Re: Thinking out loud about a new RPG web framework

["Aaron Bartell" <aaronbartell@xxxxxxxxx>]

> By having a connection for every user session you may run into a
scalability problem since you require the user to log out to regain the
resources allocated to that connection.

I would be curious to know how many users you could support on say an entry
level 520 with 4GB of RAM, because the same issue you are proposing is
present in applications that are written in 100% JSF apps too where the
controllers are set to type "session", correct?

Here's a question: Let's say we had an entry level 520 with 10,000 users on
it using 5250 screens.  I am guessing OS/400 appropriately pages RPG program
instances out to disk when it needs to free up memory for more active jobs,
correct?  So in theory you could support 10,000 users though the swapping of
memory for disk (and vice versa) would make for some slow responses, but
would still work, and you could then just buy more processing power to
address the situation.

I am not trying to promote poor application infrastructure design, but more
trying to find a balance of leveraging RPG/OS400/DB2 features to build apps
faster while still having it be scalable.

Aaron Bartell
http://mowyourlawn.com

On Fri, Jun 6, 2008 at 8:08 AM, Thorbjørn Ravn Andersen <
thunderaxiom@xxxxxxxxx> wrote:

> Joe Pluta skrev  den 06-06-2008 14:37:
> > Which is why I say create a single connection at the beginning of the
> > session and use it throughout.  You need connection pooling when you
> > have a stateless architecture that requires reconnection for every
> request.
> >
> By having a connection for every user session you may run into a
> scalability problem since you require the user to log out to regain the
> resources allocated to that connection.
>
> By properly using a pool for connections you can have long session
> timeouts and short idle times for connection timeouts allowing you to
> serve more users on the same hardware.
>
> This naturally requires that the backend calls are stateless - all
> needed information is passed from the session object - which you must do
> anyway since this is for web users.
>
> --
>   Thorbjørn
>
> --
> This is the Web Enabling the AS400 / iSeries (WEB400) mailing list
> To post a message email: WEB400@xxxxxxxxxxxx
> To subscribe, unsubscribe, or change list options,
> visit: http://lists.midrange.com/mailman/listinfo/web400
> or email: WEB400-request@xxxxxxxxxxxx
> Before posting, please take a moment to review the archives
> at http://archive.midrange.com/web400.