructor
     public MemberControllerBean() {}
...some code in between...
public void login(String id, String password){
          try{
               Member member = null;
               member = memberHome.findByPrimaryKey(id);
               if(member.getMPassword().equals(password)){
                    this.loginID = member.getMID();
                    this.accessLevel = member.getMAccessLevel();
               else{
                    throw new EJBException("Login failed. Invalid member ID and/or password.");
          } catch (FinderException ex) {
               throw new EJBException("Login failed. Invalid member ID and/or password.");
     public void logout(){
          this.loginID = null;
          this.accessLevel = 4;
     public String getLoginID(){
          return this.loginID;
     public int getLoginAccessLevel(){
          return this.accessLevel;
login.jsp
String mID = request.getParameter("mID");
String mPassword = request.getParameter("mPassword");
out.println("20:" + mID + ":" + mPassword);
if(mID != null && mPassword != null){
     out.println("22:" + mID + ":" + mPassword);
     try{
          InitialContext ic = new InitialContext();
          MemberControllerHome home = (MemberControllerHome) ic.lookup("java:comp/env/ejb/MemberController");
          MemberController mc = home.create();
          out.println("26:Logging in as " + mID + " with " + mPassword);
          mc.login(mID, mPassword);
          out.println("28:" + mc.getLoginID() + "logged in successfully at level " +
               mc.getLoginAccessLevel() + ".");
     } catch (NamingException ex) {
          out.println("java:comp/env/ejb/MemberController not found.");
     } catch (EJBException ex) {
          out.println(ex.getMessage());
     } catch (Exception ex) {
          out.println(ex.getMessage());
testlogin.jsp
<%
try{
     InitialContext ic = new InitialContext();
     MemberControllerHome home = (MemberControllerHome) ic.lookup("java:comp/env/ejb/MemberController");
     MemberController mc = home.create();
     out.println("You are logged in as <b>" + mc.getLoginID() +
          "</b> at level <b>" + mc.getLoginAccessLevel() + "</b>.");
} catch (NamingException ex) {
     out.println("java:comp/env/ejb/MemberController not found.");
} catch (EJBException ex) {
     out.println(ex.getMessage());
} catch (Exception ex) {
     out.println(ex.getMessage());
%>

The key to the problem is that in testlogin.jsp a new stateful session bean is created. The new bean instance of course doesn't know the log-in information you stored in the old session bean. That is why the method returns null and 0 when called.
There are couple of ways to solve the issue. The easiest solution is to store the bean instance created in Login.jsp in the jsp's implicit HttpSession object. Because login.jsp and testlogin.jsp share the same session, the bean instance can be easily stored and retrieved.
Here is the code you need to have:
1. in login.jsp
session.setAttribute("MemberControllerBeanInstance", mc);
2. in testlogin.jsp
MemberController mc =
(MemberController) session.getAttribute("MemberControllerBeanInstance");
Hope it helps.

Calling Enity Bean's business methods from a session bean in EJB 3.0 specif

Hello everybody,
Happy to be a member with you in this forum.
This is my first participation in this forum.
I have some problem to start with EJB 3.0 specification, I have created an entity bean with some business methods that access a mysql datbase, then i want to create a stateful session bean to provide the client an interface to consume business methods in Enity be
Please can someone you help me with an example

@Vladimir Pavlov
I did not understand what you are trying to convey...
Whenever an attribute of this bean is modified we want to access that latest value.... Is there any way to know, when the attribute is modified? Just with get/set we can not know, when it is modified... am i right?
We want to achieve this without modifying the existing source code of the EJB....
@ Ivo Simeonov
As of my knowledge, to use interceptors we need to modify the EJB source code, but we do not want to touch the source code....
All this has to be achieved dynamically when the application is deployed in the production.... is it possible???

