tinou,
its the age old argument of stateful vs. stateless.
with most ejb vendors, there is some form of
passivation mechanism which is triggered when
the number of [active] stateful bean instances
exceeds a certain (usually configurable) limit.
so the memory usage will not go overboard when
the number of users shoots up. (this passivation
could be done with entity beans as well)
note that there will be some overhead when
passivated beans (session or entity) have to
activated again by reading from secondary
storage ... but on modern systems, this will be
relatively unnoticeable.
to preempt your next question, quite a few
ejb vendors also provide for failovers for
stateful session beans (I know Borland and
BEA do)
-krish
----- Original Message -----
From: Tinou Bao <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, April 26, 2001 3:13 PM
Subject: ejb - distributed components
> hello ejb gurus,
>
> ejbs are meant to be distributed components that handle security,
> transaction, lifecycle management, etc. for you...my question is if you
know
> that your component will not be a distributed component, but may still
need
> other services that the container provides, does it make sense to model
your
> component as an ejb? take, for example, the pet store demo in the
> blueprint. the shopping cart is model as a stateful session bean. why
> would this need to be a distributed component? if pets.com architected
> their system this way and get 100,000 online shoppers the system would
have
> 100,000 stateful session beans floating around. seems to me that this
would
> not be very scalable or at least harder to scale. another question i have
> is with the popular session facade pattern does it make sense to make the
> entity beans entity beans.
>
> any and all comments are appreciated,
> tinou
>
>
===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the
body
> of the message "signoff EJB-INTEREST". For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
>
>
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
