Duan, Nick wrote:
The initial posting sounds like an EJB question instead of one that is
Tomcat related. Tomcat is considered a web application server and it
uses session objects (HttpSession) to represent user sessions. It
doesn't handle EJBs at this point. Session beans are exclusive terms
for EJB servers (e.g. JBoss, WebLogic, WebSphere, etc.)
If you want to determine memory usage of session objects in tomcat, the
answer will depend on the content/size of HttpSession and the number of
concurrent users.
If you really mean session beans in EJB, you need to differentiate the
types of session beans. There are two types of session beans, stateless
and stateful (as of EJB spec 2.1). Stateless session beans can be
pooled, so the memory usage for them would be the size of a bean object
times the size of the pool. Stateful session beans can't be pooled, so
their memory usage would be the size of the bean times the number of
concurrent users.
The size of any java object is usually defined by its size on the heap,
determined by its instance data members. The number of methods does not
matter.
ND
-----Original Message-----
From: Frank W. Zammetti [mailto:[EMAIL PROTECTED]
Sent: Saturday, January 14, 2006 1:35 PM
To: Tomcat Users List
Subject: Re: Size of session bean
That's an interesting question... looking at the code I wrote in Java
Web Parts for the getSessionSize() method, I'm only taking into
consideration the fields of the objects in session. I think this is OK
because IIRC, when an object is serialized, only the non-transient
values are considered. The methods don't factor into it because you
aren't serializing the class definition, just the state of the object.
If anyone knows differently I'd like to hear about it, but I believe how
that method works yields an accurate result.
If you want to see how I've done it, check out:
http://javawebparts.sourceforge.net
If you look at the javadocs, in the session package, there is a class
called SessionSize that is used to get the size of a session object.
You can grab the code and see how it's done, or just use it if that's
your ultimate goal :)
Frank
Robert Palmer wrote:
When calculating the size of a session bean to determine memory usage,
what should be included and how is this done? Do the number of methods
matter? The size of the code? Just the variables? I've read much about
limiting the size of the session information but not how to do it. I
have some fairly large classes in session context but they don't store
very much.
Thanks.
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I was referring to tomcat and everything that is in session context. (ie
jsp:useBean with scope=session).
Thanks for the answers.