Accessing the same stateful session bean from multiple clients in a clustered environment

I am trying to access the same stateful session bean from multiple
          clients. I also want this bean to have failover support so we want to
          deploy it in a cluster. The following description is how we have tried
          to solve this problem, but it does not seem to be working. Any
          insight would be greatly appreciated!
          I have set up a cluster of three servers. I deployed a stateful
          session bean with in memory replication across the cluster. A client
          obtains a reference to an instance of one of these beans to handle a
          request. Subsequent requests will have to use the same bean and could
          come from various clients. So after using the bean the first client
          stores the handle to the bean (actually the replica aware stub) to be
          used by other clients to be able to obtain the bean. When another
          client retrieves the handle gets the replica aware stub and makes a
          call to the bean the request seems to unpredictably go to any of the
          three servers rather than the primary server hosting that bean. If the
          call goes to the primary server everything seems to work fine the
          session data is available and it gets backed up on the secondary
          server. If it happens to go to the secondary server a bean that has
          the correct session data services the request but gives the error
          <Failed to update the secondary copy of a stateful session bean from
          home:ejb20-statefulSession-TraderHome>. Then any subsequent requests
          to the primary server will not reflect changes made on the secondary
          and vice versa. If the request happens to go to the third server that
          is not hosting an instance of that bean then the client receives an
          error that the bean was not available. From my understanding I thought
          the replica aware stub would know which server is the primary host for
          that bean and send the request there.
          Thanks in advance,
          Justin


          If 'allow-concurrent-call' does exactly what you need, then you don't have a problem,
          do you?
          Except of course if you switch ejb containers. Oh well.
          Mike
          "FBenvadi" <[email protected]> wrote:
          >I've got the same problem.
          >I understand from you that concurrent access to a stateful session bean
          >is
          >not allowed but there is a
          >token is weblogic-ejb-jar.xml that is called 'allow-concurrent-call'
          >that
          >does exactly what I need.
          >What you mean 'you'll get a surprise when you go to production' ?
          >I need to understand becouse I can still change the design.
          >Thanks Francesco
          >[email protected]
          >
          >"Mike Reiche" <[email protected]> wrote in message
          >news:[email protected]...
          >>
          >> Get the fix immediately from BEA and test it. It would be a shame to
          >wait
          >until
          >> December only to get a fix - that doesn't work.
          >>
          >> As for stateful session bean use - just remember that concurrent access
          >to
          >a stateful
          >> session bean is not allowed. Things will work fine until you go to
          >production
          >> and encounter some real load - then you will get a surprise.
          >>
          >> Mike
          >>
          >> [email protected] (Justin Meyer) wrote:
          >> >I just heard back from WebLogic Tech Support and they have confirmed
          >> >that this is a bug. Here is their reply:
          >> >
          >> >There is some problem in failover of stateful session beans when its
          >> >run from a java client.However, it is fixed now.
          >> >
          >> >The fix will be in SP2 which will be out by december.
          >> >
          >> >
          >> >Mike,
          >> >Thanks for your reply. I do infact believe we are correctly using
          >a
          >> >stateful session bean however it may have been misleading from my
          >> >description of the problem. We are not accessing the bean
          >> >concurrently from 2 different clients. The second client will only
          >> >come into play if the first client fails. In this case we want to
          >be
          >> >able to reacquire the handle to our stateful session bean and call
          >it
          >> >from the secondary client.
          >> >
          >> >
          >> >Justin
          >> >
          >> >"Mike Reiche" <[email protected]> wrote in message
          >news:<[email protected]>...
          >> >> You should be using an entity bean, not a stateful session bean
          >for
          >> >this application.
          >> >>
          >> >> A stateful session bean is intended to be keep state (stateful)
          >for
          >> >the duration
          >> >> of a client's session (session).
          >> >>
          >> >> It is not meant to be shared by different clients - in fact, if
          >you
          >> >attempt to
          >> >> access the same stateful session bean concurrently - it will throw
          >> >an exception.
          >> >>
          >> >> We did your little trick (storing/retrieving handle) with a stateful
          >> >session bean
          >> >> on WLS 5.1 - and it did work properly - not as you describe. Our
          >sfsb's
          >> >were not
          >> >> replicated as yours are.
          >> >>
          >> >> Mike
          >> >>
          >> >> [email protected] (Justin Meyer) wrote:
          >> >> >I am trying to access the same stateful session bean from multiple
          >> >> >clients. I also want this bean to have failover support so we want
          >> >to
          >> >> >deploy it in a cluster. The following description is how we have
          >tried
          >> >> >to solve this problem, but it does not seem to be working. Any
          >> >> >insight would be greatly appreciated!
          >> >> >
          >> >> >I have set up a cluster of three servers. I deployed a stateful
          >> >> >session bean with in memory replication across the cluster. A client
          >> >> >obtains a reference to an instance of one of these beans to handle
          >> >a
          >> >> >request. Subsequent requests will have to use the same bean and
          >could
          >> >> >come from various clients. So after using the bean the first client
          >> >> >stores the handle to the bean (actually the replica aware stub)
          >to
          >> >be
          >> >> >used by other clients to be able to obtain the bean. When another
          >> >> >client retrieves the handle gets the replica aware stub and makes
          >> >a
          >> >> >call to the bean the request seems to unpredictably go to any of
          >the
          >> >> >three servers rather than the primary server hosting that bean.
          >If
          >> >the
          >> >> >call goes to the primary server everything seems to work fine the
          >> >> >session data is available and it gets backed up on the secondary
          >> >> >server. If it happens to go to the secondary server a bean that
          >has
          >> >> >the correct session data services the request but gives the error
          >> >> ><Failed to update the secondary copy of a stateful session bean
          >from
          >> >> >home:ejb20-statefulSession-TraderHome>. Then any subsequent requests
          >> >> >to the primary server will not reflect changes made on the secondary
          >> >> >and vice versa. If the request happens to go to the third server
          >that
          >> >> >is not hosting an instance of that bean then the client receives
          >an
          >> >> >error that the bean was not available. From my understanding I
          >thought
          >> >> >the replica aware stub would know which server is the primary host
          >> >for
          >> >> >that bean and send the request there.
          >> >> >
          >> >> >Thanks in advance,
          >> >> >Justin
          >>
          >
          >

