An app Running Over a WAN (LeasedLine/VSAT)

[benasumwa]

Hi All

(bborissov/Mike Lewis: thanks for your post on "Migration to SQL". The Thread disappeared from the list and I got confused. I did not answer back. Anyway I am utilizing your helpful tips, nonetheless)

I just had another issue with my foxpro app (EXE) running over a WAN with majorly leased lines. I would need some suggestions on how to make sure It's fast and that data intergrity is preserved.

(These sides of the earth-Africa band width seems to be very
expensive, so people operate on low measures!)

Do I need some special settings
on the sever with the fox tables?

Is operating without the DBC going to be disastrous?

Helpful hints will be much acknowledged.

Thanks in advance

Benson
Kenya, Africa

 

[DSummZZZ]

The data integrity will be preserved as long as the connection is maintained while any updates are taking place.
No, you won't need any special settings on the server for the tables, and no, operating without a DBC won't be disasterous.
My company has several apps running ove a WAN without DBC's.

That said, expect the apps to be real slow. Especially if you have tables of any significant size.

You may be better off running a COM server on the server where the tables are, and making record query/update requests to the COM server which will then retrieve or write data to the local tables.


-Dave Summers-

Even more Fox stuff at:

http://www.davesummers.net/foxprolinks.htm

 

[Mike Lewis]

Hi Benson,

I agree with everything Dave said, especially the point about it being slow. This is why people go to client/server. If there's any chance that you could do that, you'll find it much more satisfactory.

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

My Visual FoxPro site: www.ml-consult.co.uk

 

[benasumwa]

Hi

Thanks Mike/Dave for your nice contributions. I think I have to stop thinking the old way and utilize the new technologies in favor of fast applications; whatever the
infrastructure!

Dave:

You are talking about a COM server, please if you do not mind, just explain how it works and may be drop just a few lines of examples to help me proceed. The app is a payroll system which is supposed to run in locations connected via leased lines and one on VSAT. Most tables are static with only three being active (at least at endmonth)

?

Benson

 

[GriffMG]

You could try a remote access approach such as Terminal Server, Citrix, PcAnywhere, VNC or any one of about a hundred alternatives.

In the first instance - a 'get you running' approach if you like - this has to worth thinking about.

Martin

Regards

Griff
Keep [Smile]ing

 

[craigber]

The COM server solution will solve some speed issues, but could still cause problems with data corruption, lost data, etc. You could still go the COM route by using Queued Components in COM+ to help solve some of that, but client/server is still a better solution.

Craig Berntson
MCSD, Visual FoxPro MVP,

http://www.craigberntson.com

Author, CrysDev: A Developer's Guide to Integrating Crystal Reports"

 

[DSummZZZ]

My thought on a COM server, is build an app running on a server which at the request of a client would read or write to a table which it opened locally.
The client could use Winsock to connect.
It could push a string out the port which would either contain a request to read a record, or a record to be written. The server would either send back a record or a reply on the status of the written record.

But, you would have to rework the functionality quite a bit to get that sort of a scenario to work. It wouldn't be a simple matter of just using the tables.
It would be a rather drastic change to the whole system.
Probably not what you wanted to do.

-Dave Summers-

Even more Fox stuff at:

http://www.davesummers.net/foxprolinks.htm

 

[benasumwa]

Hi

Thanks all for your posts.

Dave:

>> Probably not what you wanted to do.

I think I will slowly start on client/server until
i am though. Slow but sure it will work.


Thanks again
Benson

 

[tondi]

When using Remote Access as suggested in this thread, is it reommended to run the EXE locally on remote same as LAN or WAN workstation? My app has a scheduler that creates and uses temp files for each user and will not work if the temp files are created and used on the server by another user.

 

[Mike Lewis]

Tondu,

is it reommended to run the EXE locally on remote same as LAN or WAN workstation?

Yes. You'll get much better performance if you run the EXE from a local hard drive. The trade-off is that it will take a little effort to ensure that users always have the most up-to-date version of the EXE.

The best way to handle that is to always store temp files in the user's own temporary directory -- the one returned by SYS(2023).

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

My Visual FoxPro site: www.ml-consult.co.uk

 

[tondi]

Thanks Mike