Re: Client / Server

[Vernon Hamberg <hambergv@xxxxxxxxxxxxxx>]

Uffda, Lance

At 04:21 PM 12/1/1997 -0500, you wrote:
>        I am in charge of developing a client / server system.   I would
>like all the input this group can supply me.  I am in the very early stages
>(picking software, middleware, etc....) of development.  
>
>      I am looking to basically rewrite much of or all of our existing
>system.  The goal is to supply the users with a GUI interface, a more
>efficient interface (drop down menus, push buttons, etc...), and a tool
>which will provide our programmers easier / faster development /
>maintenance.  The upgrade of our AS/400 will be to a Risc 620 machine. We
>currently have a novell network on version 3.12, we are upgrading to version
>4.11 within the next couple of months.   By the time we implement this all
>users will be Windows '95 (assuming that is the way to go).  We have one
>particular group using an NT server, which could also be available to me.
>We code in COBOL, and use a lot of Opnqryf.  We support approximately 75
>users who are active interactively, but also have a large volume of batch
>reports.   
>        
>       Please let me know any insight regarding software, middleware,
>connectivity, networks, etc....  I am starting from scratch and need help.

First, an opinion that will not sell real well, but I believe it: GUI is
_not_ usually more efficient than character-based for heads-down data
entry. Not even for programming, in my experience. Mouse usage is
'eye-driven'—you have to see where you're putting the cursor. But watch a
good green-screen entry person—they hardly look at the screen at all. It's
a little like playing a piano concerto by clicking on the notes on the screen!

OTOH, mouses are great for graphical things—makes sense, they're a
graphical paradigm. So, my suggestion is, make sure you have keyboard
navigation equivalents of, e.g., the 'hook' key. And 'field exit'.

JMHO

Lots of options:

GUI interface (not necessarily more efficient)

        1.      Visual Basic—Windows only for the client—may not be an issue

        2.      Seagull—converts your green-screens to GUI, allows you to 
customize
                and rearrange your screens further, mapping to various GUI 
components
                and even reorganizing the screens

                Leaves your AS/400 apps intact

                No processing on PC—presentation only

                Same tool as IBM used to generate Graphical Access screens 
(Client
                Access 95/NT)

        3.      Visual Age for Java—verrrry nice tool for creating Java apps, 
much
                better than VB in generating underlying code

                Apps will run on anything, applets can run in any Web browser

                Uses TCP/IP sockets for communication to AS/400—you don't need 
to
                know too many details

                Downside may be learning curve—but sounds like you'll face that,
                no matter which of these (or other) options you choose

                Has built-in versioning for change management

                Comes shipped with all new RISC boxes and upgrades to v4r?

                AS/400 Toolkit for Java provides tools for working with native 
AS/400
                objects in Java

Communications

        1.      Client Access—has a good ODBC driver, _usually_ works very well 
on
                Win 95/NT

        2.      TCP/IP—native on both AS/400 and 95/NT

                Runs over any physical network infrastructure you may have

                Client Access installation over TCP/IP is a dream

                Requires planning for you overall network, to utilize 
TCP/IP—latest
                Novell supports it almost native, right, anyone?

        3.      Native IPX—now on AS/400

                Client Access can use—I haven't done it myself—and install 
effort ought
                to be about the same as TCP/IP

        4.      Forget about SNA Server, no matter what NT people might say—no 
need
                for any benefits it may've provided 3 years ago

                Direct TCP/IP (or whatever) to AS/400 is much easier to 
maintain than
                through SNA Server

        5.      Try to avoid routers at all costs—like the NS routers that come 
with
                Client Access

Better development environment

        1.      I've found that the PC 5250 emulation that comes with Client 
Access
                gives a lot of the benefits of GUI environments (cut & paste, 
macros,
                etc.) that are touted for various Windows-based development 
products
                (like ALDON's FlexEdit or IBM's CODE/400). The combination of 
SEU and
                the emulation gives me all the power I need, with full access 
to help
                text, prompts, etc., that the other products don't always have.

                FlexEdit, although a nice-looking product, gives you nothing 
for CL
                prompts or help text—at least last time I looked. And I've seen 
nothing
                that'll cause me to leave SDA or RLU for designing screens and 
reports.
                (Yes, RLU is pretty lame, but there's not much else better since
                PrintCoder is no longer available, IMO.)

        2.      For AS/400 change management, there are a number of products. 
We've
                been using ALDON's CMS (Change Management System), although for
                reaons of staying current with IBM, I might recommend IBM's ADM
                (Application Development Manager), which looks and works just 
like
                PDM

        3.      The Java thing again—VA for Java Enterprise Edition (the one 
bundled
                with new AS/400) has change management built in

                In addition, Java classes can be distributed from a central 
server—
                like your NT box—distribution of changes is almost eliminated 
as an
                issue

Other issues

        1.      Start thinking object orientation—Java will be standard in 
OS/400
                from v4r2

        2.      Think about various multi-tier designs for client/server— 1) 
presentation,
                mostly, at the client 2) business rules, validations, etc., at 
some middle
                server (like your NT box) 3) database, SQL, etc., on the AS/400 
(or
                some other backend DBMS, if necessary)

        3.      Learn SQL

I'd love to be in on this one! Sounds like fun!

HTH

Vernon Hamberg
Systems Software Programmer
Old Republic National Title Insurance Company
400 Second Avenue South
Minneapolis, MN  55401-2499
(612) 371-1111 x480


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