Is Bulky Session Object Better or a Bulky Stateful Sess bean better
Hi,
We are clustering on Weblogic 6.0. Currently we are debating on whether
to cache out ACL information which is very bulky in the session object
or to store it into a statefull session bean and store the handle to
that bean in the HttpSession object
I "feel" it might be preferable to bulk the Session bean than to bulk
the HttpSession object. Weblogic documentation discourages making the
HttpSession object heavy citing replication issues. But wouldnt the same
issues arise when we store a lot of information on the Session Bean.
Also do all attributes of the Session bean need to be Serializable to
support clustering.
Any help will be appreciated.
Thanks
Sameer
Sticky -- it will continue to go back until the session or the server dies.
Peace,
Cameron Purdy
Tangosol Inc.
<< Tangosol Server: How Weblogic applications are customized >>
<< Download now from http://www.tangosol.com/registration.jsp >>
"Sameer Wadkar" <[email protected]> wrote in message
news:[email protected]...
> If user x makes a call to servlet Y on Machine A where Machine A and B are
in
> cluster. If the user makes a second call to Y will the proxy webserver if
thats
> what is being used redirect the user call to machine A
> and not B for sake if laodbalancing?
>
> Sameer
> Cameron Purdy wrote:
>
> > Replication uses serialization. Serialization does not take transient
> > fields. Therefore, even when used in a stateful session bean,
replication
> > would not take transient fields.
> >
> > Peace,
> >
> > --
> > Cameron Purdy
> > Tangosol, Inc.
> > http://www.tangosol.com
> > Tangosol: How Weblogic applications are customized
> >
> > "Sameer Wadkar" <[email protected]> wrote in message
> > news:[email protected]...
> > > Cameron,
> > >
> > > One last question? If I have a stateful session bean and I have an
handle
> > to
> > > it. In a clustered environment would a transient field inside a
Stateful
> > > Session bean NOT BE replicated. I understand the situation for
HTTPSession
> > > objects. I just want to confirm if the situation is treated in
identical
> > > fashion while replicating Stateful Session Beans.
> > > If I am working in a clustered environment and a client has
established an
> > > HTTPSession with respect to my server. When the client makes repeated
> > calls to
> > > the server in the context of that session is the client request
forwarded
> > to
> > > the same server each time if there is no failover or to diff servers
in
> > the
> > > cluster to meet loadbalancing req.
> > > Also what is preferable (I am now not talking of clusteringnow : just
> > > performance issues in a single server) storing a large object in
> > HTTPSession
> > > object or
> > > putting that large object in a Stateful Session Bean and storing its
> > handle in
> > > the Session object(We need that object practically everytime a
Controller
> > > Servlet fires). Weblogic guys suggested to us that the session object
> > should be
> > > kept as small as possible to which I agree hence I thought of this
> > solution.
> > >
> > > I would appreciate your response. We are using Weblogic 6.0
> > >
> > > Regards,
> > > Sameer
> > >
> > > Cameron Purdy wrote:
> > >
> > > > Sameer,
> > > >
> > > > You are joking, right? Replicating a sh?tload of stuff across a
cluster
> > is
> > > > expensive. Cached items that can be reloaded on another server in
the
> > rare
> > > > case of failover should not be replicated, since they can be
reloaded on
> > > > another server in the rare case of failover. If you want your
> > application to
> > > > perform well, don't replicate things that you don't have to!
> > > >
> > > > Here's the math:
> > > >
> > > > - 1 in pf chance of a request having to failover, where pf should be
at
> > > > least 10,000,000
> > > > - cb is the number of bytes being replicated, and f1(cb) is the cost
of
> > > > replicating
> > > > - f2(cb) is the cost of loading the cache from the database (for
> > example)
> > > >
> > > > If f2(cb)/pf is greater than f1(cb) then you should not replicate
the
> > cache.
> > > > Generally that means that if you replicate the cache, you are
expecting
> > each
> > > > server to die after serving between one and two requests. If that is
the
> > > > case, you are really hosed to begin with.
> > > >
> > > > If you have an object stored in the HTTP session, and that object
has a
> > > > transient field, the contents of the transient field are not
replicated.
