Re: Linux Internet Server Project

[Jeff Licquia <jeff@licquia.org>]

On Mon, 2002-02-11 at 20:02, Tim McDonough wrote:
> We have instrumentation scattered across the US that monitors a
> variety of industrial processes. These embedded computers call our
> host PCs periodically to report status, etc. The data we collect is
> analyzed by us and among other things the results are made available
> to our customers. We want them to be able to get their reports via a
> web page which they would log in to.
> 
> The data is presently stored on several Win98 machines in an Access
> database. One machine does data collection and another uses that data
> in conjunction with some GIS functions that do routing for service
> work. The data collection could be migrated to Linux at some point.
> The GIS would need to remain in Windows.

I've been watching this discussion with some interest, as I have a (very
small) background in data acquisition.  I hope my ideas assist you in
some way.

Were this my project, I would go about it very cautiously; you don't
want to disrupt current functionality if you can avoid it.  Thus, I
would start by designing a database to hold the entire data set
currently stored in Access; if it were necessary or prudent, I would
also design a second database containing just the Web-visible data.  I
would then set up the database on the Linux server using MySQL or
PostgreSQL, set up the Web server, and test the setup with old or fake
data until it was working.

Once the site was functional with non-live data, I would write an Access
application to replicate the Access data to the Linux database server. 
Ideally, I'd copy the Access database at some point when it wasn't in
use and work off the copy.  If a second database was needed, I would
generate its data from the first Linux database, not directly from the
Access raw data.  At this point, it would be ready to give to customers.

After that worked, I would work on replacing the Access database with
the Linux one, doing the data collection directly to Linux.  If you have
control over the data collection program, you could do this by simply
changing data sources; Access can be hooked to either PostgreSQL or
MySQL.

Which database you choose depends on your needs.  Historically, MySQL
has a reputation for being fast and uniquely suited to Web work, but it
could also be less reliable.  PostgreSQL had the exact opposite
reputation: slow but solid.  This has been changing in recent years, as
PostgreSQL has become much faster while MySQL has gained features that
make it more reliable (record locks, transactions, and so on).  I would
look at both and decide which is best for you.

As for distribution, I tend to be partial to Debian, but in reality any
of the Linux distributions would probably work.  Being in Springfield, I
would probably suggest Red Hat or SuSE, as I recall that these seem to
be a bit more favored in my old home town, and you'll likely find lots
of helpful people to help you with their quirks.


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