[fpc-pascal]Databases and FPC

A.J. Venter ajventer at direqlearn.org
Tue May 6 12:56:10 CEST 2003


Thanks for your valuable insights Rainer.
> 
> Yes and no. - More NO. You can write some kind of "Middleware" which runs on
> the MySQL Machine and uses a UNIX-Socket instead of a true network connection
> and talks to small daemons on the workstations, too. So you can setup the SQL
> server to only accept local connections and nobody will be able to access
> MySQL from an external machine, because...
> a.) no connections are accepted at all
> b.) nobody knows username/password because it cannot be sniffed on the LAN.
> So you have the benefit of SQL, too.
> 
> 
> | | What other suggestions can you make ?
> | It is vital that the database be frequently updated on disk because an
> | internet cafe could lose a lot of money if a user who simply resets his
> | thinclient workstation every few minutes never actually loses time.
> 
> An what about monitoring the T.C. from the server side and locking the
> customer out when he is doing such things? There are many ways to detect such
> situations!
What you say here would normally be true, but not in this case. The
system runs on thin-clients, all the processes etc. appear to be
runnning on the localhost therefore. What you have here is best thought
off as one machine with a lot of monitors, keyboards and mice attached.
So host based security is useless.

Of course one could use an additional server, but this system was
primarilly developed for poor african schools, they run their labs as
icafe's after school to pay for their internet connectivity. It is a
vital sustainability product. These people have litle or no money, most
of the labs are paid for by sponsors. The reason the code is GPL'd is
exactly that - we put it into poor schools, we have no interest in the
rest of the icafe market so we give it to the world, in return for code
contributions.

But these labs are paid for mostly by sponsors, if we need to add
another server machine (e.g. a machine with disks) we would need to
start cutting corners on other hardware etc. I am still thinking of the
best approach to this problem, your idea of a daemon that maintains the
data, and writes it out periodically sounds very good btw, despite the
overhead of doing so. 
The point is just, there is no networking in the traditional sense of
the word here. By the time the applications start running, they think
they are running on the server.

A.J.
-- 
Story of my life: "Semper in excretum, set alta variant"
A.J. Venter
DireqLearn Linux Guru




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