> > > > That means that you can store your cache in a transient field on an
> > object
> > > > that you store in the HTTP session, and you will not pay a
significant
> > > > replication price on it. The accessor for the cache should follow
the
> > lazy
> > > > pattern such that on failover it will reload the cache.
> > > >
> > > > For even more performance, you should implement Externalizable,
since
> > you
> > > > can improve the performance of ser/deser by a factor of 3 to 10 or
so.
> > > >
> > > > Peace,
> > > >
> > > > --
> > > > Cameron Purdy
> > > > Tangosol, Inc.
> > > > http://www.tangosol.com
> > > > Tangosol: How Weblogic applications are customized
> > > >
> > > > "Sameer Wadkar" <[email protected]> wrote in message
> > > > news:[email protected]...
> > > > > How would it matter. Both the Session Bean and The Session object
are
> > > > > destriyed whrn the user logs off.
> > > > >
> > > > > Cameron Purdy wrote:
> > > > >
> > > > > > If it is just a cache, then you need to prevent it from being
> > > > replicated.
> > > > > > Use a "transient" field or implement Externalizable on that
object
> > to
> > > > > > control serialization and avoid serializing cached objects.
> > > > > >
> > > > > > Peace,
> > > > > >
> > > > > > --
> > > > > > Cameron Purdy
> > > > > > Tangosol, Inc.
> > > > > > http://www.tangosol.com
> > > > > > Tangosol: How Weblogic applications are customized
> > > > > >
> > > > > > "Sameer Wadkar" <[email protected]> wrote in message
> > > > > > news:[email protected]...
> > > > > > > Hi,
> > > > > > >
> > > > > > > We are clustering on Weblogic 6.0. Currently we are debating
on
> > > > whether
> > > > > > > to cache out ACL information which is very bulky in the
session
> > object
> > > > > > > or to store it into a statefull session bean and store the
handle
> > to
> > > > > > > that bean in the HttpSession object
> > > > > > > I "feel" it might be preferable to bulk the Session bean than
to
> > bulk
> > > > > > > the HttpSession object. Weblogic documentation discourages
making
> > the
> > > > > > > HttpSession object heavy citing replication issues. But
wouldnt
> > the
> > > > same
> > > > > > > issues arise when we store a lot of information on the Session
> > Bean.
> > > > > > > Also do all attributes of the Session bean need to be
Serializable
> > to
> > > > > > > support clustering.
> > > > > > >
> > > > > > > Any help will be appreciated.
> > > > > > >
> > > > > > > Thanks
> > > > > > > Sameer
> > > > > > >
> > > > >
> > >
>
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private AdminSessionLocal adminSession;
+@EJB(name = "SuperAdminSession")+
private SuperAdminSessionLocal superAdminSession;
+@EJB(name = "VmSession")+
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+}+
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+try {+
InitialContext ic = new InitialContext();
return ic.lookup("java:comp/env/" sessionName);+
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+}+
+}+
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Any idea why this occurs, or how to suppress it, because it really spams our logs...
Thanks. -
I need to add the values stored in the session object into the html textbox
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i have been trying to create an edit employee details page
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1. Got employee id from HTML page.
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String Z = rs.getString(password);
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session.setAttribute("employeeid", A);
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session.setAttribute("firstname", B);
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session.setAttribute("postalcode", G);
String H = rs.getString(8);
session.setAttribute("phone", H);
String I = rs.getString(9);
session.setAttribute("mobile", I);
String J = rs.getString(10);
String url = "/EditEmpDetao;s.java";
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dispatcher.forward(request,response);
catch (Exception e)
system.out.println(e)
I do not know how to put the values stored in the session object into the html text box3. If the id is correct then pulled the record of the corresponding employee and stored it in the session object.do you really need to store this in session object?
5. Now i need to set the session values in the text field of the html form which form? in a new html/jsp page? i suggest go for a JSP
In your JSP page use JSP expression tags to put the session attributes.
it's something like : <input type='text' name='employeeid' value='<%= session.getAttribute("employeeid") %>' >and you need to generateanother servlet for saving the details/modifications to the database.
I think i m clear enough.
if you need more clarifications. just try it and then post your problem.
Diablo -
How to use a Session object in a Javascript function
I have an object that I have set in my session.
