Remote Data Access 1

[Monsores]

Hello Everybody,
Does anyone know a way of remotely accessing a database with a clipper application?
We have already tried Advantage Database Server (

http://www.advantagedatabase.com)

with a Linux server, but it needs samba to Work. What we need is to access a database in one network usin a clipper aplication in another network. The problem is that the only communication between the two networks is Internet.
We are also going to try Mediator (

http://www.otc.pl),

which makes a clipper program access an Oracle database. We would like to have other solutions to test intead of having to choose "the only one".

Thanks,
Marcelo

 

[aker]

Hi.

Probably not the solution you were looking for, but have you considered using Terminal Server (Win2000) and running everything on one central server.

Just a thought.
Regards.

 

[Monsores]

Thanks for your sugestion, but there will be many people accessing the system and it also handles very big dbfs, so I'm not sure about the performance.

The Advantage Database representative told us that it wouldn't work without Samba on a Linux server, but we got it. The Advantage Database can be accessed through an RDD, and togheter with another small utility it can open remote databases via IP. As it's a Database Server, even with Clipper it isn't slow. We will be testing the performance for some time, bit untill now everything is fine.

Thanks again,
Regards.

Marcelo

 

[ccc555]

Hello Marcelo,

Keep us inform on your progress, I would like to find out more about Samba & Linux. Can you let me know what hardware you are using and the various software needed to run remotely. Many Thanks

regards,
Richard

 

[ccc555]

Hello Marcelo,

Care to share your experience?

Thanks

 

[Michael42]

>> many people accessing the system and it also handles very big dbfs

If terminal Server is configured properly with sufficient hardware it can handle many situations.

The size of the datbase does not matter to Terminal Server as it just sends screen type updates using a thin client. The app (and database) run on the server locally.

I've used WinFrame\MetaFrame\Terminal Server with hundreds of concurrent users. It helps to use the MetaFrame load balancing software if you get above 30 concurrent users though.

Hope this helps,
Michael

 

[ccc555]

Thanks Michael,

I am looking for other altenatives besides MS, interested to know more about Samba & Linux, or did I read wrongly.

regards,
Richard

 

[fenarro]

Hi,


I have been using

http://www.goodtechsys.com

telnet server for windows 98 o 2000 and work great, 10 simultanius users .


Regards

Fernando

 

[Michael42]

fenarro,

Are you using Clipper with Telnet? If not what are your apps written in?

Thanks for the info,
Michael

 

[Monsores]

Hi people,
Sorry for not anwering this thread on time, but i had some problems and the project was delayed for some time, but on january I concluded it and it's working very well.
Now i have the following on the server side: Conectiva Linux 8 (a South American version of Linux) with the Advantage Database Server running over IP. It is a database server wich manages the DBF files, so it wasn't necessary to do nothing with our DBFs (just link them to the ADS).
After it they can be accessed via Delphi and many other languages just adding a little component to the project while creating it. Once compiled nothing else is necessary.
To work with Clipper programs, it is necessary to chance two code lines in each PRG that handles DBF files and add a lib to the linker script. After compiled, all the calls to DBF files will be redirected to a program that must be running on the client. This program will talk via UDP/IP to the Server on Linux.
It could also be done using Samba, but our objective was to allow connections via Internet Service Providers anywhere, so we had to use IP. A 256Kb Internet link was sufficient, because just the necessary records travel through the link (instead of the entire DBF when running the own Clipper DNFNTX database driver). The best of all is that now we can easily use not only Clipper, but also Delphi and PHP.
ADS doesn't have all the resources an Oracle solution will have, but it does everything Clipper do with a DBF file and eliminates the problems with NTX/CDX files too. It also has a transaction control that lets the server do a rollback/rollforward to eliminate data corruption in case of problems with the server.

Sorry for the big message.

Regards,
Marcelo