[TriLUG] Question about webapp design philosophy

[Jon Carnes]

What your looking at is a CGI that is a front-end parser.  The CGI
passes the "data" (the info in the URL) onto an other server called an
application server.  The application server sits inside the firewall on
another machine - or several other machines.

"MyEbayItemsBiddingOn" is simply one of the sub-programs written on the
application server.

Most web-serving from large companies is done in this manner.  The
front-end webserver is really more of a router/load balancer for http
requests.  It forwards any complex requests onto a group of application
servers.  The application servers do the heavy lifting.  They figure out
the information and graphics that you need to see and then spit out a
stream of HTML that gets the job done.

The webserver then simply forwards on the html that was created by the
appservers.

The philosophy behind it is that machines are cheap, and by splitting
out the tasks, you can serve a lot more folks a lot faster.  Plus
Application servers let you do some amazing things that just aren't
possible with raw HTML. As an example, most database lookup's are done
via appservers.  Also, any script or program you write can made
available via html using appservers.

The appserver also has access to corporate processes and data that you
don't want exposed via an ordinary webserver (especially if its an IIS
webserver!).  Having the appserver communicate via a proprietary
connection to the webserver adds a level of security while still
allowing you to make those sensitive services and data available via the
web.

Take care - Jon Carnes

On Sun, 2002-09-08 at 19:32, Mike Helms wrote:
> Hi everyone,
> 
> I've been studying ebay (as best as one can study ebay just by looking at
> it), and it appears that many of the pages in ebay are generated from the
> same "page" on their webserver.  There is a variable passed through the URL
> that acts, in effect, like a "command" to the page, telling it what we are
> trying to do.  When I go to the My Ebay page, the command is
> MyEbayItemsBiddingOn.  When I view an item, it is ViewItem.
> 
> This makes sense, as it means there wouldn't be dozens, if not hundreds or
> even thousands of separate pages to maintain in the website.  In effect, you
> could have one tremendously large page that would actually comprise the
> entire website.  If nothing else, this would save on repetition.
> 
> Is there a reason not to do this?  I'm laying the groundwork now for a new
> webapp that I'm going to build, and this has certainly given me cause to
> rethink my design philosophy.
> 
> Cheers,
> -- Mike Helms
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