struts-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Zhang, Larry \(L.\)" <lzhan...@ford.com>
Subject RE: Session size
Date Thu, 27 May 2004 16:13:07 GMT
In my case I have to keep the List in the session level instead of application level since
different user will have different list of employees.

-----Original Message-----
From: Riyad Kalla [mailto:rsk@email.arizona.edu]
Sent: Thursday, May 27, 2004 11:53 AM
To: Struts Users Mailing List
Subject: Re: Session size


Mike,
Good suggestions. I was dealing with something like this recently and decided 
that for me, adding caching at the DAO level:

e.g. List userList = UserDAO.getAllUsers();

would offer the biggest performance benefit since it would be:

(a) application wide, instead of per session
(b) returned Lists are 4-byte pointers to the actual list object cached in the 
DAO
(c) The DAO itself handles all manipulation of those types, so it knows when 
to invalid its own cache (on inserts/updates/removes)


What do people think about this strategy? (Before I spend a week implementing 
it :)

Best,
Riyad

On Thursday 27 May 2004 08:49 am, Mike Zatko wrote:
> I personally think its too big. Large amounts of data like that should
> be put in request scope so that it gets flushed out of memory right
> away. If you need the data to be persistent through the user's session
> lifetime, mabye try serializing it to a database. Of course, different
> situations call for different solutions. Also, I would try and replace
> your Vector with a non-synchronized Collection like an ArrayList or
> LinkedList unless you have some sort of mutlithreaded access to this
> collection.
>
> Riyad Kalla wrote:
> >Larry,
> >Good question. I am curious what others think about this situation as
> > well.
> >
> >On Thursday 27 May 2004 08:24 am, Zhang, Larry (L.) wrote:
> >>It is apparent true that if the session size is big, the performance will
> >>be negatively affected. The question is that how to actively control the
> >>size of session.
> >>
> >>Let's discuss this question:
> >>
> >>I have a page which displays all the subordinates of a manager, for some
> >>reasons I want to create a List or a Vector containing all the
> >> subordinates and put this List or Vector to the session. Each element in
> >> the List or Vector is a Java object, Employee( each Employee object has
> >> 200 String attributes, among which 5 are needed to be displayed on the
> >> screen)
> >>
> >>A picture of this situation is:
> >>
> >>				Vector allSubordinates = new Vector();
> >>					allSubordinates.add(Employee1);
> >>					allSubordinates.add(Employee2);
> >>					.......
> >>
> >>					allSubordinates.add(Employee1000);
> >>
> >>
> >>session.setAttribute("allSubordinates",allSubordinates);
> >>
> >>Do you think this actually makes the session very big?
> >>
> >>
> >>Then what will be the improvement of the following? Instead of add all
> >> the employee objects, we create a very small object called
> >> DisplayObject, which just contains the 5 attributes required on the
> >> screen.
> >>
> >>				Vector allSubordinates = new Vector();
> >>					allSubordinates.add(DisplayObject1);
> >>					allSubordinates.add(DisplayObject2);
> >>					.......
> >>
> >>					allSubordinates.add(DisplayObject1000);
> >>
> >>
> >>session.setAttribute("allSubordinates",allSubordinates);
> >>
> >>Your sharing of opinion is appreciated!
> >>
> >>Thanks.
> >>
> >>Larry
> >>
> >>
> >>
> >>---------------------------------------------------------------------
> >>To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
> >>For additional commands, e-mail: user-help@struts.apache.org
> >
> >---------------------------------------------------------------------
> >To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
> >For additional commands, e-mail: user-help@struts.apache.org

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
For additional commands, e-mail: user-help@struts.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
For additional commands, e-mail: user-help@struts.apache.org


Mime
View raw message