On my jsp I want to pull it out of my session and use it as a parameter for a javascript function. But I am not sure how to do that... the function call is below... I want to assign a value to ifFormat (last variable in function) But I am not sure what to use inside javascript.
<script type="text/javascript">
Calendar.setup({inputField:"f_date_dfFirstPmtDate",
button:"f_trigger_dfFirstPmtDate",
singleClick:true,
ifFormat:XXXXX});
</script>Note that javascript runs on the client side, and JSP runs on the server. JSP and the session objects are NOT available to javascript in reaction to the user.
If this function is called only when the page is first created, not when the user interacts with the page, or if you want that value to be constant with respect to the javascript, then you can do this:
<%
String someValue = (String)session.getAttribute("theAttributeName");
%>
<script type="text/javascript">
Calendar.setup({inputField:"f_date_dfFirstPmtDate",
button:"f_trigger_dfFirstPmtDate",
singleClick:true,
ifFormat:<%=someVale%>});
</script> -
How to use session object in jsp
hi all
marry christmas
can anyone plz tell me how to use session obect in jsp
rachna
Message was edited by:
rachna_arora82hi rachna,
JSP has a default(implicit) session object...... use the getSession(true) method on the session object and then going u can either get or set attributes depending on the requirement
That was in general and now with the issue u have got..... what u can do is that the u can create session for every user who logs in and when he/she tries to login again then u can probably check for the existing session object in the JSP and perform the logic as required..... any clarifications plzzzzzzz let me know
Thanks n Regards
Naveen M
Message was edited by:
Novice_inJAVA
Message was edited by:
Novice_inJAVA -
How to obtain a session object from session id
Hi all,
let say that I have a list of session ids, and I want by scheduald task to check whether the session is alive\active.
I saw that the HttpSessionContext was deprecated. (see: http://javasolution.blogspot.com/2007/08/getting-session-object-using-session-id.html)
Is there any other way to check if the session is alive?Do it the other way: let the session itself notify that it is not alive anymore.
Implement a HttpSessionListener which adds the session to list/set/map on create and removes the session from it on destroy, register it in the web.xml and run it. -
How to implement a Session Object.
Hi,
If anybody show me any example of how to implement
session object so that I can store any parameters such as user id and use it later on. And also if there is any good web site for reference about using session object.
thanksYou can use the the session.setAttribute and session.getAttribute methods.
For example let's say you would want to store a username in the session after a user has logged on:
String usrname = request.getParameter("username");
session.setAttribute("myStoredUsername", usrname);
you can then retrieve it using the get method. Remember that the entities stored inside a session object are generic objects and need to be cast to be used:
String usrname2 = (String)session.getAttribute("username");
Hope this helps
Chelman -
How to validate a session object in jsp?
Hi All,
i am facing a problem.The problem is how to validate the session object object in jsp.I have written a java script by using a defined function as setInterval and has given 5 mintues if the user is idle and will show a pop up menu before time out the session but in case of page active still this pop up menu is coming. The java script as follows.
function SetTimer(){
//How long before timeout (should be a few minutes before your server's timeout
//set timer to call function to confirm update
if(timeoutMinutes)
timerObj = setInterval("ConfirmUpdate()",60000);
function clearTimerFn(){
timerCount = 0;
clearInterval(timerObj);
//timerObj = setInterval("ConfirmUpdate()",60000);
function ConfirmUpdate(){
//Ask them to extend
if(confirm("Your session is about to expire. Press 'OK' to renew your session.")){
//load server side page if ok
var url = "ajaxSessionchecker.do?sessionvalidate=sessionvalid";
LoadXMLDoc(url);
And in jsp i am calling this js function as
<%session=request.getSession(false);
if(session.getLastAccessedTime()==60000){ %>
<script type="text/JavaScript">
clearTimerFn();
</script>
<%}else{
session.setMaxInactiveInterval(-1000);} %>
could you pls help me out?The reason for doing this is when ever i come to this user.jsp from account.jsp with a different account number this user.jsp is not refreshed and i still
see the same old user.jsp for the previous account that i naviated before. Also please let me know if there is any other approach to acheive this taskDoes refreshing the page by pushing F5 solve the problem?
If so, then the browser is caching the page, despite your attempts to stop it. -
hi,
is possible obtain the session object in a class method without send it from jsp as a parameter?you mean like this?
