Subject Re: [firebird-support] Connection invalid error
Author Helen Borrie
At 05:48 PM 9/07/2004 +0000, Jason wrote:
>Hello all,
>I'm using FB 1.5 on WinXP pro. My app is in delphi, using the IBO
>drivers. When I start stressing the system, with multiple clients
>connected to my middle tier, I will start getting "Connection invalid"
>errors (334455327 I believe). Once this behavior starts, I have to
>restart my middle tier (to close and restart the pooled connections)
>before things start behaving again. I took a look in the firebird log,
>and see these messages when it starts to mess up:
>IS-DEV03 (Server) Fri Jul 09 12:20:48 2004
> WNET/wnet_error: CreateFile errno = 2
>The .fdb file is local to the machine, not going through any drive
>mappings or substitutions. Any ideas?

This error comes from the Windows named pipes network. Is the magic number
10 connections? I suspect the thing you need to observe is whether you are
attempting to exceed the XP Pro limit of 10 active peer connections to your
application tier. The OS is barfing whenever the 11th client tries to
connect to the application.

If you are using tcp/ip with localhost ("local loopback server") for your
pooled connections, it won't be database connection limits you are
encountering here, since there's no built-in limit to the number of tcp/ip
connections. (TCP/IP errors are reported as "INET/inet_error"). If you're
planning to deploy this application on an XP Pro server, you'll need to
build some kind of limiting mechanism into your application tier to detect
and handle the WNET error and refuse the 11th connection in a friendly way.