VB Front end dll loses connection to back end SQL server db after an hour 
Author Message
 VB Front end dll loses connection to back end SQL server db after an hour

I have a web application consisting of front end .htm files, a front
end Visual Basic 6.0 .dll, and a back end SQL Server 7.0 database. The
.dll file contains functions and web class subroutines, and acts as an
interface between the front end .htm files, and the back end database,
by means of a data environment (.dsr) component.
After the initial installation of the .dll (via a cab file),
connectivity between the web server and sql server is fine. Users can
enter their userid/password, and these parameters are then passed to
the .dll and queried against the database which results in a
successful login.
However, after an hour or so, users can no longer login. Database
connectivity appears to be lost, and remains lost until the servers
are rebooted, or the .dll file is reinstalled.
This problem only occurs when a firewall is in place between the web
server and sql server, so it could simply be a firewall configuration
issue. Alternatively, has anyone experienced problems when trying to
connect through a firewall, by means of a data environment, or
experienced anything of this nature?

Any info would be very welcome!!

David



Tue, 06 Apr 2004 19:26:37 GMT  
 VB Front end dll loses connection to back end SQL server db after an hour

Quote:

> I have a web application consisting of front end .htm files, a front
> end Visual Basic 6.0 .dll, and a back end SQL Server 7.0 database. The
> .dll file contains functions and web class subroutines, and acts as an
> interface between the front end .htm files, and the back end database,
> by means of a data environment (.dsr) component.
> After the initial installation of the .dll (via a cab file),
> connectivity between the web server and sql server is fine. Users can
> enter their userid/password, and these parameters are then passed to
> the .dll and queried against the database which results in a
> successful login.
> However, after an hour or so, users can no longer login. Database
> connectivity appears to be lost, and remains lost until the servers
> are rebooted, or the .dll file is reinstalled.
> This problem only occurs when a firewall is in place between the web
> server and sql server, so it could simply be a firewall configuration
> issue. Alternatively, has anyone experienced problems when trying to
> connect through a firewall, by means of a data environment, or
> experienced anything of this nature?

> Any info would be very welcome!!

> David

Now, it looks like I've sorted out the original problem. The solution
was to remove the data environment component, and all references to
it, from the .dll file, and replace these with references to a system
dsn.
It appears that this is much more reliable, at least when connecting
to a data source through a firewall.


Mon, 12 Apr 2004 17:25:14 GMT  
 
 [ 2 post ] 

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