RE: Welcome AL!

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Konrad Underkofler
>
> Welcome to the iSeries community. Given all of Joe's
> ranting about "the best business logic server",
> whatever that might be the point was lost.

Konrad, a business logic server is a machine that serves the business logic
tier.  I know that's a little simplistic, but let me be more precise: the
business logic tier processes transactions using the business rules, and
communicates with the database tier to store and retrieve data.

In most traditional n-tier designs, the business logic tier and database
tier reside on the same machine, although we've had some interesting
discussions lately about separating those two.  For example, you might have
a business logic tier that prints history data.  Some of the history is
local to the business logic machine, but older history might be offloaded
onto a cheaper, slower data archival machine.

In any event, the business logic server is specifically a machine that
processes transactions.  The difference between it and a business
application server is that the logic server doesn't need a UI, while the
application server does.

The AS/400 can play both roles - it can be the logic server in a completely
distributed environment, processing user transactions without ever
communicating directly with the user.  I have one client who uses FreeBSD as
a web serving front end to the AS/400.  IMO this is using the AS/400 purely
at its best: processing database transactions in batch using native HLL
support.

On the other hand, the AS/400 can also be an application server, either
using traditional 5250 UI (which as we know is very expensive) or through a
web interface using either RPG-CGI or via servlets using either WebSphere or
Tomcat.

Welcome to the many uses of the AS/400!

Joe