Connecting to database

Posted by Admin on 24-Nov-2008 11:02

We use citrix as the thin client for our clients to connect to their progress databases, the reason beeing is that when their internet connection drops their seesion on the database remains open so when the connection becomes on again that they go dierectly to the screen that the were working on. Now I want to find out if when we change our systems so that our clients cponnect over a thick client (VPN) How will the progress database handle a drop in connectivity, if the 3G or adsl connection drops, will this close the session and what happens to the database itself?does progress roll back or is their a way of keeping the session alive.

Please can someone shed light on my issue?

Message was edited by:

Conrad van Stade

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Posted by Admin on 24-Nov-2008 11:42

Did you test your application with a 3G or ASDL network link? It may work - but it may as well be too slow. You should at least use the schema cache files (-cache).

When the connection drops, the database server get's notified by the OS (the tcp stack), that the connection is lost. The database server will then roll back and remove the current session from the user table. No way to re-connect to that session or even those transactions. Everything should be backed out.

Posted by Thomas Mercer-Hursh on 24-Nov-2008 11:56

To elaborate a little further on Mike's answer, in your Citrix environment the "client session" is actually running on the Citrix server and only an image of that session is going to the remote client. Thus, the remote client disconnecting from Citrix doesn't do anything to the session and it is possible to reconnect. I don't know anything about Citrix personally, but from your description, that must be what is happening. I'm not sure how such a session gets cleaned up.

But, if you go regular thick client and lose the connection, then it is the actual session which is losing connectivity with the database, not just the image. So, that session is going to get backed out, as Mike said. Not only won't it exist to reconnect to, you would have no way of reassociating with it even if it did still exist. While that might seem a pain from the point of view of having to renavigate to where you were, it is actually a good thing because Progress is cleaning up to insure integrity.

Posted by Admin on 24-Nov-2008 18:38

Are you changing systems from Citrix to VPN connection to remove Citrix from your network? Are you doing this for cost reasons? An alternative to Citrix is a Windows Server with Terminal Services, which essentially provides the same remote desktop capability as Citrix. If you're introducing VPN for security reasons, there's no reason to stop using either Citrix or Terminal Services for remote desktop.

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