At 06:44 AM 2/04/2009, you wrote:

>Hello:
>
>I have an application in Delphi which uses FireBird 2.0.1 Superserver.
>
>It is installed in an enterprise which has 8 users in a local network and 5 users in another building. These 5 users, use the application accesing via Terminal Server to the PC where the application is installed since 2 years ago.

How would these external users "access via terminal server"? Are they running their applications on a disk somewhere in the internal network?

>The application and the FDB files are in a PC which, till 2 months ago had Windows 2003 Server. Then they changed this to Windows XP (¡don´t ask why please!).

Windows XP disallows all *Windows networking* connections once the total connections of *any* sort exceeds the number of licences. That means counting connections to printers, etc., as well as all remote desktop instances. These "windows networking" limits do not apply to TCP/IP...although installations have their own default limits that, again, depends on which edition of XP they installed.

>This worked fine during 2 months, but this week it started a problem: 5, 6 or 7 times a day, every user (in the local network or by terminal server) looses contact with the database at the same time. When this happens, I check the Service Control Manager and I see that the service "Firebird Server - DefaultInstance" is started. Then, I stopped it (I get an error 1067 but it stops), I started it again, and then every user can connect again to the database... till the next time it fails.

Check whether they installed Service Pack 3, or perhaps one of the many update patches from Windows Update that have been popping up in recent weeks in response to the conficker worm virus. Either way, their network problems could be related: if they did install SP3 and the recent updates, their own users could be suffering the effects of the "protection"; if they didn't install them, they might be acting as a "zombie" for conficker.

SP3 by default hobbles TCP/IP to < 64 concurrent connections. If SP3 is in the picture, try googling for solutions. If this turns out to be the cause of the problem, maybe (after fixing the network issue) you need to look at why such a small number of "users" is accumulating such a large number of concurrent connections...for example, are they running the Guardian with Classic? etc.

For Firebird's part, it is stumped if the network is configured to block connection requests. It has no control over the network: it completely relies on the network transport's capability to provide sockets on request.

./heLen