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest req,
HttpServletResponse res)
throws Exception {
SessionManager sm = new SessionManager(req);
....sessionmanager class
package com....;
import java.util.*;
import java.lang.reflect.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.jsp.*;
import javax.servlet.http.*;
import org.apache.log4j.*;
* <code>SessionManager</code> is a wrapper for request, response and session
* @author
public class SessionManager {
static Logger log = Logger.getLogger(SessionManager.class);
** Holds string containing the unique identifier assigned to this session
private String sessionid;
** Holds HttpSession object
private HttpSession session;
** Holds request object object - must be passed in by the calling application
private HttpServletRequest request;
** Holds response object - any application sending a response must call
** session manager
private HttpServletResponse response;
** Holds Servlet Context - useful if logging is reqd.
private ServletContext context;
* Page context.
private PageContext pctx = null;
** Constructor to initialize with a request object
public SessionManager(HttpServletRequest req) {
request = req;
session = req.getSession();
sessionid = session.getId();
** Constructor to initialize with a pagecontext object - convenient to call from jsp's
public SessionManager(PageContext pctx) {
request = (HttpServletRequest) pctx.getRequest();
response = (HttpServletResponse) pctx.getResponse();
context = pctx.getServletContext();
session = pctx.getSession();
sessionid = session.getId();
this.pctx = pctx;
** Constructor to initialize with request, response objects
public SessionManager(HttpServletRequest req, HttpServletResponse resp) {
request = req;
response = resp;
session = req.getSession();
sessionid = session.getId();
** Constructor to initialize with request, servletcontext objects
public SessionManager(HttpServletRequest req, ServletContext ctx) {
request = req;
context = ctx;
session = req.getSession();
sessionid = session.getId();
** Constructor to initialize with request, response and context objects
public SessionManager(HttpServletRequest req, HttpServletResponse resp, ServletContext ctx) {
request = req;
response = resp;
context = ctx;
session = req.getSession();
sessionid = session.getId();
** Setter and getter methods
public void setRequest(HttpServletRequest req) {
request = req;
session = req.getSession();
sessionid = session.getId();
** Setter and getter methods
public void setContext(ServletContext ctx) {
context = ctx;
** Setter and getter methods
public ServletContext getContext() {
return context;
public void createLoginSession(java.io.Serializable obj) {
if (obj == null)
log.debug("Object is null");
setAttribute("user", obj);
public void setAttribute(String key, java.io.Serializable obj) {
session.setAttribute(key, obj);
public void removeAttribute(String key) {
session.removeAttribute(key);
** Setter and getter methods
public HttpServletRequest getRequest() {
return request;
** Setter and getter methods
public HttpServletResponse getResponse() {
return response;
** Checks if either member session or guest session exists
public boolean isLoggedIn() {
if (session.getAttribute("user") != null)
return true;
else
return false;
public long getCreationTime() {
return session.getCreationTime();
** Setter and getter methods
public String getId() {
return session.getId();
public long getLastAccessedTime() {
return session.getLastAccessedTime();
public int getMaxInactiveInterval() {
return session.getMaxInactiveInterval();
** Setter and getter methods - also useful for retrieving state object(s)
public Object getAttribute(String name) {
if (session != null)
Object sObject = session.getAttribute(name);
//Log.debug("Session State for the object "+name+" is "+sObject);
return sObject;
else
return null;
** Setter and getter methods - gets enum of all stored state objects
public Enumeration getAttributeNames() {
return session.getAttributeNames();
public void invalidate() {
session.invalidate();
// Remove all object that is bound to this session
//wip : Resetting instance variable.
//This is necesary as further operations on session will
//result in illegalstateexception
session = null;
public boolean isNew() {
return session.isNew();
public void setMaxInactiveInterval(int interval) {
session.setMaxInactiveInterval(interval);
* This method returns the host url in the form "www.carclub.com".
* <p>
* The return value is compatible with default_website field of clubs DB table.
* </p>
* @return host url present as part of the http request object
public String getHostURL()
if (request == null)
return null;//No request object present, hence return null
String str = request.getServerName();
//Log.debug("--- The request URL is --- " + str);
return str;
* Flushes <code>out</code> stream.
public void flush()
throws IOException
if (pctx != null)
pctx.getOut().flush();
}
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