[ale] SASIxp System Req'ts Interpreted (was Re: [ale] New Twiki topicLinuxInGASchools)

[Jeff Hubbs]

As I mentioned earlier, they appear to run an app called SASIxp in
Gwinnett.  SASIxp appears to handle large-scale school admin stuff and,
if it's well-written, probably works very well for the whole county and
saves them a lot of admin overhead.

I went looking through their stated "System Requirements" looking for
possible Linux-ization.  Here's what I found and my supposition thereon.




"LAN Client Hardware

Microsoft® Windows® Configurations

    * Minimum: Intel® Pentium® 166, 32 MB RAM, color display, 250 MB
free hard disk space, Microsoft Windows 95, 98, NT® 4.0, Ethernet or
token ring adapter.
    * Recommended: Intel Pentium 350, 64 MB RAM, color display, 500 MB
free disk space, Windows 95, 98, 2000, or Windows NT client, Ethernet or
token ring adapter."

Ok, nothing noteworthy there - probably no need for overclocking :-)

"Macintosh® Configurations

    * Minimum: Power Mac™ 120 MHz, 48 MB RAM, color display, 250 MB free
disk space, Mac® OS 7.5, Ethernet or token ring adapter.
    * Recommended: Power Mac G3 300 MHz, 96 MB RAM, color display, 250
MB free disk space, Mac OS 7.5, OS 8, or OS 9, Ethernet or token ring
adapter."

Nothing noteworthy there either.  These two together and the fact that
no mention of browser other other software is made suggests that they
supply a client app for Win32 and another for Mac.  As far as using a
Linux client, looks like you're looking at Wine or something of that ilk
and hoping for the best.

"School Server Hardware...

Note: School server specifications listed are based on a dBase® IV
implementation. Oracle®, Microsoft SQL Server™, and IBM® DB2®
implementations are supported and require customized configurations."

Ah, this tips me off.  dBase IV was a DOS app that simply opened and
accessed data files, index files, etc. and it was possible to have those
files be on a file server and access them from more than one client at
once, at least up to the point where multiple updates started to wreck
things (I never had occasion to run dBase IV networked, so I don't
know).  My expectation is that they've written the SASIxp app to simply
open, read, and modify dBase files that are stored on a file server. 
This implies that Linux plus Samba and/or NFS could handle Win32, Mac,
or "Wined" SASIxp client apps.

Furthermore, it appears they have client apps for Win32 and Mac with
different back ends coded to talk to RDBMSses instead of just working
with dBase IV files.  If they can handle these RDBMSses, it ought to be
a fairly short hop to be able to handle MySQL or PostgreSQL.  This would
take vendor intervention unless it turned out that the calls made by the
client app for Oracle, etc. were understood and acted upon perfectly by
PostgreSQL, etc.

Reading on...

"Microsoft Windows or Mixed Windows and Macintosh Client Environment

    * Minimum: Intel Pentium 166...
    * Recommended: Intel Pentium 350...

All Macintosh Client Environment

    * Minimum: Power Mac 120 MHz...
    * Recommended: Power Mac G3 300 server..."

No special software requirements at all.  This reinforces my suspicion
that the basic SASIxp implementation is simply nothing but client apps
hitting on shared-out files.

My conclusions:

1.  A complete SASIxp implementation can be run ENTIRELY on Open Source
software (e.g., Linux, Samba) as long as the client app can be run
effectively in Wine or something similar (this opens up the door to a
LTSP implementation)

2.  If the client app absolutely must run under Win32/Mac, then
Linux/Samba/AppleTalk can probably completely handle the server
requirements while the client apps run on their native OSses.

3.  1 and 2 above presuppose that the baseline approach of using dBase
IV files to store data is utilized.  To switch to a genuine
client-server model and still use Open Source software, the client app
would have to be modified by the vendor to interoperate with Open Source
RDBMSses such as MySQL or PostgreSQL.  A server running such an RDBMS
would be used instead of a file server (although a file server might
still be used to distribute the client app).

4.  Even in the likely-worst-case scenario described in #2, significant
cost reduction may be possible by the elimination of server operating
system license costs and client access license costs associated with a
SASIxp deployment.

5.  By running the file server using Linux and Samba, steps can be taken
to maximize the server's performance by compiling the Linux kernel,
other operating system software, and server daemon software (e.g.,
Samba) for the server's specific CPU and configuring the server without
extraneous kernel code employed or unused services.  This means that
pre-existing or surplus hardware can be used whereas otherwise new
equipment might be required.  


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