Error in updating secondary stateful session bean

          Hi all,
          I have set up a cluster of 2 managed servers with WebLogic 6.1. I have a
          stateful session bean and several stateless session beans. the stateful
          session bean keeps user info and limited cached objects, all are
          serializable. it seems working fine, even after killing any one of the
          servers, as long as one is alive. a java application client creates a
          stateful session bean first, then calls stateless session beans with the
          remote interface of the stateful bean as a method parameter. No problem
          when stateful session bean is created. However, each stateless bean method
          generates the following error message if I turn the debug on (level 64). No
          exception stack traces, and all methods execute successfully.
          <Error> <EJB> <Failed to update the secondary copy of a stateful session
          bean from home:clientsession>
          I wonder what causes the error, and why it tries to update the stateful
          session bean. in all stateless session beans, only read into the stateful
          bean.
          Thank you,
          Fujin


This has been fixed in WLS 6.1 SP2.
          jagdip Talla wrote:
          > Hi Fujin,
          > please let me know, if u were able to solve the problem..
          >
          > hi guys,
          > appreciate if you could give me some clues
          > how to solve this problem ?
          >
          > i hv 2 WLS instances in a cluster,
          > when one server instance is shut down, i keep getting these errors ?
          > is it normal ?
          > <Feb 19, 2002 2:57:53 PM SGT> <Error> <EJB> <Failed to update the secondary copy of a stateful session bean from home:ejb/xyzrel1_2/xxxxHome>
          >
          > appreciate if u can let me know, if u could solve it..?
          >
          > thanks n regads
          > jagdip
          Rajesh Mirchandani
          Developer Relations Engineer
          BEA Support

Stateful Session Bean Initialization (EJB 3.0)

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